/* vi:set ts=8 sts=4 sw=4 noet:
 *
 * VIM - Vi IMproved	by Bram Moolenaar
 *
 * Do ":help uganda"  in Vim to read copying and usage conditions.
 * Do ":help credits" in Vim to see a list of people who contributed.
 * See README.txt for an overview of the Vim source code.
 */

/*
 * ex_cmds.c: some functions for command line commands
 */

#include "version.h"
#include "vim.h"

#ifdef FEAT_FLOAT
#include <float.h>
#endif

static int linelen(int *has_tab);
static void do_filter(linenr_T line1, linenr_T line2, exarg_T *eap, char_u *cmd, int do_in, int do_out);
#ifdef FEAT_VIMINFO
static char_u *viminfo_filename(char_u *);
static void do_viminfo(FILE *fp_in, FILE *fp_out, int flags);
static int viminfo_encoding(vir_T *virp);
static int read_viminfo_up_to_marks(vir_T *virp, int forceit, int writing);
#endif

static int check_readonly(int *forceit, buf_T *buf);
static void delbuf_msg(char_u *name);
static int help_compare(const void *s1, const void *s2);
static void prepare_help_buffer(void);

/*
 * ":ascii" and "ga".
 */
void do_ascii(exarg_T *eap UNUSED)
{
  int c;
  int cval;
  char buf1[20];
  char buf2[20];
  char_u buf3[7];
#ifdef FEAT_DIGRAPHS
  char_u *dig;
#endif
  int cc[MAX_MCO];
  int ci = 0;
  int len;

  if (enc_utf8)
    c = utfc_ptr2char(ml_get_cursor(), cc);
  else
    c = gchar_cursor();
  if (c == NUL)
  {
    msg("NUL");
    return;
  }

  IObuff[0] = NUL;
  if (!has_mbyte || (enc_dbcs != 0 && c < 0x100) || c < 0x80)
  {
    if (c == NL) /* NUL is stored as NL */
      c = NUL;
    if (c == CAR && get_fileformat(curbuf) == EOL_MAC)
      cval = NL; /* NL is stored as CR */
    else
      cval = c;
    if (vim_isprintc_strict(c) && (c < ' '
#ifndef EBCDIC
                                   || c > '~'
#endif
                                   ))
    {
      transchar_nonprint(buf3, c);
      vim_snprintf(buf1, sizeof(buf1), "  <%s>", (char *)buf3);
    }
    else
      buf1[0] = NUL;
#ifndef EBCDIC
    if (c >= 0x80)
      vim_snprintf(buf2, sizeof(buf2), "  <M-%s>",
                   (char *)transchar(c & 0x7f));
    else
#endif
      buf2[0] = NUL;
#ifdef FEAT_DIGRAPHS
    dig = get_digraph_for_char(cval);
    if (dig != NULL)
      vim_snprintf((char *)IObuff, IOSIZE,
                   _("<%s>%s%s  %d,  Hex %02x,  Oct %03o, Digr %s"),
                   transchar(c), buf1, buf2, cval, cval, cval, dig);
    else
#endif
      vim_snprintf((char *)IObuff, IOSIZE,
                   _("<%s>%s%s  %d,  Hex %02x,  Octal %03o"),
                   transchar(c), buf1, buf2, cval, cval, cval);
    if (enc_utf8)
      c = cc[ci++];
    else
      c = 0;
  }

  /* Repeat for combining characters. */
  while (has_mbyte && (c >= 0x100 || (enc_utf8 && c >= 0x80)))
  {
    len = (int)STRLEN(IObuff);
    /* This assumes every multi-byte char is printable... */
    if (len > 0)
      IObuff[len++] = ' ';
    IObuff[len++] = '<';
    if (enc_utf8 && utf_iscomposing(c)
#ifdef USE_GUI
        && !gui.in_use
#endif
    )
      IObuff[len++] = ' '; /* draw composing char on top of a space */
    len += (*mb_char2bytes)(c, IObuff + len);
#ifdef FEAT_DIGRAPHS
    dig = get_digraph_for_char(c);
    if (dig != NULL)
      vim_snprintf((char *)IObuff + len, IOSIZE - len,
                   c < 0x10000 ? _("> %d, Hex %04x, Oct %o, Digr %s")
                               : _("> %d, Hex %08x, Oct %o, Digr %s"),
                   c, c, c, dig);
    else
#endif
      vim_snprintf((char *)IObuff + len, IOSIZE - len,
                   c < 0x10000 ? _("> %d, Hex %04x, Octal %o")
                               : _("> %d, Hex %08x, Octal %o"),
                   c, c, c);
    if (ci == MAX_MCO)
      break;
    if (enc_utf8)
      c = cc[ci++];
    else
      c = 0;
  }

  msg((char *)IObuff);
}

/*
 * ":left", ":center" and ":right": align text.
 */
void ex_align(exarg_T *eap)
{
  pos_T save_curpos;
  int len;
  int indent = 0;
  int new_indent;
  int has_tab;
  int width;

#ifdef FEAT_RIGHTLEFT
  if (curwin->w_p_rl)
  {
    /* switch left and right aligning */
    if (eap->cmdidx == CMD_right)
      eap->cmdidx = CMD_left;
    else if (eap->cmdidx == CMD_left)
      eap->cmdidx = CMD_right;
  }
#endif

  width = atoi((char *)eap->arg);
  save_curpos = curwin->w_cursor;
  if (eap->cmdidx == CMD_left) /* width is used for new indent */
  {
    if (width >= 0)
      indent = width;
  }
  else
  {
    /*
	 * if 'textwidth' set, use it
	 * else if 'wrapmargin' set, use it
	 * if invalid value, use 80
	 */
    if (width <= 0)
      width = curbuf->b_p_tw;
    if (width == 0 && curbuf->b_p_wm > 0)
      width = curwin->w_width - curbuf->b_p_wm;
    if (width <= 0)
      width = 80;
  }

  if (u_save((linenr_T)(eap->line1 - 1), (linenr_T)(eap->line2 + 1)) == FAIL)
    return;

  for (curwin->w_cursor.lnum = eap->line1;
       curwin->w_cursor.lnum <= eap->line2; ++curwin->w_cursor.lnum)
  {
    if (eap->cmdidx == CMD_left) /* left align */
      new_indent = indent;
    else
    {
      has_tab = FALSE; /* avoid uninit warnings */
      len = linelen(eap->cmdidx == CMD_right ? &has_tab
                                             : NULL) -
            get_indent();

      if (len <= 0) /* skip blank lines */
        continue;

      if (eap->cmdidx == CMD_center)
        new_indent = (width - len) / 2;
      else
      {
        new_indent = width - len; /* right align */

        /*
		 * Make sure that embedded TABs don't make the text go too far
		 * to the right.
		 */
        if (has_tab)
          while (new_indent > 0)
          {
            (void)set_indent(new_indent, 0);
            if (linelen(NULL) <= width)
            {
              /*
			     * Now try to move the line as much as possible to
			     * the right.  Stop when it moves too far.
			     */
              do
                (void)set_indent(++new_indent, 0);
              while (linelen(NULL) <= width);
              --new_indent;
              break;
            }
            --new_indent;
          }
      }
    }
    if (new_indent < 0)
      new_indent = 0;
    (void)set_indent(new_indent, 0); /* set indent */
  }
  changed_lines(eap->line1, 0, eap->line2 + 1, 0L);
  curwin->w_cursor = save_curpos;
  beginline(BL_WHITE | BL_FIX);
}

/*
 * Get the length of the current line, excluding trailing white space.
 */
static int
linelen(int *has_tab)
{
  char_u *line;
  char_u *first;
  char_u *last;
  int save;
  int len;

  /* find the first non-blank character */
  line = ml_get_curline();
  first = skipwhite(line);

  /* find the character after the last non-blank character */
  for (last = first + STRLEN(first);
       last > first && VIM_ISWHITE(last[-1]); --last)
    ;
  save = *last;
  *last = NUL;
  len = linetabsize(line); /* get line length */
  if (has_tab != NULL)     /* check for embedded TAB */
    *has_tab = (vim_strchr(first, TAB) != NULL);
  *last = save;

  return len;
}

/* Buffer for two lines used during sorting.  They are allocated to
 * contain the longest line being sorted. */
static char_u *sortbuf1;
static char_u *sortbuf2;

static int sort_ic; /* ignore case */
static int sort_nr; /* sort on number */
static int sort_rx; /* sort on regex instead of skipping it */
#ifdef FEAT_FLOAT
static int sort_flt; /* sort on floating number */
#endif

static int sort_abort; /* flag to indicate if sorting has been interrupted */

/* Struct to store info to be sorted. */
typedef struct
{
  linenr_T lnum; // line number
  union
  {
    struct
    {
      varnumber_T start_col_nr; // starting column number
      varnumber_T end_col_nr;   // ending column number
    } line;
    struct
    {
      varnumber_T value; // value if sorting by integer
      int is_number;     // TRUE when line contains a number
    } num;
#ifdef FEAT_FLOAT
    float_T value_flt; // value if sorting by float
#endif
  } st_u;
} sorti_T;

static int sort_compare(const void *s1, const void *s2);

static int
sort_compare(const void *s1, const void *s2)
{
  sorti_T l1 = *(sorti_T *)s1;
  sorti_T l2 = *(sorti_T *)s2;
  int result = 0;

  /* If the user interrupts, there's no way to stop qsort() immediately, but
     * if we return 0 every time, qsort will assume it's done sorting and
     * exit. */
  if (sort_abort)
    return 0;
  fast_breakcheck();
  if (got_int)
    sort_abort = TRUE;

  if (sort_nr)
  {
    if (l1.st_u.num.is_number != l2.st_u.num.is_number)
      result = l1.st_u.num.is_number - l2.st_u.num.is_number;
    else
      result = l1.st_u.num.value == l2.st_u.num.value ? 0
                                                      : l1.st_u.num.value > l2.st_u.num.value ? 1 : -1;
  }
#ifdef FEAT_FLOAT
  else if (sort_flt)
    result = l1.st_u.value_flt == l2.st_u.value_flt ? 0
                                                    : l1.st_u.value_flt > l2.st_u.value_flt ? 1 : -1;
#endif
  else
  {
    /* We need to copy one line into "sortbuf1", because there is no
	 * guarantee that the first pointer becomes invalid when obtaining the
	 * second one. */
    STRNCPY(sortbuf1, ml_get(l1.lnum) + l1.st_u.line.start_col_nr,
            l1.st_u.line.end_col_nr - l1.st_u.line.start_col_nr + 1);
    sortbuf1[l1.st_u.line.end_col_nr - l1.st_u.line.start_col_nr] = 0;
    STRNCPY(sortbuf2, ml_get(l2.lnum) + l2.st_u.line.start_col_nr,
            l2.st_u.line.end_col_nr - l2.st_u.line.start_col_nr + 1);
    sortbuf2[l2.st_u.line.end_col_nr - l2.st_u.line.start_col_nr] = 0;

    result = sort_ic ? STRICMP(sortbuf1, sortbuf2)
                     : STRCMP(sortbuf1, sortbuf2);
  }

  /* If two lines have the same value, preserve the original line order. */
  if (result == 0)
    return (int)(l1.lnum - l2.lnum);
  return result;
}

/*
 * ":sort".
 */
void ex_sort(exarg_T *eap)
{
  regmatch_T regmatch;
  int len;
  linenr_T lnum;
  long maxlen = 0;
  sorti_T *nrs;
  size_t count = (size_t)(eap->line2 - eap->line1 + 1);
  size_t i;
  char_u *p;
  char_u *s;
  char_u *s2;
  char_u c; /* temporary character storage */
  int unique = FALSE;
  long deleted;
  colnr_T start_col;
  colnr_T end_col;
  int sort_what = 0;
  int format_found = 0;
  int change_occurred = FALSE; // Buffer contents changed.

  /* Sorting one line is really quick! */
  if (count <= 1)
    return;

  if (u_save((linenr_T)(eap->line1 - 1), (linenr_T)(eap->line2 + 1)) == FAIL)
    return;
  sortbuf1 = NULL;
  sortbuf2 = NULL;
  regmatch.regprog = NULL;
  nrs = ALLOC_MULT(sorti_T, count);
  if (nrs == NULL)
    goto sortend;

  sort_abort = sort_ic = sort_rx = sort_nr = 0;
#ifdef FEAT_FLOAT
  sort_flt = 0;
#endif

  for (p = eap->arg; *p != NUL; ++p)
  {
    if (VIM_ISWHITE(*p))
      ;
    else if (*p == 'i')
      sort_ic = TRUE;
    else if (*p == 'r')
      sort_rx = TRUE;
    else if (*p == 'n')
    {
      sort_nr = 1;
      ++format_found;
    }
#ifdef FEAT_FLOAT
    else if (*p == 'f')
    {
      sort_flt = 1;
      ++format_found;
    }
#endif
    else if (*p == 'b')
    {
      sort_what = STR2NR_BIN + STR2NR_FORCE;
      ++format_found;
    }
    else if (*p == 'o')
    {
      sort_what = STR2NR_OCT + STR2NR_FORCE;
      ++format_found;
    }
    else if (*p == 'x')
    {
      sort_what = STR2NR_HEX + STR2NR_FORCE;
      ++format_found;
    }
    else if (*p == 'u')
      unique = TRUE;
    else if (*p == '"') /* comment start */
      break;
    else if (check_nextcmd(p) != NULL)
    {
      eap->nextcmd = check_nextcmd(p);
      break;
    }
    else if (!ASCII_ISALPHA(*p) && regmatch.regprog == NULL)
    {
      s = skip_regexp(p + 1, *p, TRUE, NULL);
      if (*s != *p)
      {
        emsg(_(e_invalpat));
        goto sortend;
      }
      *s = NUL;
      /* Use last search pattern if sort pattern is empty. */
      if (s == p + 1)
      {
        if (last_search_pat() == NULL)
        {
          emsg(_(e_noprevre));
          goto sortend;
        }
        regmatch.regprog = vim_regcomp(last_search_pat(), RE_MAGIC);
      }
      else
        regmatch.regprog = vim_regcomp(p + 1, RE_MAGIC);
      if (regmatch.regprog == NULL)
        goto sortend;
      p = s; /* continue after the regexp */
      regmatch.rm_ic = p_ic;
    }
    else
    {
      semsg(_(e_invarg2), p);
      goto sortend;
    }
  }

  /* Can only have one of 'n', 'b', 'o' and 'x'. */
  if (format_found > 1)
  {
    emsg(_(e_invarg));
    goto sortend;
  }

  /* From here on "sort_nr" is used as a flag for any integer number
     * sorting. */
  sort_nr += sort_what;

  /*
     * Make an array with all line numbers.  This avoids having to copy all
     * the lines into allocated memory.
     * When sorting on strings "start_col_nr" is the offset in the line, for
     * numbers sorting it's the number to sort on.  This means the pattern
     * matching and number conversion only has to be done once per line.
     * Also get the longest line length for allocating "sortbuf".
     */
  for (lnum = eap->line1; lnum <= eap->line2; ++lnum)
  {
    s = ml_get(lnum);
    len = (int)STRLEN(s);
    if (maxlen < len)
      maxlen = len;

    start_col = 0;
    end_col = len;
    if (regmatch.regprog != NULL && vim_regexec(&regmatch, s, 0))
    {
      if (sort_rx)
      {
        start_col = (colnr_T)(regmatch.startp[0] - s);
        end_col = (colnr_T)(regmatch.endp[0] - s);
      }
      else
        start_col = (colnr_T)(regmatch.endp[0] - s);
    }
    else if (regmatch.regprog != NULL)
      end_col = 0;

    if (sort_nr
#ifdef FEAT_FLOAT
        || sort_flt
#endif
    )
    {
      /* Make sure vim_str2nr doesn't read any digits past the end
	     * of the match, by temporarily terminating the string there */
      s2 = s + end_col;
      c = *s2;
      *s2 = NUL;
      /* Sorting on number: Store the number itself. */
      p = s + start_col;
      if (sort_nr)
      {
        if (sort_what & STR2NR_HEX)
          s = skiptohex(p);
        else if (sort_what & STR2NR_BIN)
          s = skiptobin(p);
        else
          s = skiptodigit(p);
        if (s > p && s[-1] == '-')
          --s; /* include preceding negative sign */
        if (*s == NUL)
        {
          /* line without number should sort before any number */
          nrs[lnum - eap->line1].st_u.num.is_number = FALSE;
          nrs[lnum - eap->line1].st_u.num.value = 0;
        }
        else
        {
          nrs[lnum - eap->line1].st_u.num.is_number = TRUE;
          vim_str2nr(s, NULL, NULL, sort_what,
                     &nrs[lnum - eap->line1].st_u.num.value,
                     NULL, 0, FALSE);
        }
      }
#ifdef FEAT_FLOAT
      else
      {
        s = skipwhite(p);
        if (*s == '+')
          s = skipwhite(s + 1);

        if (*s == NUL)
          /* empty line should sort before any number */
          nrs[lnum - eap->line1].st_u.value_flt = -DBL_MAX;
        else
          nrs[lnum - eap->line1].st_u.value_flt =
              strtod((char *)s, NULL);
      }
#endif
      *s2 = c;
    }
    else
    {
      /* Store the column to sort at. */
      nrs[lnum - eap->line1].st_u.line.start_col_nr = start_col;
      nrs[lnum - eap->line1].st_u.line.end_col_nr = end_col;
    }

    nrs[lnum - eap->line1].lnum = lnum;

    if (regmatch.regprog != NULL)
      fast_breakcheck();
    if (got_int)
      goto sortend;
  }

  /* Allocate a buffer that can hold the longest line. */
  sortbuf1 = alloc(maxlen + 1);
  if (sortbuf1 == NULL)
    goto sortend;
  sortbuf2 = alloc(maxlen + 1);
  if (sortbuf2 == NULL)
    goto sortend;

  /* Sort the array of line numbers.  Note: can't be interrupted! */
  qsort((void *)nrs, count, sizeof(sorti_T), sort_compare);

  if (sort_abort)
    goto sortend;

  /* Insert the lines in the sorted order below the last one. */
  lnum = eap->line2;
  for (i = 0; i < count; ++i)
  {
    linenr_T get_lnum = nrs[eap->forceit ? count - i - 1 : i].lnum;

    // If the original line number of the line being placed is not the same
    // as "lnum" (accounting for offset), we know that the buffer changed.
    if (get_lnum + ((linenr_T)count - 1) != lnum)
      change_occurred = TRUE;

    s = ml_get(get_lnum);
    if (!unique || i == 0 || (sort_ic ? STRICMP(s, sortbuf1) : STRCMP(s, sortbuf1)) != 0)
    {
      // Copy the line into a buffer, it may become invalid in
      // ml_append(). And it's needed for "unique".
      STRCPY(sortbuf1, s);
      if (ml_append(lnum++, sortbuf1, (colnr_T)0, FALSE) == FAIL)
        break;
    }
    fast_breakcheck();
    if (got_int)
      goto sortend;
  }

  /* delete the original lines if appending worked */
  if (i == count)
    for (i = 0; i < count; ++i)
      ml_delete(eap->line1, FALSE);
  else
    count = 0;

  /* Adjust marks for deleted (or added) lines and prepare for displaying. */
  deleted = (long)(count - (lnum - eap->line2));
  if (deleted > 0)
  {
    mark_adjust(eap->line2 - deleted, eap->line2, (long)MAXLNUM, -deleted);
    msgmore(-deleted);
  }
  else if (deleted < 0)
    mark_adjust(eap->line2, MAXLNUM, -deleted, 0L);

  if (change_occurred || deleted != 0)
    changed_lines(eap->line1, 0, eap->line2 + 1, -deleted);

  curwin->w_cursor.lnum = eap->line1;
  beginline(BL_WHITE | BL_FIX);

sortend:
  vim_free(nrs);
  vim_free(sortbuf1);
  vim_free(sortbuf2);
  vim_regfree(regmatch.regprog);
  if (got_int)
    emsg(_(e_interr));
}

/*
 * ":retab".
 */
void ex_retab(exarg_T *eap)
{
  linenr_T lnum;
  int got_tab = FALSE;
  long num_spaces = 0;
  long num_tabs;
  long len;
  long col;
  long vcol;
  long start_col = 0;  /* For start of white-space string */
  long start_vcol = 0; /* For start of white-space string */
  long old_len;
  char_u *ptr;
  char_u *new_line = (char_u *)1; /* init to non-NULL */
  int did_undo;                   /* called u_save for current line */
#ifdef FEAT_VARTABS
  int *new_vts_array = NULL;
  char_u *new_ts_str; /* string value of tab argument */
#else
  int temp;
  int new_ts;
#endif
  int save_list;
  linenr_T first_line = 0; /* first changed line */
  linenr_T last_line = 0;  /* last changed line */

  save_list = curwin->w_p_list;
  curwin->w_p_list = 0; /* don't want list mode here */

#ifdef FEAT_VARTABS
  new_ts_str = eap->arg;
  if (!tabstop_set(eap->arg, &new_vts_array))
    return;
  while (vim_isdigit(*(eap->arg)) || *(eap->arg) == ',')
    ++(eap->arg);

  // This ensures that either new_vts_array and new_ts_str are freshly
  // allocated, or new_vts_array points to an existing array and new_ts_str
  // is null.
  if (new_vts_array == NULL)
  {
    new_vts_array = curbuf->b_p_vts_array;
    new_ts_str = NULL;
  }
  else
    new_ts_str = vim_strnsave(new_ts_str, eap->arg - new_ts_str);
#else
  new_ts = getdigits(&(eap->arg));
  if (new_ts < 0)
  {
    emsg(_(e_positive));
    return;
  }
  if (new_ts == 0)
    new_ts = curbuf->b_p_ts;
#endif
  for (lnum = eap->line1; !got_int && lnum <= eap->line2; ++lnum)
  {
    ptr = ml_get(lnum);
    col = 0;
    vcol = 0;
    did_undo = FALSE;
    for (;;)
    {
      if (VIM_ISWHITE(ptr[col]))
      {
        if (!got_tab && num_spaces == 0)
        {
          /* First consecutive white-space */
          start_vcol = vcol;
          start_col = col;
        }
        if (ptr[col] == ' ')
          num_spaces++;
        else
          got_tab = TRUE;
      }
      else
      {
        if (got_tab || (eap->forceit && num_spaces > 1))
        {
          /* Retabulate this string of white-space */

          /* len is virtual length of white string */
          len = num_spaces = vcol - start_vcol;
          num_tabs = 0;
          if (!curbuf->b_p_et)
          {
#ifdef FEAT_VARTABS
            int t, s;

            tabstop_fromto(start_vcol, vcol,
                           curbuf->b_p_ts, new_vts_array, &t, &s);
            num_tabs = t;
            num_spaces = s;
#else
            temp = new_ts - (start_vcol % new_ts);
            if (num_spaces >= temp)
            {
              num_spaces -= temp;
              num_tabs++;
            }
            num_tabs += num_spaces / new_ts;
            num_spaces -= (num_spaces / new_ts) * new_ts;
#endif
          }
          if (curbuf->b_p_et || got_tab ||
              (num_spaces + num_tabs < len))
          {
            if (did_undo == FALSE)
            {
              did_undo = TRUE;
              if (u_save((linenr_T)(lnum - 1),
                         (linenr_T)(lnum + 1)) == FAIL)
              {
                new_line = NULL; /* flag out-of-memory */
                break;
              }
            }

            /* len is actual number of white characters used */
            len = num_spaces + num_tabs;
            old_len = (long)STRLEN(ptr);
            new_line = alloc(old_len - col + start_col + len + 1);
            if (new_line == NULL)
              break;
            if (start_col > 0)
              mch_memmove(new_line, ptr, (size_t)start_col);
            mch_memmove(new_line + start_col + len,
                        ptr + col, (size_t)(old_len - col + 1));
            ptr = new_line + start_col;
            for (col = 0; col < len; col++)
              ptr[col] = (col < num_tabs) ? '\t' : ' ';
            ml_replace(lnum, new_line, FALSE);
            if (first_line == 0)
              first_line = lnum;
            last_line = lnum;
            ptr = new_line;
            col = start_col + len;
          }
        }
        got_tab = FALSE;
        num_spaces = 0;
      }
      if (ptr[col] == NUL)
        break;
      vcol += chartabsize(ptr + col, (colnr_T)vcol);
      if (has_mbyte)
        col += (*mb_ptr2len)(ptr + col);
      else
        ++col;
    }
    if (new_line == NULL) /* out of memory */
      break;
    line_breakcheck();
  }
  if (got_int)
    emsg(_(e_interr));

#ifdef FEAT_VARTABS
  // If a single value was given then it can be considered equal to
  // either the value of 'tabstop' or the value of 'vartabstop'.
  if (tabstop_count(curbuf->b_p_vts_array) == 0 && tabstop_count(new_vts_array) == 1 && curbuf->b_p_ts == tabstop_first(new_vts_array))
    ; /* not changed */
  else if (tabstop_count(curbuf->b_p_vts_array) > 0 && tabstop_eq(curbuf->b_p_vts_array, new_vts_array))
    ; /* not changed */
  else
    redraw_curbuf_later(NOT_VALID);
#else
  if (curbuf->b_p_ts != new_ts)
    redraw_curbuf_later(NOT_VALID);
#endif
  if (first_line != 0)
    changed_lines(first_line, 0, last_line + 1, 0L);

  curwin->w_p_list = save_list; /* restore 'list' */

#ifdef FEAT_VARTABS
  if (new_ts_str != NULL) /* set the new tabstop */
  {
    // If 'vartabstop' is in use or if the value given to retab has more
    // than one tabstop then update 'vartabstop'.
    int *old_vts_ary = curbuf->b_p_vts_array;

    if (tabstop_count(old_vts_ary) > 0 || tabstop_count(new_vts_array) > 1)
    {
      set_string_option_direct((char_u *)"vts", -1, new_ts_str,
                               OPT_FREE | OPT_LOCAL, 0);
      curbuf->b_p_vts_array = new_vts_array;
      vim_free(old_vts_ary);
    }
    else
    {
      // 'vartabstop' wasn't in use and a single value was given to
      // retab then update 'tabstop'.
      curbuf->b_p_ts = tabstop_first(new_vts_array);
      vim_free(new_vts_array);
    }
    vim_free(new_ts_str);
  }
#else
  curbuf->b_p_ts = new_ts;
#endif
  coladvance(curwin->w_curswant);

  u_clearline();
}

/*
 * :move command - move lines line1-line2 to line dest
 *
 * return FAIL for failure, OK otherwise
 */
int do_move(linenr_T line1, linenr_T line2, linenr_T dest)
{
  char_u *str;
  linenr_T l;
  linenr_T extra;     // Num lines added before line1
  linenr_T num_lines; // Num lines moved
  linenr_T last_line; // Last line in file after adding new text
#ifdef FEAT_FOLDING
  win_T *win;
  tabpage_T *tp;
#endif

  if (dest >= line1 && dest < line2)
  {
    emsg(_("E134: Cannot move a range of lines into itself"));
    return FAIL;
  }

  // Do nothing if we are not actually moving any lines.  This will prevent
  // the 'modified' flag from being set without cause.
  if (dest == line1 - 1 || dest == line2)
  {
    // Move the cursor as if lines were moved (see below) to be backwards
    // compatible.
    if (dest >= line1)
      curwin->w_cursor.lnum = dest;
    else
      curwin->w_cursor.lnum = dest + (line2 - line1) + 1;

    return OK;
  }

  num_lines = line2 - line1 + 1;

  /*
     * First we copy the old text to its new location -- webb
     * Also copy the flag that ":global" command uses.
     */
  if (u_save(dest, dest + 1) == FAIL)
    return FAIL;
  for (extra = 0, l = line1; l <= line2; l++)
  {
    str = vim_strsave(ml_get(l + extra));
    if (str != NULL)
    {
      ml_append(dest + l - line1, str, (colnr_T)0, FALSE);
      vim_free(str);
      if (dest < line1)
        extra++;
    }
  }

  /*
     * Now we must be careful adjusting our marks so that we don't overlap our
     * mark_adjust() calls.
     *
     * We adjust the marks within the old text so that they refer to the
     * last lines of the file (temporarily), because we know no other marks
     * will be set there since these line numbers did not exist until we added
     * our new lines.
     *
     * Then we adjust the marks on lines between the old and new text positions
     * (either forwards or backwards).
     *
     * And Finally we adjust the marks we put at the end of the file back to
     * their final destination at the new text position -- webb
     */
  last_line = curbuf->b_ml.ml_line_count;
  mark_adjust_nofold(line1, line2, last_line - line2, 0L);
  if (dest >= line2)
  {
    mark_adjust_nofold(line2 + 1, dest, -num_lines, 0L);
#ifdef FEAT_FOLDING
    FOR_ALL_TAB_WINDOWS(tp, win)
    {
      if (win->w_buffer == curbuf)
        foldMoveRange(&win->w_folds, line1, line2, dest);
    }
#endif
    curbuf->b_op_start.lnum = dest - num_lines + 1;
    curbuf->b_op_end.lnum = dest;
  }
  else
  {
    mark_adjust_nofold(dest + 1, line1 - 1, num_lines, 0L);
#ifdef FEAT_FOLDING
    FOR_ALL_TAB_WINDOWS(tp, win)
    {
      if (win->w_buffer == curbuf)
        foldMoveRange(&win->w_folds, dest + 1, line1 - 1, line2);
    }
#endif
    curbuf->b_op_start.lnum = dest + 1;
    curbuf->b_op_end.lnum = dest + num_lines;
  }
  curbuf->b_op_start.col = curbuf->b_op_end.col = 0;
  mark_adjust_nofold(last_line - num_lines + 1, last_line,
                     -(last_line - dest - extra), 0L);

  /*
     * Now we delete the original text -- webb
     */
  if (u_save(line1 + extra - 1, line2 + extra + 1) == FAIL)
    return FAIL;

  for (l = line1; l <= line2; l++)
    ml_delete(line1 + extra, TRUE);

  if (!global_busy && num_lines > p_report)
    smsg(NGETTEXT("%ld line moved", "%ld lines moved", num_lines),
         (long)num_lines);

  /*
     * Leave the cursor on the last of the moved lines.
     */
  if (dest >= line1)
    curwin->w_cursor.lnum = dest;
  else
    curwin->w_cursor.lnum = dest + (line2 - line1) + 1;

  if (line1 < dest)
  {
    dest += num_lines + 1;
    last_line = curbuf->b_ml.ml_line_count;
    if (dest > last_line + 1)
      dest = last_line + 1;
    changed_lines(line1, 0, dest, 0L);
  }
  else
    changed_lines(dest + 1, 0, line1 + num_lines, 0L);

  return OK;
}

/*
 * ":copy"
 */
void ex_copy(linenr_T line1, linenr_T line2, linenr_T n)
{
  linenr_T count;
  char_u *p;

  count = line2 - line1 + 1;
  curbuf->b_op_start.lnum = n + 1;
  curbuf->b_op_end.lnum = n + count;
  curbuf->b_op_start.col = curbuf->b_op_end.col = 0;

  /*
     * there are three situations:
     * 1. destination is above line1
     * 2. destination is between line1 and line2
     * 3. destination is below line2
     *
     * n = destination (when starting)
     * curwin->w_cursor.lnum = destination (while copying)
     * line1 = start of source (while copying)
     * line2 = end of source (while copying)
     */
  if (u_save(n, n + 1) == FAIL)
    return;

  curwin->w_cursor.lnum = n;
  while (line1 <= line2)
  {
    /* need to use vim_strsave() because the line will be unlocked within
	 * ml_append() */
    p = vim_strsave(ml_get(line1));
    if (p != NULL)
    {
      ml_append(curwin->w_cursor.lnum, p, (colnr_T)0, FALSE);
      vim_free(p);
    }
    /* situation 2: skip already copied lines */
    if (line1 == n)
      line1 = curwin->w_cursor.lnum;
    ++line1;
    if (curwin->w_cursor.lnum < line1)
      ++line1;
    if (curwin->w_cursor.lnum < line2)
      ++line2;
    ++curwin->w_cursor.lnum;
  }

  appended_lines_mark(n, count);

  msgmore((long)count);
}

static char_u *prevcmd = NULL; /* the previous command */

#if defined(EXITFREE) || defined(PROTO)
void free_prev_shellcmd(void)
{
  vim_free(prevcmd);
}
#endif

/*
 * Handle the ":!cmd" command.	Also for ":r !cmd" and ":w !cmd"
 * Bangs in the argument are replaced with the previously entered command.
 * Remember the argument.
 */
void do_bang(
    int addr_count,
    exarg_T *eap,
    int forceit,
    int do_in,
    int do_out)
{
  char_u *arg = eap->arg;      /* command */
  linenr_T line1 = eap->line1; /* start of range */
  linenr_T line2 = eap->line2; /* end of range */
  char_u *newcmd = NULL;       /* the new command */
  int free_newcmd = FALSE;     /* need to free() newcmd */
  int ins_prevcmd;
  char_u *t;
  char_u *p;
  char_u *trailarg;
  int len;
  int scroll_save = msg_scroll;

  /*
     * Disallow shell commands for "rvim".
     * Disallow shell commands from .exrc and .vimrc in current directory for
     * security reasons.
     */
  if (check_restricted() || check_secure())
    return;

  if (addr_count == 0) /* :! */
  {
    msg_scroll = FALSE; /* don't scroll here */
    autowrite_all();
    msg_scroll = scroll_save;
  }

  /*
     * Try to find an embedded bang, like in :!<cmd> ! [args]
     * (:!! is indicated by the 'forceit' variable)
     */
  ins_prevcmd = forceit;
  trailarg = arg;
  do
  {
    len = (int)STRLEN(trailarg) + 1;
    if (newcmd != NULL)
      len += (int)STRLEN(newcmd);
    if (ins_prevcmd)
    {
      if (prevcmd == NULL)
      {
        emsg(_(e_noprev));
        vim_free(newcmd);
        return;
      }
      len += (int)STRLEN(prevcmd);
    }
    if ((t = alloc(len)) == NULL)
    {
      vim_free(newcmd);
      return;
    }
    *t = NUL;
    if (newcmd != NULL)
      STRCAT(t, newcmd);
    if (ins_prevcmd)
      STRCAT(t, prevcmd);
    p = t + STRLEN(t);
    STRCAT(t, trailarg);
    vim_free(newcmd);
    newcmd = t;

    /*
	 * Scan the rest of the argument for '!', which is replaced by the
	 * previous command.  "\!" is replaced by "!" (this is vi compatible).
	 */
    trailarg = NULL;
    while (*p)
    {
      if (*p == '!')
      {
        if (p > newcmd && p[-1] == '\\')
          STRMOVE(p - 1, p);
        else
        {
          trailarg = p;
          *trailarg++ = NUL;
          ins_prevcmd = TRUE;
          break;
        }
      }
      ++p;
    }
  } while (trailarg != NULL);

  vim_free(prevcmd);
  prevcmd = newcmd;

  if (bangredo) /* put cmd in redo buffer for ! command */
  {
    /* If % or # appears in the command, it must have been escaped.
	 * Reescape them, so that redoing them does not substitute them by the
	 * buffername. */
    char_u *cmd = vim_strsave_escaped(prevcmd, (char_u *)"%#");

    if (cmd != NULL)
    {
      AppendToRedobuffLit(cmd, -1);
      vim_free(cmd);
    }
    else
      AppendToRedobuffLit(prevcmd, -1);
    AppendToRedobuff((char_u *)"\n");
    bangredo = FALSE;
  }

  /*
     * Add quotes around the command, for shells that need them.
     */
  if (*p_shq != NUL)
  {
    newcmd = alloc(STRLEN(prevcmd) + 2 * STRLEN(p_shq) + 1);
    if (newcmd == NULL)
      return;
    STRCPY(newcmd, p_shq);
    STRCAT(newcmd, prevcmd);
    STRCAT(newcmd, p_shq);
    free_newcmd = TRUE;
  }
  if (addr_count == 0) /* :! */
  {
    /* echo the command */
    char_u *buffer = get_cmd_output(newcmd, NULL,
                                    0, NULL);

    if (outputCallback != NULL)
    {
      outputCallback(newcmd, buffer, msg_silent);
    }

    vim_free(buffer);
  }
  else /* :range! */
  {
    /* Careful: This may recursively call do_bang() again! (because of
	 * autocommands) */
    do_filter(line1, line2, eap, newcmd, do_in, do_out);
    apply_autocmds(EVENT_SHELLFILTERPOST, NULL, NULL, FALSE, curbuf);
  }
  if (free_newcmd)
    vim_free(newcmd);
}

/*
 * do_filter: filter lines through a command given by the user
 *
 * We mostly use temp files and the call_shell() routine here. This would
 * normally be done using pipes on a UNIX machine, but this is more portable
 * to non-unix machines. The call_shell() routine needs to be able
 * to deal with redirection somehow, and should handle things like looking
 * at the PATH env. variable, and adding reasonable extensions to the
 * command name given by the user. All reasonable versions of call_shell()
 * do this.
 * Alternatively, if on Unix and redirecting input or output, but not both,
 * and the 'shelltemp' option isn't set, use pipes.
 * We use input redirection if do_in is TRUE.
 * We use output redirection if do_out is TRUE.
 */
static void
do_filter(
    linenr_T line1,
    linenr_T line2,
    exarg_T *eap, /* for forced 'ff' and 'fenc' */
    char_u *cmd,
    int do_in,
    int do_out)
{
  char_u *itmp = NULL;
  char_u *otmp = NULL;
  linenr_T linecount;
  linenr_T read_linecount;
  pos_T cursor_save;
  char_u *cmd_buf;
  buf_T *old_curbuf = curbuf;
  int shell_flags = 0;

  if (*cmd == NUL) /* no filter command */
    return;

  cursor_save = curwin->w_cursor;
  linecount = line2 - line1 + 1;
  curwin->w_cursor.lnum = line1;
  curwin->w_cursor.col = 0;
  changed_line_abv_curs();
  invalidate_botline();

  /*
     * When using temp files:
     * 1. * Form temp file names
     * 2. * Write the lines to a temp file
     * 3.   Run the filter command on the temp file
     * 4. * Read the output of the command into the buffer
     * 5. * Delete the original lines to be filtered
     * 6. * Remove the temp files
     *
     * When writing the input with a pipe or when catching the output with a
     * pipe only need to do 3.
     */

  if (do_out)
    shell_flags |= SHELL_DOOUT;

#ifdef FEAT_FILTERPIPE
  if (!do_in && do_out && !p_stmp)
  {
    /* Use a pipe to fetch stdout of the command, do not use a temp file. */
    shell_flags |= SHELL_READ;
    curwin->w_cursor.lnum = line2;
  }
  else if (do_in && !do_out && !p_stmp)
  {
    /* Use a pipe to write stdin of the command, do not use a temp file. */
    shell_flags |= SHELL_WRITE;
    curbuf->b_op_start.lnum = line1;
    curbuf->b_op_end.lnum = line2;
  }
  else if (do_in && do_out && !p_stmp)
  {
    /* Use a pipe to write stdin and fetch stdout of the command, do not
	 * use a temp file. */
    shell_flags |= SHELL_READ | SHELL_WRITE;
    curbuf->b_op_start.lnum = line1;
    curbuf->b_op_end.lnum = line2;
    curwin->w_cursor.lnum = line2;
  }
  else
#endif
      if ((do_in && (itmp = vim_tempname('i', FALSE)) == NULL) || (do_out && (otmp = vim_tempname('o', FALSE)) == NULL))
  {
    emsg(_(e_notmp));
    goto filterend;
  }

  /*
 * The writing and reading of temp files will not be shown.
 * Vi also doesn't do this and the messages are not very informative.
 */
  ++no_wait_return; /* don't call wait_return() while busy */
  if (itmp != NULL && buf_write(curbuf, itmp, NULL, line1, line2, eap,
                                FALSE, FALSE, FALSE, TRUE) == FAIL)
  {
    msg_putchar('\n'); /* keep message from buf_write() */
    --no_wait_return;
#if defined(FEAT_EVAL)
    if (!aborting())
#endif
      (void)semsg(_(e_notcreate), itmp); /* will call wait_return */
    goto filterend;
  }
  if (curbuf != old_curbuf)
    goto filterend;

  if (!do_out)
    msg_putchar('\n');

  /* Create the shell command in allocated memory. */
  cmd_buf = make_filter_cmd(cmd, itmp, otmp);
  if (cmd_buf == NULL)
    goto filterend;

  windgoto((int)Rows - 1, 0);
  cursor_on();

  /*
     * When not redirecting the output the command can write anything to the
     * screen. If 'shellredir' is equal to ">", screen may be messed up by
     * stderr output of external command. Clear the screen later.
     * If do_in is FALSE, this could be something like ":r !cat", which may
     * also mess up the screen, clear it later.
     */
  if (!do_out || STRCMP(p_srr, ">") == 0 || !do_in)
    redraw_later_clear();

  if (do_out)
  {
    if (u_save((linenr_T)(line2), (linenr_T)(line2 + 1)) == FAIL)
    {
      vim_free(cmd_buf);
      goto error;
    }
    redraw_curbuf_later(VALID);
  }
  read_linecount = curbuf->b_ml.ml_line_count;

  /*
     * When call_shell() fails wait_return() is called to give the user a
     * chance to read the error messages. Otherwise errors are ignored, so you
     * can see the error messages from the command that appear on stdout; use
     * 'u' to fix the text
     * Switch to cooked mode when not redirecting stdin, avoids that something
     * like ":r !cat" hangs.
     * Pass on the SHELL_DOOUT flag when the output is being redirected.
     */
  if (call_shell(cmd_buf, SHELL_FILTER | SHELL_COOKED | shell_flags))
  {
    redraw_later_clear();
    wait_return(FALSE);
  }
  vim_free(cmd_buf);

  did_check_timestamps = FALSE;
  need_check_timestamps = TRUE;

  /* When interrupting the shell command, it may still have produced some
     * useful output.  Reset got_int here, so that readfile() won't cancel
     * reading. */
  ui_breakcheck();
  got_int = FALSE;

  if (do_out)
  {
    if (otmp != NULL)
    {
      if (readfile(otmp, NULL, line2, (linenr_T)0, (linenr_T)MAXLNUM,
                   eap, READ_FILTER) != OK)
      {
#if defined(FEAT_EVAL)
        if (!aborting())
#endif
        {
          msg_putchar('\n');
          semsg(_(e_notread), otmp);
        }
        goto error;
      }
      if (curbuf != old_curbuf)
        goto filterend;
    }

    read_linecount = curbuf->b_ml.ml_line_count - read_linecount;

    if (shell_flags & SHELL_READ)
    {
      curbuf->b_op_start.lnum = line2 + 1;
      curbuf->b_op_end.lnum = curwin->w_cursor.lnum;
      appended_lines_mark(line2, read_linecount);
    }

    if (do_in)
    {
      if (cmdmod.keepmarks || vim_strchr(p_cpo, CPO_REMMARK) == NULL)
      {
        if (read_linecount >= linecount)
          /* move all marks from old lines to new lines */
          mark_adjust(line1, line2, linecount, 0L);
        else
        {
          /* move marks from old lines to new lines, delete marks
		     * that are in deleted lines */
          mark_adjust(line1, line1 + read_linecount - 1,
                      linecount, 0L);
          mark_adjust(line1 + read_linecount, line2, MAXLNUM, 0L);
        }
      }

      /*
	     * Put cursor on first filtered line for ":range!cmd".
	     * Adjust '[ and '] (set by buf_write()).
	     */
      curwin->w_cursor.lnum = line1;
      del_lines(linecount, TRUE);
      curbuf->b_op_start.lnum -= linecount; /* adjust '[ */
      curbuf->b_op_end.lnum -= linecount;   /* adjust '] */
      write_lnum_adjust(-linecount);        /* adjust last line
							   for next write */
#ifdef FEAT_FOLDING
      foldUpdate(curwin, curbuf->b_op_start.lnum, curbuf->b_op_end.lnum);
#endif
    }
    else
    {
      /*
	     * Put cursor on last new line for ":r !cmd".
	     */
      linecount = curbuf->b_op_end.lnum - curbuf->b_op_start.lnum + 1;
      curwin->w_cursor.lnum = curbuf->b_op_end.lnum;
    }

    beginline(BL_WHITE | BL_FIX); /* cursor on first non-blank */
    --no_wait_return;

    if (linecount > p_report)
    {
      if (do_in)
      {
        vim_snprintf(msg_buf, sizeof(msg_buf),
                     _("%ld lines filtered"), (long)linecount);
        if (msg(msg_buf) && !msg_scroll)
          /* save message to display it after redraw */
          set_keep_msg((char_u *)msg_buf, 0);
      }
      else
        msgmore((long)linecount);
    }
  }
  else
  {
  error:
    /* put cursor back in same position for ":w !cmd" */
    curwin->w_cursor = cursor_save;
    --no_wait_return;
    wait_return(FALSE);
  }

filterend:

  if (curbuf != old_curbuf)
  {
    --no_wait_return;
    emsg(_("E135: *Filter* Autocommands must not change current buffer"));
  }
  if (itmp != NULL)
    mch_remove(itmp);
  if (otmp != NULL)
    mch_remove(otmp);
  vim_free(itmp);
  vim_free(otmp);
}

/*
 * Call a shell to execute a command.
 * When "cmd" is NULL start an interactive shell.
 */
void do_shell(
    char_u *cmd,
    int flags) /* may be SHELL_DOOUT when output is redirected */
{
  buf_T *buf;
  int save_nwr;
#ifdef MSWIN
  int winstart = FALSE;
  int keep_termcap = FALSE;
#endif

  /*
     * Disallow shell commands for "rvim".
     * Disallow shell commands from .exrc and .vimrc in current directory for
     * security reasons.
     */
  if (check_restricted() || check_secure())
  {
    msg_end();
    return;
  }

#ifdef MSWIN
  /*
     * Check if ":!start" is used.  This implies not stopping termcap mode.
     */
  if (cmd != NULL)
    keep_termcap = winstart = (STRNICMP(cmd, "start ", 6) == 0);

#endif

  /*
     * For autocommands we want to get the output on the current screen, to
     * avoid having to type return below.
     */
  msg_putchar('\r'); // put cursor at start of line
  if (!autocmd_busy)
  {
#ifdef MSWIN
    if (!keep_termcap)
#endif
      stoptermcap();
  }
#ifdef MSWIN
  if (!winstart)
#endif
    msg_putchar('\n'); // may shift screen one line up

  // warning message before calling the shell
  if (p_warn && !autocmd_busy && msg_silent == 0)
    FOR_ALL_BUFFERS(buf)
  if (bufIsChangedNotTerm(buf))
  {
    msg_puts(_("[No write since last change]\n"));
    break;
  }

  // This windgoto is required for when the '\n' resulted in a "delete line
  // 1" command to the terminal.
  if (!swapping_screen())
    windgoto(msg_row, msg_col);
  cursor_on();
  (void)call_shell(cmd, SHELL_COOKED | flags);
  did_check_timestamps = FALSE;
  need_check_timestamps = TRUE;

  /*
     * put the message cursor at the end of the screen, avoids wait_return()
     * to overwrite the text that the external command showed
     */
  if (!swapping_screen())
  {
    msg_row = Rows - 1;
    msg_col = 0;
  }

  if (autocmd_busy)
  {
    if (msg_silent == 0)
      redraw_later_clear();
  }
  else
  {
    if (cmd == NULL
#ifdef MSWIN
        || (keep_termcap && !need_wait_return)
#endif
    )
    {
      if (msg_silent == 0)
        redraw_later_clear();
      need_wait_return = FALSE;
    }
    else
    {
      /*
       * If we switch screens when starttermcap() is called, we
       * really want to wait for "hit return to continue".
       */
      save_nwr = no_wait_return;
      if (swapping_screen())
        no_wait_return = FALSE;
      wait_return(msg_silent == 0);
      no_wait_return = save_nwr;
    }

#ifdef MSWIN
    if (!keep_termcap) // if keep_termcap is TRUE didn't stop termcap
#endif
      starttermcap(); // start termcap if not done by wait_return()
  }

  apply_autocmds(EVENT_SHELLCMDPOST, NULL, NULL, FALSE, curbuf);
}

#if !defined(UNIX)
static char_u *
find_pipe(char_u *cmd)
{
  char_u *p;
  int inquote = FALSE;

  for (p = cmd; *p != NUL; ++p)
  {
    if (!inquote && *p == '|')
      return p;
    if (*p == '"')
      inquote = !inquote;
    else if (rem_backslash(p))
      ++p;
  }
  return NULL;
}
#endif

/*
 * Create a shell command from a command string, input redirection file and
 * output redirection file.
 * Returns an allocated string with the shell command, or NULL for failure.
 */
char_u *
make_filter_cmd(
    char_u *cmd,  /* command */
    char_u *itmp, /* NULL or name of input file */
    char_u *otmp) /* NULL or name of output file */
{
  char_u *buf;
  long_u len;

#if defined(UNIX)
  int is_fish_shell;
  char_u *shell_name = get_isolated_shell_name();

  /* Account for fish's different syntax for subshells */
  is_fish_shell = (fnamecmp(shell_name, "fish") == 0);
  vim_free(shell_name);
  if (is_fish_shell)
    len = (long_u)STRLEN(cmd) + 13; /* "begin; " + "; end" + NUL */
  else
#endif
    len = (long_u)STRLEN(cmd) + 3; /* "()" + NUL */
  if (itmp != NULL)
    len += (long_u)STRLEN(itmp) + 9; /* " { < " + " } " */
  if (otmp != NULL)
    len += (long_u)STRLEN(otmp) + (long_u)STRLEN(p_srr) + 2; /* "  " */
  buf = alloc(len);
  if (buf == NULL)
    return NULL;

#if defined(UNIX)
  /*
     * Put braces around the command (for concatenated commands) when
     * redirecting input and/or output.
     */
  if (itmp != NULL || otmp != NULL)
  {
    if (is_fish_shell)
      vim_snprintf((char *)buf, len, "begin; %s; end", (char *)cmd);
    else
      vim_snprintf((char *)buf, len, "(%s)", (char *)cmd);
  }
  else
    STRCPY(buf, cmd);
  if (itmp != NULL)
  {
    STRCAT(buf, " < ");
    STRCAT(buf, itmp);
  }
#else
  /*
     * For shells that don't understand braces around commands, at least allow
     * the use of commands in a pipe.
     */
  STRCPY(buf, cmd);
  if (itmp != NULL)
  {
    char_u *p;

    /*
	 * If there is a pipe, we have to put the '<' in front of it.
	 * Don't do this when 'shellquote' is not empty, otherwise the
	 * redirection would be inside the quotes.
	 */
    if (*p_shq == NUL)
    {
      p = find_pipe(buf);
      if (p != NULL)
        *p = NUL;
    }
    STRCAT(buf, " <"); /* " < " causes problems on Amiga */
    STRCAT(buf, itmp);
    if (*p_shq == NUL)
    {
      p = find_pipe(cmd);
      if (p != NULL)
      {
        STRCAT(buf, " "); /* insert a space before the '|' for DOS */
        STRCAT(buf, p);
      }
    }
  }
#endif
  if (otmp != NULL)
    append_redir(buf, (int)len, p_srr, otmp);

  return buf;
}

/*
 * Append output redirection for file "fname" to the end of string buffer
 * "buf[buflen]"
 * Works with the 'shellredir' and 'shellpipe' options.
 * The caller should make sure that there is enough room:
 *	STRLEN(opt) + STRLEN(fname) + 3
 */
void append_redir(
    char_u *buf,
    int buflen,
    char_u *opt,
    char_u *fname)
{
  char_u *p;
  char_u *end;

  end = buf + STRLEN(buf);
  /* find "%s" */
  for (p = opt; (p = vim_strchr(p, '%')) != NULL; ++p)
  {
    if (p[1] == 's') /* found %s */
      break;
    if (p[1] == '%') /* skip %% */
      ++p;
  }
  if (p != NULL)
  {
    *end = ' '; /* not really needed? Not with sh, ksh or bash */
    vim_snprintf((char *)end + 1, (size_t)(buflen - (end + 1 - buf)),
                 (char *)opt, (char *)fname);
  }
  else
    vim_snprintf((char *)end, (size_t)(buflen - (end - buf)),
#ifdef FEAT_QUICKFIX
                 " %s %s",
#else
                 " %s%s", /* " > %s" causes problems on Amiga */
#endif
                 (char *)opt, (char *)fname);
}

#if defined(FEAT_VIMINFO) || defined(PROTO)

static int read_viminfo_barline(vir_T *virp, int got_encoding, int force, int writing);
static void write_viminfo_version(FILE *fp_out);
static void write_viminfo_barlines(vir_T *virp, FILE *fp_out);
static int viminfo_errcnt;

static int
no_viminfo(void)
{
  /* "vim -i NONE" does not read or write a viminfo file */
  return STRCMP(p_viminfofile, "NONE") == 0;
}

/*
 * Report an error for reading a viminfo file.
 * Count the number of errors.	When there are more than 10, return TRUE.
 */
int viminfo_error(char *errnum, char *message, char_u *line)
{
  vim_snprintf((char *)IObuff, IOSIZE, _("%sviminfo: %s in line: "),
               errnum, message);
  STRNCAT(IObuff, line, IOSIZE - STRLEN(IObuff) - 1);
  if (IObuff[STRLEN(IObuff) - 1] == '\n')
    IObuff[STRLEN(IObuff) - 1] = NUL;
  emsg((char *)IObuff);
  if (++viminfo_errcnt >= 10)
  {
    emsg(_("E136: viminfo: Too many errors, skipping rest of file"));
    return TRUE;
  }
  return FALSE;
}

/*
 * read_viminfo() -- Read the viminfo file.  Registers etc. which are already
 * set are not over-written unless "flags" includes VIF_FORCEIT. -- webb
 */
int read_viminfo(
    char_u *file, /* file name or NULL to use default name */
    int flags)    /* VIF_WANT_INFO et al. */
{
  FILE *fp;
  char_u *fname;

  if (no_viminfo())
    return FAIL;

  fname = viminfo_filename(file); /* get file name in allocated buffer */
  if (fname == NULL)
    return FAIL;
  fp = mch_fopen((char *)fname, READBIN);

  if (p_verbose > 0)
  {
    verbose_enter();
    smsg(_("Reading viminfo file \"%s\"%s%s%s"),
         fname,
         (flags & VIF_WANT_INFO) ? _(" info") : "",
         (flags & VIF_WANT_MARKS) ? _(" marks") : "",
         (flags & VIF_GET_OLDFILES) ? _(" oldfiles") : "",
         fp == NULL ? _(" FAILED") : "");
    verbose_leave();
  }

  vim_free(fname);
  if (fp == NULL)
    return FAIL;

  viminfo_errcnt = 0;
  do_viminfo(fp, NULL, flags);

  fclose(fp);
  return OK;
}

/*
 * Write the viminfo file.  The old one is read in first so that effectively a
 * merge of current info and old info is done.  This allows multiple vims to
 * run simultaneously, without losing any marks etc.
 * If "forceit" is TRUE, then the old file is not read in, and only internal
 * info is written to the file.
 */
void write_viminfo(char_u *file, int forceit)
{
  char_u *fname;
  FILE *fp_in = NULL;      /* input viminfo file, if any */
  FILE *fp_out = NULL;     /* output viminfo file */
  char_u *tempname = NULL; /* name of temp viminfo file */
  stat_T st_new;           /* mch_stat() of potential new file */
#if defined(UNIX) || defined(VMS)
  mode_t umask_save;
#endif
#ifdef UNIX
  int shortname = FALSE; /* use 8.3 file name */
  stat_T st_old;         /* mch_stat() of existing viminfo file */
#endif
#ifdef MSWIN
  int hidden = FALSE;
#endif

  if (no_viminfo())
    return;

  fname = viminfo_filename(file); /* may set to default if NULL */
  if (fname == NULL)
    return;

  fp_in = mch_fopen((char *)fname, READBIN);
  if (fp_in == NULL)
  {
    int fd;

    /* if it does exist, but we can't read it, don't try writing */
    if (mch_stat((char *)fname, &st_new) == 0)
      goto end;

    /* Create the new .viminfo non-accessible for others, because it may
	 * contain text from non-accessible documents. It is up to the user to
	 * widen access (e.g. to a group). This may also fail if there is a
	 * race condition, then just give up. */
    fd = mch_open((char *)fname,
                  O_CREAT | O_EXTRA | O_EXCL | O_WRONLY | O_NOFOLLOW, 0600);
    if (fd < 0)
      goto end;
    fp_out = fdopen(fd, WRITEBIN);
  }
  else
  {
    /*
	 * There is an existing viminfo file.  Create a temporary file to
	 * write the new viminfo into, in the same directory as the
	 * existing viminfo file, which will be renamed once all writing is
	 * successful.
	 */
#ifdef UNIX
    /*
	 * For Unix we check the owner of the file.  It's not very nice to
	 * overwrite a user's viminfo file after a "su root", with a
	 * viminfo file that the user can't read.
	 */
    st_old.st_dev = (dev_t)0;
    st_old.st_ino = 0;
    st_old.st_mode = 0600;
    if (mch_stat((char *)fname, &st_old) == 0 && getuid() != ROOT_UID && !(st_old.st_uid == getuid() ? (st_old.st_mode & 0200) : (st_old.st_gid == getgid() ? (st_old.st_mode & 0020) : (st_old.st_mode & 0002))))
    {
      int tt = msg_didany;

      /* avoid a wait_return for this message, it's annoying */
      semsg(_("E137: Viminfo file is not writable: %s"), fname);
      msg_didany = tt;
      fclose(fp_in);
      goto end;
    }
#endif
#ifdef MSWIN
    /* Get the file attributes of the existing viminfo file. */
    hidden = mch_ishidden(fname);
#endif

    /*
	 * Make tempname, find one that does not exist yet.
	 * Beware of a race condition: If someone logs out and all Vim
	 * instances exit at the same time a temp file might be created between
	 * stat() and open().  Use mch_open() with O_EXCL to avoid that.
	 * May try twice: Once normal and once with shortname set, just in
	 * case somebody puts his viminfo file in an 8.3 filesystem.
	 */
    for (;;)
    {
      int next_char = 'z';
      char_u *wp;

      tempname = buf_modname(
#ifdef UNIX
          shortname,
#else
          FALSE,
#endif
          fname,
#ifdef VMS
          (char_u *)"-tmp",
#else
          (char_u *)".tmp",
#endif
          FALSE);
      if (tempname == NULL) /* out of memory */
        break;

      /*
	     * Try a series of names.  Change one character, just before
	     * the extension.  This should also work for an 8.3
	     * file name, when after adding the extension it still is
	     * the same file as the original.
	     */
      wp = tempname + STRLEN(tempname) - 5;
      if (wp < gettail(tempname)) /* empty file name? */
        wp = gettail(tempname);
      for (;;)
      {
        /*
		 * Check if tempfile already exists.  Never overwrite an
		 * existing file!
		 */
        if (mch_stat((char *)tempname, &st_new) == 0)
        {
#ifdef UNIX
          /*
		     * Check if tempfile is same as original file.  May happen
		     * when modname() gave the same file back.  E.g.  silly
		     * link, or file name-length reached.  Try again with
		     * shortname set.
		     */
          if (!shortname && st_new.st_dev == st_old.st_dev && st_new.st_ino == st_old.st_ino)
          {
            VIM_CLEAR(tempname);
            shortname = TRUE;
            break;
          }
#endif
        }
        else
        {
          /* Try creating the file exclusively.  This may fail if
		     * another Vim tries to do it at the same time. */
#ifdef VMS
          /* fdopen() fails for some reason */
          umask_save = umask(077);
          fp_out = mch_fopen((char *)tempname, WRITEBIN);
          (void)umask(umask_save);
#else
          int fd;

          /* Use mch_open() to be able to use O_NOFOLLOW and set file
		     * protection:
		     * Unix: same as original file, but strip s-bit.  Reset
		     * umask to avoid it getting in the way.
		     * Others: r&w for user only. */
#ifdef UNIX
          umask_save = umask(0);
          fd = mch_open((char *)tempname,
                        O_CREAT | O_EXTRA | O_EXCL | O_WRONLY | O_NOFOLLOW,
                        (int)((st_old.st_mode & 0777) | 0600));
          (void)umask(umask_save);
#else
          fd = mch_open((char *)tempname,
                        O_CREAT | O_EXTRA | O_EXCL | O_WRONLY | O_NOFOLLOW, 0600);
#endif
          if (fd < 0)
          {
            fp_out = NULL;
#ifdef EEXIST
            /* Avoid trying lots of names while the problem is lack
			 * of permission, only retry if the file already
			 * exists. */
            if (errno != EEXIST)
              break;
#endif
          }
          else
            fp_out = fdopen(fd, WRITEBIN);
#endif /* VMS */
          if (fp_out != NULL)
            break;
        }

        /* Assume file exists, try again with another name. */
        if (next_char == 'a' - 1)
        {
          /* They all exist?  Must be something wrong! Don't write
		     * the viminfo file then. */
          semsg(_("E929: Too many viminfo temp files, like %s!"),
                tempname);
          break;
        }
        *wp = next_char;
        --next_char;
      }

      if (tempname != NULL)
        break;
      /* continue if shortname was set */
    }

#if defined(UNIX) && defined(HAVE_FCHOWN)
    if (tempname != NULL && fp_out != NULL)
    {
      stat_T tmp_st;

      /*
	     * Make sure the original owner can read/write the tempfile and
	     * otherwise preserve permissions, making sure the group matches.
	     */
      if (mch_stat((char *)tempname, &tmp_st) >= 0)
      {
        if (st_old.st_uid != tmp_st.st_uid)
          /* Changing the owner might fail, in which case the
		     * file will now owned by the current user, oh well. */
          vim_ignored = fchown(fileno(fp_out), st_old.st_uid, -1);
        if (st_old.st_gid != tmp_st.st_gid && fchown(fileno(fp_out), -1, st_old.st_gid) == -1)
          /* can't set the group to what it should be, remove
		     * group permissions */
          (void)mch_setperm(tempname, 0600);
      }
      else
        /* can't stat the file, set conservative permissions */
        (void)mch_setperm(tempname, 0600);
    }
#endif
  }

  /*
     * Check if the new viminfo file can be written to.
     */
  if (fp_out == NULL)
  {
    semsg(_("E138: Can't write viminfo file %s!"),
          (fp_in == NULL || tempname == NULL) ? fname : tempname);
    if (fp_in != NULL)
      fclose(fp_in);
    goto end;
  }

  if (p_verbose > 0)
  {
    verbose_enter();
    smsg(_("Writing viminfo file \"%s\""), fname);
    verbose_leave();
  }

  viminfo_errcnt = 0;
  do_viminfo(fp_in, fp_out, forceit ? 0 : (VIF_WANT_INFO | VIF_WANT_MARKS));

  if (fclose(fp_out) == EOF)
    ++viminfo_errcnt;

  if (fp_in != NULL)
  {
    fclose(fp_in);

    /* In case of an error keep the original viminfo file.  Otherwise
	 * rename the newly written file.  Give an error if that fails. */
    if (viminfo_errcnt == 0)
    {
      if (vim_rename(tempname, fname) == -1)
      {
        ++viminfo_errcnt;
        semsg(_("E886: Can't rename viminfo file to %s!"), fname);
      }
#ifdef MSWIN
      /* If the viminfo file was hidden then also hide the new file. */
      else if (hidden)
        mch_hide(fname);
#endif
    }
    if (viminfo_errcnt > 0)
      mch_remove(tempname);
  }

end:
  vim_free(fname);
  vim_free(tempname);
}

/*
 * Get the viminfo file name to use.
 * If "file" is given and not empty, use it (has already been expanded by
 * cmdline functions).
 * Otherwise use "-i file_name", value from 'viminfo' or the default, and
 * expand environment variables.
 * Returns an allocated string.  NULL when out of memory.
 */
static char_u *
viminfo_filename(char_u *file)
{
  if (file == NULL || *file == NUL)
  {
    if (*p_viminfofile != NUL)
      file = p_viminfofile;
    else if ((file = find_viminfo_parameter('n')) == NULL || *file == NUL)
    {
#ifdef VIMINFO_FILE2
#ifdef VMS
      if (mch_getenv((char_u *)"SYS$LOGIN") == NULL)
#else
#ifdef MSWIN
      /* Use $VIM only if $HOME is the default "C:/". */
      if (STRCMP(vim_getenv((char_u *)"HOME", NULL), "C:/") == 0 && mch_getenv((char_u *)"HOME") == NULL)
#else
      if (mch_getenv((char_u *)"HOME") == NULL)
#endif
#endif
      {
        /* don't use $VIM when not available. */
        expand_env((char_u *)"$VIM", NameBuff, MAXPATHL);
        if (STRCMP("$VIM", NameBuff) != 0) /* $VIM was expanded */
          file = (char_u *)VIMINFO_FILE2;
        else
          file = (char_u *)VIMINFO_FILE;
      }
      else
#endif
        file = (char_u *)VIMINFO_FILE;
    }
    expand_env(file, NameBuff, MAXPATHL);
    file = NameBuff;
  }
  return vim_strsave(file);
}

/*
 * do_viminfo() -- Should only be called from read_viminfo() & write_viminfo().
 */
static void
do_viminfo(FILE *fp_in, FILE *fp_out, int flags)
{
  int eof = FALSE;
  vir_T vir;
  int merge = FALSE;
  int do_copy_marks = FALSE;
  garray_T buflist;

  if ((vir.vir_line = alloc(LSIZE)) == NULL)
    return;
  vir.vir_fd = fp_in;
  vir.vir_conv.vc_type = CONV_NONE;
  ga_init2(&vir.vir_barlines, (int)sizeof(char_u *), 100);
  vir.vir_version = -1;

  if (fp_in != NULL)
  {
    if (flags & VIF_WANT_INFO)
    {
      if (fp_out != NULL)
      {
        /* Registers and marks are read and kept separate from what
		 * this Vim is using.  They are merged when writing. */
        prepare_viminfo_registers();
        prepare_viminfo_marks();
      }

      eof = read_viminfo_up_to_marks(&vir,
                                     flags & VIF_FORCEIT, fp_out != NULL);
      merge = TRUE;
    }
    else if (flags != 0)
      /* Skip info, find start of marks */
      while (!(eof = viminfo_readline(&vir)) && vir.vir_line[0] != '>')
        ;

    do_copy_marks = (flags &
                     (VIF_WANT_MARKS | VIF_GET_OLDFILES | VIF_FORCEIT));
  }

  if (fp_out != NULL)
  {
    /* Write the info: */
    fprintf(fp_out, _("# This viminfo file was generated by Vim %s.\n"),
            VIM_VERSION_MEDIUM);
    fputs(_("# You may edit it if you're careful!\n\n"), fp_out);
    write_viminfo_version(fp_out);
    fputs(_("# Value of 'encoding' when this file was written\n"), fp_out);
    fprintf(fp_out, "*encoding=%s\n\n", p_enc);
    write_viminfo_search_pattern(fp_out);
    write_viminfo_sub_string(fp_out);
#ifdef FEAT_CMDHIST
    write_viminfo_history(fp_out, merge);
#endif
    write_viminfo_registers(fp_out);
    finish_viminfo_registers();
#ifdef FEAT_EVAL
    write_viminfo_varlist(fp_out);
#endif
    write_viminfo_filemarks(fp_out);
    finish_viminfo_marks();
    write_viminfo_bufferlist(fp_out);
    write_viminfo_barlines(&vir, fp_out);

    if (do_copy_marks)
      ga_init2(&buflist, sizeof(buf_T *), 50);
    write_viminfo_marks(fp_out, do_copy_marks ? &buflist : NULL);
  }

  if (do_copy_marks)
  {
    copy_viminfo_marks(&vir, fp_out, &buflist, eof, flags);
    if (fp_out != NULL)
      ga_clear(&buflist);
  }

  vim_free(vir.vir_line);
  if (vir.vir_conv.vc_type != CONV_NONE)
    convert_setup(&vir.vir_conv, NULL, NULL);
  ga_clear_strings(&vir.vir_barlines);
}

/*
 * read_viminfo_up_to_marks() -- Only called from do_viminfo().  Reads in the
 * first part of the viminfo file which contains everything but the marks that
 * are local to a file.  Returns TRUE when end-of-file is reached. -- webb
 */
static int
read_viminfo_up_to_marks(
    vir_T *virp,
    int forceit,
    int writing)
{
  int eof;
  buf_T *buf;
  int got_encoding = FALSE;

#ifdef FEAT_CMDHIST
  prepare_viminfo_history(forceit ? 9999 : 0, writing);
#endif

  eof = viminfo_readline(virp);
  while (!eof && virp->vir_line[0] != '>')
  {
    switch (virp->vir_line[0])
    {
      /* Characters reserved for future expansion, ignored now */
    case '+': /* "+40 /path/dir file", for running vim without args */
    case '^': /* to be defined */
    case '<': /* long line - ignored */
              /* A comment or empty line. */
    case NUL:
    case '\r':
    case '\n':
    case '#':
      eof = viminfo_readline(virp);
      break;
    case '|':
      eof = read_viminfo_barline(virp, got_encoding,
                                 forceit, writing);
      break;
    case '*': /* "*encoding=value" */
      got_encoding = TRUE;
      eof = viminfo_encoding(virp);
      break;
    case '!': /* global variable */
#ifdef FEAT_EVAL
      eof = read_viminfo_varlist(virp, writing);
#else
      eof = viminfo_readline(virp);
#endif
      break;
    case '%': /* entry for buffer list */
      eof = read_viminfo_bufferlist(virp, writing);
      break;
    case '"':
      /* When registers are in bar lines skip the old style register
		 * lines. */
      if (virp->vir_version < VIMINFO_VERSION_WITH_REGISTERS)
        eof = read_viminfo_register(virp, forceit);
      else
        do
        {
          eof = viminfo_readline(virp);
        } while (!eof && (virp->vir_line[0] == TAB || virp->vir_line[0] == '<'));
      break;
    case '/': /* Search string */
    case '&': /* Substitute search string */
    case '~': /* Last search string, followed by '/' or '&' */
      eof = read_viminfo_search_pattern(virp, forceit);
      break;
    case '$':
      eof = read_viminfo_sub_string(virp, forceit);
      break;
    case ':':
    case '?':
    case '=':
    case '@':
#ifdef FEAT_CMDHIST
      /* When history is in bar lines skip the old style history
		 * lines. */
      if (virp->vir_version < VIMINFO_VERSION_WITH_HISTORY)
        eof = read_viminfo_history(virp, writing);
      else
#endif
        eof = viminfo_readline(virp);
      break;
    case '-':
    case '\'':
      /* When file marks are in bar lines skip the old style lines. */
      if (virp->vir_version < VIMINFO_VERSION_WITH_MARKS)
        eof = read_viminfo_filemark(virp, forceit);
      else
        eof = viminfo_readline(virp);
      break;
    default:
      if (viminfo_error("E575: ", _("Illegal starting char"),
                        virp->vir_line))
        eof = TRUE;
      else
        eof = viminfo_readline(virp);
      break;
    }
  }

#ifdef FEAT_CMDHIST
  /* Finish reading history items. */
  if (!writing)
    finish_viminfo_history(virp);
#endif

  /* Change file names to buffer numbers for fmarks. */
  FOR_ALL_BUFFERS(buf)
  fmarks_check_names(buf);

  return eof;
}

/*
 * Compare the 'encoding' value in the viminfo file with the current value of
 * 'encoding'.  If different and the 'c' flag is in 'viminfo', setup for
 * conversion of text with iconv() in viminfo_readstring().
 */
static int
viminfo_encoding(vir_T *virp)
{
  char_u *p;
  int i;

  if (get_viminfo_parameter('c') != 0)
  {
    p = vim_strchr(virp->vir_line, '=');
    if (p != NULL)
    {
      /* remove trailing newline */
      ++p;
      for (i = 0; vim_isprintc(p[i]); ++i)
        ;
      p[i] = NUL;

      convert_setup(&virp->vir_conv, p, p_enc);
    }
  }
  return viminfo_readline(virp);
}

/*
 * Read a line from the viminfo file.
 * Returns TRUE for end-of-file;
 */
int viminfo_readline(vir_T *virp)
{
  return vim_fgets(virp->vir_line, LSIZE, virp->vir_fd);
}

/*
 * Check string read from viminfo file.
 * Remove '\n' at the end of the line.
 * - replace CTRL-V CTRL-V with CTRL-V
 * - replace CTRL-V 'n'    with '\n'
 *
 * Check for a long line as written by viminfo_writestring().
 *
 * Return the string in allocated memory (NULL when out of memory).
 */
char_u *
viminfo_readstring(
    vir_T *virp,
    int off,            /* offset for virp->vir_line */
    int convert UNUSED) /* convert the string */
{
  char_u *retval;
  char_u *s, *d;
  long len;

  if (virp->vir_line[off] == Ctrl_V && vim_isdigit(virp->vir_line[off + 1]))
  {
    len = atol((char *)virp->vir_line + off + 1);
    retval = alloc(len);
    if (retval == NULL)
    {
      /* Line too long?  File messed up?  Skip next line. */
      (void)vim_fgets(virp->vir_line, 10, virp->vir_fd);
      return NULL;
    }
    (void)vim_fgets(retval, (int)len, virp->vir_fd);
    s = retval + 1; /* Skip the leading '<' */
  }
  else
  {
    retval = vim_strsave(virp->vir_line + off);
    if (retval == NULL)
      return NULL;
    s = retval;
  }

  /* Change CTRL-V CTRL-V to CTRL-V and CTRL-V n to \n in-place. */
  d = retval;
  while (*s != NUL && *s != '\n')
  {
    if (s[0] == Ctrl_V && s[1] != NUL)
    {
      if (s[1] == 'n')
        *d++ = '\n';
      else
        *d++ = Ctrl_V;
      s += 2;
    }
    else
      *d++ = *s++;
  }
  *d = NUL;

  if (convert && virp->vir_conv.vc_type != CONV_NONE && *retval != NUL)
  {
    d = string_convert(&virp->vir_conv, retval, NULL);
    if (d != NULL)
    {
      vim_free(retval);
      retval = d;
    }
  }

  return retval;
}

/*
 * write string to viminfo file
 * - replace CTRL-V with CTRL-V CTRL-V
 * - replace '\n'   with CTRL-V 'n'
 * - add a '\n' at the end
 *
 * For a long line:
 * - write " CTRL-V <length> \n " in first line
 * - write " < <string> \n "	  in second line
 */
void viminfo_writestring(FILE *fd, char_u *p)
{
  int c;
  char_u *s;
  int len = 0;

  for (s = p; *s != NUL; ++s)
  {
    if (*s == Ctrl_V || *s == '\n')
      ++len;
    ++len;
  }

  /* If the string will be too long, write its length and put it in the next
     * line.  Take into account that some room is needed for what comes before
     * the string (e.g., variable name).  Add something to the length for the
     * '<', NL and trailing NUL. */
  if (len > LSIZE / 2)
    fprintf(fd, IF_EB("\026%d\n<", CTRL_V_STR "%d\n<"), len + 3);

  while ((c = *p++) != NUL)
  {
    if (c == Ctrl_V || c == '\n')
    {
      putc(Ctrl_V, fd);
      if (c == '\n')
        c = 'n';
    }
    putc(c, fd);
  }
  putc('\n', fd);
}

/*
 * Write a string in quotes that barline_parse() can read back.
 * Breaks the line in less than LSIZE pieces when needed.
 * Returns remaining characters in the line.
 */
int barline_writestring(FILE *fd, char_u *s, int remaining_start)
{
  char_u *p;
  int remaining = remaining_start;
  int len = 2;

  /* Count the number of characters produced, including quotes. */
  for (p = s; *p != NUL; ++p)
  {
    if (*p == NL)
      len += 2;
    else if (*p == '"' || *p == '\\')
      len += 2;
    else
      ++len;
  }
  if (len > remaining - 2)
  {
    fprintf(fd, ">%d\n|<", len);
    remaining = LSIZE - 20;
  }

  putc('"', fd);
  for (p = s; *p != NUL; ++p)
  {
    if (*p == NL)
    {
      putc('\\', fd);
      putc('n', fd);
      --remaining;
    }
    else if (*p == '"' || *p == '\\')
    {
      putc('\\', fd);
      putc(*p, fd);
      --remaining;
    }
    else
      putc(*p, fd);
    --remaining;

    if (remaining < 3)
    {
      putc('\n', fd);
      putc('|', fd);
      putc('<', fd);
      /* Leave enough space for another continuation. */
      remaining = LSIZE - 20;
    }
  }
  putc('"', fd);
  return remaining - 2;
}

/*
 * Parse a viminfo line starting with '|'.
 * Add each decoded value to "values".
 * Returns TRUE if the next line is to be read after using the parsed values.
 */
static int
barline_parse(vir_T *virp, char_u *text, garray_T *values)
{
  char_u *p = text;
  char_u *nextp = NULL;
  char_u *buf = NULL;
  bval_T *value;
  int i;
  int allocated = FALSE;
  int eof;
  char_u *sconv;
  int converted;

  while (*p == ',')
  {
    ++p;
    if (ga_grow(values, 1) == FAIL)
      break;
    value = (bval_T *)(values->ga_data) + values->ga_len;

    if (*p == '>')
    {
      /* Need to read a continuation line.  Put strings in allocated
	     * memory, because virp->vir_line is overwritten. */
      if (!allocated)
      {
        for (i = 0; i < values->ga_len; ++i)
        {
          bval_T *vp = (bval_T *)(values->ga_data) + i;

          if (vp->bv_type == BVAL_STRING && !vp->bv_allocated)
          {
            vp->bv_string = vim_strnsave(vp->bv_string, vp->bv_len);
            vp->bv_allocated = TRUE;
          }
        }
        allocated = TRUE;
      }

      if (vim_isdigit(p[1]))
      {
        size_t len;
        size_t todo;
        size_t n;

        /* String value was split into lines that are each shorter
		 * than LSIZE:
		 *     |{bartype},>{length of "{text}{text2}"}
		 *     |<"{text1}
		 *     |<{text2}",{value}
		 * Length includes the quotes.
		 */
        ++p;
        len = getdigits(&p);
        buf = alloc(len + 1);
        if (buf == NULL)
          return TRUE;
        p = buf;
        for (todo = len; todo > 0; todo -= n)
        {
          eof = viminfo_readline(virp);
          if (eof || virp->vir_line[0] != '|' || virp->vir_line[1] != '<')
          {
            /* File was truncated or garbled. Read another line if
			 * this one starts with '|'. */
            vim_free(buf);
            return eof || virp->vir_line[0] == '|';
          }
          /* Get length of text, excluding |< and NL chars. */
          n = STRLEN(virp->vir_line);
          while (n > 0 && (virp->vir_line[n - 1] == NL || virp->vir_line[n - 1] == CAR))
            --n;
          n -= 2;
          if (n > todo)
          {
            /* more values follow after the string */
            nextp = virp->vir_line + 2 + todo;
            n = todo;
          }
          mch_memmove(p, virp->vir_line + 2, n);
          p += n;
        }
        *p = NUL;
        p = buf;
      }
      else
      {
        /* Line ending in ">" continues in the next line:
		 *     |{bartype},{lots of values},>
		 *     |<{value},{value}
		 */
        eof = viminfo_readline(virp);
        if (eof || virp->vir_line[0] != '|' || virp->vir_line[1] != '<')
          /* File was truncated or garbled. Read another line if
		     * this one starts with '|'. */
          return eof || virp->vir_line[0] == '|';
        p = virp->vir_line + 2;
      }
    }

    if (isdigit(*p))
    {
      value->bv_type = BVAL_NR;
      value->bv_nr = getdigits(&p);
      ++values->ga_len;
    }
    else if (*p == '"')
    {
      int len = 0;
      char_u *s = p;

      /* Unescape special characters in-place. */
      ++p;
      while (*p != '"')
      {
        if (*p == NL || *p == NUL)
          return TRUE; /* syntax error, drop the value */
        if (*p == '\\')
        {
          ++p;
          if (*p == 'n')
            s[len++] = '\n';
          else
            s[len++] = *p;
          ++p;
        }
        else
          s[len++] = *p++;
      }
      ++p;
      s[len] = NUL;

      converted = FALSE;
      if (virp->vir_conv.vc_type != CONV_NONE && *s != NUL)
      {
        sconv = string_convert(&virp->vir_conv, s, NULL);
        if (sconv != NULL)
        {
          if (s == buf)
            vim_free(s);
          s = sconv;
          buf = s;
          converted = TRUE;
        }
      }

      /* Need to copy in allocated memory if the string wasn't allocated
	     * above and we did allocate before, thus vir_line may change. */
      if (s != buf && allocated)
        s = vim_strsave(s);
      value->bv_string = s;
      value->bv_type = BVAL_STRING;
      value->bv_len = len;
      value->bv_allocated = allocated || converted;
      ++values->ga_len;
      if (nextp != NULL)
      {
        /* values following a long string */
        p = nextp;
        nextp = NULL;
      }
    }
    else if (*p == ',')
    {
      value->bv_type = BVAL_EMPTY;
      ++values->ga_len;
    }
    else
      break;
  }
  return TRUE;
}

static int
read_viminfo_barline(vir_T *virp, int got_encoding, int force, int writing)
{
  char_u *p = virp->vir_line + 1;
  int bartype;
  garray_T values;
  bval_T *vp;
  int i;
  int read_next = TRUE;

  /* The format is: |{bartype},{value},...
     * For a very long string:
     *     |{bartype},>{length of "{text}{text2}"}
     *     |<{text1}
     *     |<{text2},{value}
     * For a long line not using a string
     *     |{bartype},{lots of values},>
     *     |<{value},{value}
     */
  if (*p == '<')
  {
    /* Continuation line of an unrecognized item. */
    if (writing)
      ga_add_string(&virp->vir_barlines, virp->vir_line);
  }
  else
  {
    ga_init2(&values, sizeof(bval_T), 20);
    bartype = getdigits(&p);
    switch (bartype)
    {
    case BARTYPE_VERSION:
      /* Only use the version when it comes before the encoding.
		 * If it comes later it was copied by a Vim version that
		 * doesn't understand the version. */
      if (!got_encoding)
      {
        read_next = barline_parse(virp, p, &values);
        vp = (bval_T *)values.ga_data;
        if (values.ga_len > 0 && vp->bv_type == BVAL_NR)
          virp->vir_version = vp->bv_nr;
      }
      break;

    case BARTYPE_HISTORY:
      read_next = barline_parse(virp, p, &values);
      handle_viminfo_history(&values, writing);
      break;

    case BARTYPE_REGISTER:
      read_next = barline_parse(virp, p, &values);
      handle_viminfo_register(&values, force);
      break;

    case BARTYPE_MARK:
      read_next = barline_parse(virp, p, &values);
      handle_viminfo_mark(&values, force);
      break;

    default:
      /* copy unrecognized line (for future use) */
      if (writing)
        ga_add_string(&virp->vir_barlines, virp->vir_line);
    }
    for (i = 0; i < values.ga_len; ++i)
    {
      vp = (bval_T *)values.ga_data + i;
      if (vp->bv_type == BVAL_STRING && vp->bv_allocated)
        vim_free(vp->bv_string);
    }
    ga_clear(&values);
  }

  if (read_next)
    return viminfo_readline(virp);
  return FALSE;
}

static void
write_viminfo_version(FILE *fp_out)
{
  fprintf(fp_out, "# Viminfo version\n|%d,%d\n\n",
          BARTYPE_VERSION, VIMINFO_VERSION);
}

static void
write_viminfo_barlines(vir_T *virp, FILE *fp_out)
{
  int i;
  garray_T *gap = &virp->vir_barlines;
  int seen_useful = FALSE;
  char *line;

  if (gap->ga_len > 0)
  {
    fputs(_("\n# Bar lines, copied verbatim:\n"), fp_out);

    /* Skip over continuation lines until seeing a useful line. */
    for (i = 0; i < gap->ga_len; ++i)
    {
      line = ((char **)(gap->ga_data))[i];
      if (seen_useful || line[1] != '<')
      {
        fputs(line, fp_out);
        seen_useful = TRUE;
      }
    }
  }
}
#endif /* FEAT_VIMINFO */

/*
 * Return the current time in seconds.  Calls time(), unless test_settime()
 * was used.
 */
time_T
vim_time(void)
{
#ifdef FEAT_EVAL
  return time_for_testing == 0 ? time(NULL) : time_for_testing;
#else
  return time(NULL);
#endif
}

/*
 * Implementation of ":fixdel", also used by get_stty().
 *  <BS>    resulting <Del>
 *   ^?		^H
 * not ^?	^?
 */
void do_fixdel(exarg_T *eap UNUSED)
{
  char_u *p;

  p = find_termcode((char_u *)"kb");
  add_termcode((char_u *)"kD", p != NULL && *p == DEL ? (char_u *)CTRL_H_STR : DEL_STR, FALSE);
}

void print_line_no_prefix(
    linenr_T lnum,
    int use_number,
    int list)
{
  char numbuf[30];

  if (curwin->w_p_nu || use_number)
  {
    vim_snprintf(numbuf, sizeof(numbuf),
                 "%*ld ", number_width(curwin), (long)lnum);
    msg_puts_attr(numbuf, HL_ATTR(HLF_N)); /* Highlight line nrs */
  }
  msg_prt_line(ml_get(lnum), list);
}

/*
 * Print a text line.  Also in silent mode ("ex -s").
 */
void print_line(linenr_T lnum, int use_number, int list)
{
  int save_silent = silent_mode;

  /* apply :filter /pat/ */
  if (message_filtered(ml_get(lnum)))
    return;

  msg_start();
  silent_mode = FALSE;
  info_message = TRUE; /* use mch_msg(), not mch_errmsg() */
  print_line_no_prefix(lnum, use_number, list);
  if (save_silent)
  {
    msg_putchar('\n');
    cursor_on(); /* msg_start() switches it off */
    silent_mode = save_silent;
  }
  info_message = FALSE;
}

int rename_buffer(char_u *new_fname)
{
  char_u *fname, *sfname, *xfname;
  buf_T *buf;

  buf = curbuf;
  apply_autocmds(EVENT_BUFFILEPRE, NULL, NULL, FALSE, curbuf);
  /* buffer changed, don't change name now */
  if (buf != curbuf)
    return FAIL;
#ifdef FEAT_EVAL
  if (aborting()) /* autocmds may abort script processing */
    return FAIL;
#endif
  /*
     * The name of the current buffer will be changed.
     * A new (unlisted) buffer entry needs to be made to hold the old file
     * name, which will become the alternate file name.
     * But don't set the alternate file name if the buffer didn't have a
     * name.
     */
  fname = curbuf->b_ffname;
  sfname = curbuf->b_sfname;
  xfname = curbuf->b_fname;
  curbuf->b_ffname = NULL;
  curbuf->b_sfname = NULL;
  if (setfname(curbuf, new_fname, NULL, TRUE) == FAIL)
  {
    curbuf->b_ffname = fname;
    curbuf->b_sfname = sfname;
    return FAIL;
  }
  curbuf->b_flags |= BF_NOTEDITED;
  if (xfname != NULL && *xfname != NUL)
  {
    buf = buflist_new(fname, xfname, curwin->w_cursor.lnum, 0);
    if (buf != NULL && !cmdmod.keepalt)
      curwin->w_alt_fnum = buf->b_fnum;
  }
  vim_free(fname);
  vim_free(sfname);
  apply_autocmds(EVENT_BUFFILEPOST, NULL, NULL, FALSE, curbuf);

  /* Change directories when the 'acd' option is set. */
  DO_AUTOCHDIR;
  return OK;
}

/*
 * ":file[!] [fname]".
 */
void ex_file(exarg_T *eap)
{
  /* ":0file" removes the file name.  Check for illegal uses ":3file",
     * "0file name", etc. */
  if (eap->addr_count > 0 && (*eap->arg != NUL || eap->line2 > 0 || eap->addr_count > 1))
  {
    emsg(_(e_invarg));
    return;
  }

  if (*eap->arg != NUL || eap->addr_count == 1)
  {
    if (rename_buffer(eap->arg) == FAIL)
      return;
    redraw_tabline = TRUE;
  }

  // print file name if no argument or 'F' is not in 'shortmess'
  if (*eap->arg == NUL || !shortmess(SHM_FILEINFO))
    fileinfo(FALSE, FALSE, eap->forceit);
}

/*
 * ":update".
 */
void ex_update(exarg_T *eap)
{
  if (curbufIsChanged())
    (void)do_write(eap);
}

/*
 * ":write" and ":saveas".
 */
void ex_write(exarg_T *eap)
{
  if (eap->cmdidx == CMD_saveas)
  {
    // :saveas does not take a range, uses all lines.
    eap->line1 = 1;
    eap->line2 = curbuf->b_ml.ml_line_count;
  }

  if (eap->usefilter) /* input lines to shell command */
    do_bang(1, eap, FALSE, TRUE, FALSE);
  else
    (void)do_write(eap);
}

/*
 * write current buffer to file 'eap->arg'
 * if 'eap->append' is TRUE, append to the file
 *
 * if *eap->arg == NUL write to current file
 *
 * return FAIL for failure, OK otherwise
 */
int do_write(exarg_T *eap)
{
  int other;
  char_u *fname = NULL; /* init to shut up gcc */
  char_u *ffname;
  int retval = FAIL;
  char_u *free_fname = NULL;
#ifdef FEAT_BROWSE
  char_u *browse_file = NULL;
#endif
  buf_T *alt_buf = NULL;
  int name_was_missing;

  if (not_writing()) /* check 'write' option */
    return FAIL;

  ffname = eap->arg;
#ifdef FEAT_BROWSE
  if (cmdmod.browse)
  {
    browse_file = do_browse(BROWSE_SAVE, (char_u *)_("Save As"), ffname,
                            NULL, NULL, NULL, curbuf);
    if (browse_file == NULL)
      goto theend;
    ffname = browse_file;
  }
#endif
  if (*ffname == NUL)
  {
    if (eap->cmdidx == CMD_saveas)
    {
      emsg(_(e_argreq));
      goto theend;
    }
    other = FALSE;
  }
  else
  {
    fname = ffname;
    free_fname = fix_fname(ffname);
    /*
	 * When out-of-memory, keep unexpanded file name, because we MUST be
	 * able to write the file in this situation.
	 */
    if (free_fname != NULL)
      ffname = free_fname;
    other = otherfile(ffname);
  }

  /*
     * If we have a new file, put its name in the list of alternate file names.
     */
  if (other)
  {
    if (vim_strchr(p_cpo, CPO_ALTWRITE) != NULL || eap->cmdidx == CMD_saveas)
      alt_buf = setaltfname(ffname, fname, (linenr_T)1);
    else
      alt_buf = buflist_findname(ffname);
    if (alt_buf != NULL && alt_buf->b_ml.ml_mfp != NULL)
    {
      /* Overwriting a file that is loaded in another buffer is not a
	     * good idea. */
      emsg(_(e_bufloaded));
      goto theend;
    }
  }

  /*
     * Writing to the current file is not allowed in readonly mode
     * and a file name is required.
     * "nofile" and "nowrite" buffers cannot be written implicitly either.
     */
  if (!other && (
#ifdef FEAT_QUICKFIX
                    bt_dontwrite_msg(curbuf) ||
#endif
                    check_fname() == FAIL || check_readonly(&eap->forceit, curbuf)))
    goto theend;

  if (!other)
  {
    ffname = curbuf->b_ffname;
    fname = curbuf->b_fname;
    /*
	 * Not writing the whole file is only allowed with '!'.
	 */
    if ((eap->line1 != 1 || eap->line2 != curbuf->b_ml.ml_line_count) && !eap->forceit && !eap->append && !p_wa)
    {
      {
        emsg(_("E140: Use ! to write partial buffer"));
        goto theend;
      }
    }
  }

  if (check_overwrite(eap, curbuf, fname, ffname, other) == OK)
  {
    if (eap->cmdidx == CMD_saveas && alt_buf != NULL)
    {
      buf_T *was_curbuf = curbuf;

      apply_autocmds(EVENT_BUFFILEPRE, NULL, NULL, FALSE, curbuf);
      apply_autocmds(EVENT_BUFFILEPRE, NULL, NULL, FALSE, alt_buf);
#ifdef FEAT_EVAL
      if (curbuf != was_curbuf || aborting())
#else
      if (curbuf != was_curbuf)
#endif
      {
        /* buffer changed, don't change name now */
        retval = FAIL;
        goto theend;
      }
      /* Exchange the file names for the current and the alternate
	     * buffer.  This makes it look like we are now editing the buffer
	     * under the new name.  Must be done before buf_write(), because
	     * if there is no file name and 'cpo' contains 'F', it will set
	     * the file name. */
      fname = alt_buf->b_fname;
      alt_buf->b_fname = curbuf->b_fname;
      curbuf->b_fname = fname;
      fname = alt_buf->b_ffname;
      alt_buf->b_ffname = curbuf->b_ffname;
      curbuf->b_ffname = fname;
      fname = alt_buf->b_sfname;
      alt_buf->b_sfname = curbuf->b_sfname;
      curbuf->b_sfname = fname;
      buf_name_changed(curbuf);

      apply_autocmds(EVENT_BUFFILEPOST, NULL, NULL, FALSE, curbuf);
      apply_autocmds(EVENT_BUFFILEPOST, NULL, NULL, FALSE, alt_buf);
      if (!alt_buf->b_p_bl)
      {
        alt_buf->b_p_bl = TRUE;
        apply_autocmds(EVENT_BUFADD, NULL, NULL, FALSE, alt_buf);
      }
#ifdef FEAT_EVAL
      if (curbuf != was_curbuf || aborting())
#else
      if (curbuf != was_curbuf)
#endif
      {
        /* buffer changed, don't write the file */
        retval = FAIL;
        goto theend;
      }

      /* If 'filetype' was empty try detecting it now. */
      if (*curbuf->b_p_ft == NUL)
      {
        if (au_has_group((char_u *)"filetypedetect"))
          (void)do_doautocmd((char_u *)"filetypedetect BufRead",
                             TRUE, NULL);
        do_modelines(0);
      }

      /* Autocommands may have changed buffer names, esp. when
	     * 'autochdir' is set. */
      fname = curbuf->b_sfname;
    }

    name_was_missing = curbuf->b_ffname == NULL;

    retval = buf_write(curbuf, ffname, fname, eap->line1, eap->line2,
                       eap, eap->append, eap->forceit, TRUE, FALSE);

    /* After ":saveas fname" reset 'readonly'. */
    if (eap->cmdidx == CMD_saveas)
    {
      if (retval == OK)
      {
        curbuf->b_p_ro = FALSE;
        redraw_tabline = TRUE;
      }
    }

    /* Change directories when the 'acd' option is set and the file name
	 * got changed or set. */
    if (eap->cmdidx == CMD_saveas || name_was_missing)
      DO_AUTOCHDIR;
  }

theend:
#ifdef FEAT_BROWSE
  vim_free(browse_file);
#endif
  vim_free(free_fname);
  return retval;
}

/*
 * Check if it is allowed to overwrite a file.  If b_flags has BF_NOTEDITED,
 * BF_NEW or BF_READERR, check for overwriting current file.
 * May set eap->forceit if a dialog says it's OK to overwrite.
 * Return OK if it's OK, FAIL if it is not.
 */
int check_overwrite(
    exarg_T *eap,
    buf_T *buf,
    char_u *fname,  /* file name to be used (can differ from
			       buf->ffname) */
    char_u *ffname, /* full path version of fname */
    int other)      /* writing under other name */
{
  /*
     * write to other file or b_flags set or not writing the whole file:
     * overwriting only allowed with '!'
     */
  if ((other || (buf->b_flags & BF_NOTEDITED) || ((buf->b_flags & BF_NEW) && vim_strchr(p_cpo, CPO_OVERNEW) == NULL) || (buf->b_flags & BF_READERR)) && !p_wa
#ifdef FEAT_QUICKFIX
      && !bt_nofile(buf)
#endif
      && vim_fexists(ffname))
  {
    if (!eap->forceit && !eap->append)
    {
#ifdef UNIX
      /* with UNIX it is possible to open a directory */
      if (mch_isdir(ffname))
      {
        semsg(_(e_isadir2), ffname);
        return FAIL;
      }
#endif
      {
        emsg(_(e_exists));
        return FAIL;
      }
    }

    /* For ":w! filename" check that no swap file exists for "filename". */
    if (other && !emsg_silent)
    {
      char_u *dir;
      char_u *p;
      int r;
      char_u *swapname;

      /* We only try the first entry in 'directory', without checking if
	     * it's writable.  If the "." directory is not writable the write
	     * will probably fail anyway.
	     * Use 'shortname' of the current buffer, since there is no buffer
	     * for the written file. */
      if (*p_dir == NUL)
      {
        dir = alloc(5);
        if (dir == NULL)
          return FAIL;
        STRCPY(dir, ".");
      }
      else
      {
        dir = alloc(MAXPATHL);
        if (dir == NULL)
          return FAIL;
        p = p_dir;
        copy_option_part(&p, dir, MAXPATHL, ",");
      }
      swapname = makeswapname(fname, ffname, curbuf, dir);
      vim_free(dir);
      r = vim_fexists(swapname);
      if (r)
      {
        {
          semsg(_("E768: Swap file exists: %s (:silent! overrides)"),
                swapname);
          vim_free(swapname);
          return FAIL;
        }
      }
      vim_free(swapname);
    }
  }
  return OK;
}

/*
 * Handle ":wnext", ":wNext" and ":wprevious" commands.
 */
void ex_wnext(exarg_T *eap)
{
  int i;

  if (eap->cmd[1] == 'n')
    i = curwin->w_arg_idx + (int)eap->line2;
  else
    i = curwin->w_arg_idx - (int)eap->line2;
  eap->line1 = 1;
  eap->line2 = curbuf->b_ml.ml_line_count;
  if (do_write(eap) != FAIL)
    do_argfile(eap, i);
}

/*
 * ":wall", ":wqall" and ":xall": Write all changed files (and exit).
 */
void do_wqall(exarg_T *eap)
{
  buf_T *buf;
  int error = 0;
  int save_forceit = eap->forceit;

  if (eap->cmdidx == CMD_xall || eap->cmdidx == CMD_wqall)
    exiting = TRUE;

  FOR_ALL_BUFFERS(buf)
  {
#ifdef FEAT_TERMINAL
    if (exiting && term_job_running(buf->b_term))
    {
      no_write_message_nobang(buf);
      ++error;
    }
    else
#endif
        if (bufIsChanged(buf) && !bt_dontwrite(buf))
    {
      /*
	     * Check if there is a reason the buffer cannot be written:
	     * 1. if the 'write' option is set
	     * 2. if there is no file name (even after browsing)
	     * 3. if the 'readonly' is set (even after a dialog)
	     * 4. if overwriting is allowed (even after a dialog)
	     */
      if (not_writing())
      {
        ++error;
        break;
      }
#ifdef FEAT_BROWSE
      /* ":browse wall": ask for file name if there isn't one */
      if (buf->b_ffname == NULL && cmdmod.browse)
        browse_save_fname(buf);
#endif
      if (buf->b_ffname == NULL)
      {
        semsg(_("E141: No file name for buffer %ld"), (long)buf->b_fnum);
        ++error;
      }
      else if (check_readonly(&eap->forceit, buf) || check_overwrite(eap, buf, buf->b_fname, buf->b_ffname,
                                                                     FALSE) == FAIL)
      {
        ++error;
      }
      else
      {
        bufref_T bufref;

        set_bufref(&bufref, buf);
        if (buf_write_all(buf, eap->forceit) == FAIL)
          ++error;
        /* an autocommand may have deleted the buffer */
        if (!bufref_valid(&bufref))
          buf = firstbuf;
      }
      eap->forceit = save_forceit; /* check_overwrite() may set it */
    }
  }
  if (exiting)
  {
    if (quitCallback != NULL)
    {
      quitCallback(NULL, eap->forceit);
    }
    not_exiting();
  }
}

/*
 * Check the 'write' option.
 * Return TRUE and give a message when it's not st.
 */
int not_writing(void)
{
  if (p_write)
    return FALSE;
  emsg(_("E142: File not written: Writing is disabled by 'write' option"));
  return TRUE;
}

/*
 * Check if a buffer is read-only (either 'readonly' option is set or file is
 * read-only). Ask for overruling in a dialog. Return TRUE and give an error
 * message when the buffer is readonly.
 */
static int
check_readonly(int *forceit, buf_T *buf)
{
  stat_T st;

  /* Handle a file being readonly when the 'readonly' option is set or when
     * the file exists and permissions are read-only.
     * We will send 0777 to check_file_readonly(), as the "perm" variable is
     * important for device checks but not here. */
  if (!*forceit && (buf->b_p_ro || (mch_stat((char *)buf->b_ffname, &st) >= 0 && check_file_readonly(buf->b_ffname, 0777))))
  {
    if (buf->b_p_ro)
      emsg(_(e_readonly));
    else
      semsg(_("E505: \"%s\" is read-only (add ! to override)"),
            buf->b_fname);
    return TRUE;
  }

  return FALSE;
}

/*
 * Try to abandon the current file and edit a new or existing file.
 * "fnum" is the number of the file, if zero use "ffname_arg"/"sfname_arg".
 * "lnum" is the line number for the cursor in the new file (if non-zero).
 *
 * Return:
 * GETFILE_ERROR for "normal" error,
 * GETFILE_NOT_WRITTEN for "not written" error,
 * GETFILE_SAME_FILE for success
 * GETFILE_OPEN_OTHER for successfully opening another file.
 */
int getfile(
    int fnum,
    char_u *ffname_arg,
    char_u *sfname_arg,
    int setpm,
    linenr_T lnum,
    int forceit)
{
  char_u *ffname = ffname_arg;
  char_u *sfname = sfname_arg;
  int other;
  int retval;
  char_u *free_me = NULL;

  if (text_locked())
    return GETFILE_ERROR;
  if (curbuf_locked())
    return GETFILE_ERROR;

  if (fnum == 0)
  {
    /* make ffname full path, set sfname */
    fname_expand(curbuf, &ffname, &sfname);
    other = otherfile(ffname);
    free_me = ffname; /* has been allocated, free() later */
  }
  else
    other = (fnum != curbuf->b_fnum);

  if (other)
    ++no_wait_return; /* don't wait for autowrite message */
  if (other && !forceit && curbuf->b_nwindows == 1 && !buf_hide(curbuf) && curbufIsChanged() && autowrite(curbuf, forceit) == FAIL)
  {
    {
      if (other)
        --no_wait_return;
      no_write_message();
      retval = GETFILE_NOT_WRITTEN; /* file has been changed */
      goto theend;
    }
  }
  if (other)
    --no_wait_return;
  if (setpm)
    setpcmark();
  if (!other)
  {
    if (lnum != 0)
      curwin->w_cursor.lnum = lnum;
    check_cursor_lnum();
    beginline(BL_SOL | BL_FIX);
    retval = GETFILE_SAME_FILE; /* it's in the same file */
  }
  else if (do_ecmd(fnum, ffname, sfname, NULL, lnum,
                   (buf_hide(curbuf) ? ECMD_HIDE : 0) + (forceit ? ECMD_FORCEIT : 0),
                   curwin) == OK)
    retval = GETFILE_OPEN_OTHER; /* opened another file */
  else
    retval = GETFILE_ERROR; /* error encountered */

theend:
  vim_free(free_me);
  return retval;
}

/*
 * start editing a new file
 *
 *     fnum: file number; if zero use ffname/sfname
 *   ffname: the file name
 *		- full path if sfname used,
 *		- any file name if sfname is NULL
 *		- empty string to re-edit with the same file name (but may be
 *		    in a different directory)
 *		- NULL to start an empty buffer
 *   sfname: the short file name (or NULL)
 *	eap: contains the command to be executed after loading the file and
 *	     forced 'ff' and 'fenc'
 *  newlnum: if > 0: put cursor on this line number (if possible)
 *	     if ECMD_LASTL: use last position in loaded file
 *	     if ECMD_LAST: use last position in all files
 *	     if ECMD_ONE: use first line
 *    flags:
 *	   ECMD_HIDE: if TRUE don't free the current buffer
 *     ECMD_SET_HELP: set b_help flag of (new) buffer before opening file
 *	 ECMD_OLDBUF: use existing buffer if it exists
 *	ECMD_FORCEIT: ! used for Ex command
 *	 ECMD_ADDBUF: don't edit, just add to buffer list
 *   oldwin: Should be "curwin" when editing a new buffer in the current
 *	     window, NULL when splitting the window first.  When not NULL info
 *	     of the previous buffer for "oldwin" is stored.
 *
 * return FAIL for failure, OK otherwise
 */
int do_ecmd(
    int fnum,
    char_u *ffname,
    char_u *sfname,
    exarg_T *eap, /* can be NULL! */
    linenr_T newlnum,
    int flags,
    win_T *oldwin)
{
  int other_file;       /* TRUE if editing another file */
  int oldbuf;           /* TRUE if using existing buffer */
  int auto_buf = FALSE; /* TRUE if autocommands brought us
					   into the buffer unexpectedly */
  char_u *new_name = NULL;
#if defined(FEAT_EVAL)
  int did_set_swapcommand = FALSE;
#endif
  buf_T *buf;
  bufref_T bufref;
  bufref_T old_curbuf;
  char_u *free_fname = NULL;
#ifdef FEAT_BROWSE
  char_u *browse_file = NULL;
#endif
  int retval = FAIL;
  long n;
  pos_T orig_pos;
  linenr_T topline = 0;
  int newcol = -1;
  int solcol = -1;
  pos_T *pos;
  char_u *command = NULL;
  int readfile_flags = 0;
  int did_inc_redrawing_disabled = FALSE;
  long *so_ptr = curwin->w_p_so >= 0 ? &curwin->w_p_so : &p_so;

  if (eap != NULL)
    command = eap->do_ecmd_cmd;
  set_bufref(&old_curbuf, curbuf);

  if (fnum != 0)
  {
    if (fnum == curbuf->b_fnum) /* file is already being edited */
      return OK;                /* nothing to do */
    other_file = TRUE;
  }
  else
  {
#ifdef FEAT_BROWSE
    if (cmdmod.browse)
    {
      if (
          au_has_group((char_u *)"FileExplorer"))
      {
        /* No browsing supported but we do have the file explorer:
		 * Edit the directory. */
        if (ffname == NULL || !mch_isdir(ffname))
          ffname = (char_u *)".";
      }
      else
      {
        browse_file = do_browse(0, (char_u *)_("Edit File"), ffname,
                                NULL, NULL, NULL, curbuf);
        if (browse_file == NULL)
          goto theend;
        ffname = browse_file;
      }
    }
#endif
    /* if no short name given, use ffname for short name */
    if (sfname == NULL)
      sfname = ffname;
#ifdef USE_FNAME_CASE
    if (sfname != NULL)
      fname_case(sfname, 0); /* set correct case for sfname */
#endif

    if ((flags & ECMD_ADDBUF) && (ffname == NULL || *ffname == NUL))
      goto theend;

    if (ffname == NULL)
      other_file = TRUE;
    /* there is no file name */
    else if (*ffname == NUL && curbuf->b_ffname == NULL)
      other_file = FALSE;
    else
    {
      if (*ffname == NUL) /* re-edit with same file name */
      {
        ffname = curbuf->b_ffname;
        sfname = curbuf->b_fname;
      }
      free_fname = fix_fname(ffname); /* may expand to full path name */
      if (free_fname != NULL)
        ffname = free_fname;
      other_file = otherfile(ffname);
    }
  }

  /*
     * if the file was changed we may not be allowed to abandon it
     * - if we are going to re-edit the same file
     * - or if we are the only window on this file and if ECMD_HIDE is FALSE
     */
  if (((!other_file && !(flags & ECMD_OLDBUF)) || (curbuf->b_nwindows == 1 && !(flags & (ECMD_HIDE | ECMD_ADDBUF)))) && check_changed(curbuf, (p_awa ? CCGD_AW : 0) | (other_file ? 0 : CCGD_MULTWIN) | ((flags & ECMD_FORCEIT) ? CCGD_FORCEIT : 0) | (eap == NULL ? 0 : CCGD_EXCMD)))
  {
    if (fnum == 0 && other_file && ffname != NULL)
      (void)setaltfname(ffname, sfname, newlnum < 0 ? 0 : newlnum);
    goto theend;
  }

  /*
     * End Visual mode before switching to another buffer, so the text can be
     * copied into the GUI selection buffer.
     */
  reset_VIsual();

#if defined(FEAT_EVAL)
  if ((command != NULL || newlnum > (linenr_T)0) && *get_vim_var_str(VV_SWAPCOMMAND) == NUL)
  {
    int len;
    char_u *p;

    /* Set v:swapcommand for the SwapExists autocommands. */
    if (command != NULL)
      len = (int)STRLEN(command) + 3;
    else
      len = 30;
    p = alloc(len);
    if (p != NULL)
    {
      if (command != NULL)
        vim_snprintf((char *)p, len, ":%s\r", command);
      else
        vim_snprintf((char *)p, len, "%ldG", (long)newlnum);
      set_vim_var_string(VV_SWAPCOMMAND, p, -1);
      did_set_swapcommand = TRUE;
      vim_free(p);
    }
  }
#endif

  /*
     * If we are starting to edit another file, open a (new) buffer.
     * Otherwise we re-use the current buffer.
     */
  if (other_file)
  {
    if (!(flags & ECMD_ADDBUF))
    {
      if (!cmdmod.keepalt)
        curwin->w_alt_fnum = curbuf->b_fnum;
      if (oldwin != NULL)
        buflist_altfpos(oldwin);
    }

    if (fnum)
      buf = buflist_findnr(fnum);
    else
    {
      if (flags & ECMD_ADDBUF)
      {
        linenr_T tlnum = 1L;

        if (command != NULL)
        {
          tlnum = atol((char *)command);
          if (tlnum <= 0)
            tlnum = 1L;
        }
        (void)buflist_new(ffname, sfname, tlnum, BLN_LISTED);
        goto theend;
      }
      buf = buflist_new(ffname, sfname, 0L,
                        BLN_CURBUF | ((flags & ECMD_SET_HELP) ? 0 : BLN_LISTED));

      /* autocommands may change curwin and curbuf */
      if (oldwin != NULL)
        oldwin = curwin;
      set_bufref(&old_curbuf, curbuf);
    }
    if (buf == NULL)
      goto theend;
    if (buf->b_ml.ml_mfp == NULL) /* no memfile yet */
    {
      oldbuf = FALSE;
    }
    else /* existing memfile */
    {
      oldbuf = TRUE;
      set_bufref(&bufref, buf);
      (void)buf_check_timestamp(buf, FALSE);
      /* Check if autocommands made the buffer invalid or changed the
	     * current buffer. */
      if (!bufref_valid(&bufref) || curbuf != old_curbuf.br_buf)
        goto theend;
#ifdef FEAT_EVAL
      if (aborting()) /* autocmds may abort script processing */
        goto theend;
#endif
    }

    /* May jump to last used line number for a loaded buffer or when asked
	 * for explicitly */
    if ((oldbuf && newlnum == ECMD_LASTL) || newlnum == ECMD_LAST)
    {
      pos = buflist_findfpos(buf);
      newlnum = pos->lnum;
      solcol = pos->col;
    }

    /*
	 * Make the (new) buffer the one used by the current window.
	 * If the old buffer becomes unused, free it if ECMD_HIDE is FALSE.
	 * If the current buffer was empty and has no file name, curbuf
	 * is returned by buflist_new(), nothing to do here.
	 */
    if (buf != curbuf)
    {
      /*
	     * Be careful: The autocommands may delete any buffer and change
	     * the current buffer.
	     * - If the buffer we are going to edit is deleted, give up.
	     * - If the current buffer is deleted, prefer to load the new
	     *   buffer when loading a buffer is required.  This avoids
	     *   loading another buffer which then must be closed again.
	     * - If we ended up in the new buffer already, need to skip a few
	     *	 things, set auto_buf.
	     */
      if (buf->b_fname != NULL)
        new_name = vim_strsave(buf->b_fname);
      set_bufref(&au_new_curbuf, buf);
      apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
      if (!bufref_valid(&au_new_curbuf))
      {
        /* new buffer has been deleted */
        delbuf_msg(new_name); /* frees new_name */
        goto theend;
      }
#ifdef FEAT_EVAL
      if (aborting()) /* autocmds may abort script processing */
      {
        vim_free(new_name);
        goto theend;
      }
#endif
      if (buf == curbuf) /* already in new buffer */
        auto_buf = TRUE;
      else
      {
        win_T *the_curwin = curwin;

        /* Set the w_closing flag to avoid that autocommands close the
		 * window.  And set b_locked for the same reason. */
        the_curwin->w_closing = TRUE;
        ++buf->b_locked;

        if (curbuf == old_curbuf.br_buf)
          buf_copy_options(buf, BCO_ENTER);

        /* Close the link to the current buffer. This will set
		 * oldwin->w_buffer to NULL. */
        u_sync(FALSE);
        close_buffer(oldwin, curbuf,
                     (flags & ECMD_HIDE) ? 0 : DOBUF_UNLOAD, FALSE);

        the_curwin->w_closing = FALSE;
        --buf->b_locked;

#ifdef FEAT_EVAL
        /* autocmds may abort script processing */
        if (aborting() && curwin->w_buffer != NULL)
        {
          vim_free(new_name);
          goto theend;
        }
#endif
        /* Be careful again, like above. */
        if (!bufref_valid(&au_new_curbuf))
        {
          /* new buffer has been deleted */
          delbuf_msg(new_name); /* frees new_name */
          goto theend;
        }
        if (buf == curbuf) /* already in new buffer */
          auto_buf = TRUE;
        else
        {
          curwin->w_buffer = buf;
          curbuf = buf;
          ++curbuf->b_nwindows;

          /* Set 'fileformat', 'binary' and 'fenc' when forced. */
          if (!oldbuf && eap != NULL)
          {
            set_file_options(TRUE, eap);
            set_forced_fenc(eap);
          }
        }

        /* May get the window options from the last time this buffer
		 * was in this window (or another window).  If not used
		 * before, reset the local window options to the global
		 * values.  Also restores old folding stuff. */
        get_winopts(curbuf);
      }
      vim_free(new_name);
      au_new_curbuf.br_buf = NULL;
      au_new_curbuf.br_buf_free_count = 0;
    }

    curwin->w_pcmark.lnum = 1;
    curwin->w_pcmark.col = 0;
  }
  else /* !other_file */
  {
    if ((flags & ECMD_ADDBUF) || check_fname() == FAIL)
      goto theend;

    oldbuf = (flags & ECMD_OLDBUF);
  }

  /* Don't redraw until the cursor is in the right line, otherwise
     * autocommands may cause ml_get errors. */
  ++RedrawingDisabled;
  did_inc_redrawing_disabled = TRUE;

  buf = curbuf;
  if ((flags & ECMD_SET_HELP) || keep_help_flag)
  {
    prepare_help_buffer();
  }
  else
  {
    /* Don't make a buffer listed if it's a help buffer.  Useful when
	 * using CTRL-O to go back to a help file. */
    if (!curbuf->b_help)
      set_buflisted(TRUE);
  }

  /* If autocommands change buffers under our fingers, forget about
     * editing the file. */
  if (buf != curbuf)
    goto theend;
#ifdef FEAT_EVAL
  if (aborting()) /* autocmds may abort script processing */
    goto theend;
#endif

  /* Since we are starting to edit a file, consider the filetype to be
     * unset.  Helps for when an autocommand changes files and expects syntax
     * highlighting to work in the other file. */
  did_filetype = FALSE;

  /*
 * other_file	oldbuf
 *  FALSE	FALSE	    re-edit same file, buffer is re-used
 *  FALSE	TRUE	    re-edit same file, nothing changes
 *  TRUE	FALSE	    start editing new file, new buffer
 *  TRUE	TRUE	    start editing in existing buffer (nothing to do)
 */
  if (!other_file && !oldbuf) /* re-use the buffer */
  {
    set_last_cursor(curwin); /* may set b_last_cursor */
    if (newlnum == ECMD_LAST || newlnum == ECMD_LASTL)
    {
      newlnum = curwin->w_cursor.lnum;
      solcol = curwin->w_cursor.col;
    }
    buf = curbuf;
    if (buf->b_fname != NULL)
      new_name = vim_strsave(buf->b_fname);
    else
      new_name = NULL;
    set_bufref(&bufref, buf);

    if (p_ur < 0 || curbuf->b_ml.ml_line_count <= p_ur)
    {
      /* Save all the text, so that the reload can be undone.
	     * Sync first so that this is a separate undo-able action. */
      u_sync(FALSE);
      if (u_savecommon(0, curbuf->b_ml.ml_line_count + 1, 0, TRUE) == FAIL)
      {
        vim_free(new_name);
        goto theend;
      }
      u_unchanged(curbuf);
      buf_freeall(curbuf, BFA_KEEP_UNDO);

      /* tell readfile() not to clear or reload undo info */
      readfile_flags = READ_KEEP_UNDO;
    }
    else
      buf_freeall(curbuf, 0); /* free all things for buffer */

    /* If autocommands deleted the buffer we were going to re-edit, give
	 * up and jump to the end. */
    if (!bufref_valid(&bufref))
    {
      delbuf_msg(new_name); /* frees new_name */
      goto theend;
    }
    vim_free(new_name);

    /* If autocommands change buffers under our fingers, forget about
	 * re-editing the file.  Should do the buf_clear_file(), but perhaps
	 * the autocommands changed the buffer... */
    if (buf != curbuf)
      goto theend;
#ifdef FEAT_EVAL
    if (aborting()) /* autocmds may abort script processing */
      goto theend;
#endif
    buf_clear_file(curbuf);
    curbuf->b_op_start.lnum = 0; /* clear '[ and '] marks */
    curbuf->b_op_end.lnum = 0;
  }

  /*
 * If we get here we are sure to start editing
 */
  /* Assume success now */
  retval = OK;

  /*
     * Check if we are editing the w_arg_idx file in the argument list.
     */
  check_arg_idx(curwin);

  if (!auto_buf)
  {
    /*
	 * Set cursor and init window before reading the file and executing
	 * autocommands.  This allows for the autocommands to position the
	 * cursor.
	 */
    curwin_init();

#ifdef FEAT_FOLDING
    /* It's possible that all lines in the buffer changed.  Need to update
	 * automatic folding for all windows where it's used. */
    {
      win_T *win;
      tabpage_T *tp;

      FOR_ALL_TAB_WINDOWS(tp, win)
      if (win->w_buffer == curbuf)
        foldUpdateAll(win);
    }
#endif

    /* Change directories when the 'acd' option is set. */
    DO_AUTOCHDIR;

    /*
	 * Careful: open_buffer() and apply_autocmds() may change the current
	 * buffer and window.
	 */
    orig_pos = curwin->w_cursor;
    topline = curwin->w_topline;
    if (!oldbuf) /* need to read the file */
    {
      swap_exists_action = SEA_DIALOG;
      curbuf->b_flags |= BF_CHECK_RO; /* set/reset 'ro' flag */

      /*
	     * Open the buffer and read the file.
	     */
#if defined(FEAT_EVAL)
      if (should_abort(open_buffer(FALSE, eap, readfile_flags)))
        retval = FAIL;
#else
      (void)open_buffer(FALSE, eap, readfile_flags);
#endif

      if (swap_exists_action == SEA_QUIT)
        retval = FAIL;
      handle_swap_exists(&old_curbuf);
    }
    else
    {
      /* Read the modelines, but only to set window-local options.  Any
	     * buffer-local options have already been set and may have been
	     * changed by the user. */
      do_modelines(OPT_WINONLY);

      apply_autocmds_retval(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf,
                            &retval);
      apply_autocmds_retval(EVENT_BUFWINENTER, NULL, NULL, FALSE, curbuf,
                            &retval);
    }
    check_arg_idx(curwin);

    /* If autocommands change the cursor position or topline, we should
	 * keep it.  Also when it moves within a line. But not when it moves
	 * to the first non-blank. */
    if (!EQUAL_POS(curwin->w_cursor, orig_pos))
    {
      char_u *text = ml_get_curline();

      if (curwin->w_cursor.lnum != orig_pos.lnum || curwin->w_cursor.col != (int)(skipwhite(text) - text))
      {
        newlnum = curwin->w_cursor.lnum;
        newcol = curwin->w_cursor.col;
      }
    }
    if (curwin->w_topline == topline)
      topline = 0;

    /* Even when cursor didn't move we need to recompute topline. */
    changed_line_abv_curs();
  }

#ifdef FEAT_DIFF
  /* Tell the diff stuff that this buffer is new and/or needs updating.
     * Also needed when re-editing the same buffer, because unloading will
     * have removed it as a diff buffer. */
  if (curwin->w_p_diff)
  {
    diff_buf_add(curbuf);
    diff_invalidate(curbuf);
  }
#endif

  if (command == NULL)
  {
    if (newcol >= 0) /* position set by autocommands */
    {
      curwin->w_cursor.lnum = newlnum;
      curwin->w_cursor.col = newcol;
      check_cursor();
    }
    else if (newlnum > 0) /* line number from caller or old position */
    {
      curwin->w_cursor.lnum = newlnum;
      check_cursor_lnum();
      if (solcol >= 0 && !p_sol)
      {
        /* 'sol' is off: Use last known column. */
        curwin->w_cursor.col = solcol;
        check_cursor_col();
        curwin->w_cursor.coladd = 0;
        curwin->w_set_curswant = TRUE;
      }
      else
        beginline(BL_SOL | BL_FIX);
    }
    else /* no line number, go to last line in Ex mode */
    {
      if (exmode_active)
        curwin->w_cursor.lnum = curbuf->b_ml.ml_line_count;
      beginline(BL_WHITE | BL_FIX);
    }
  }

  /* Check if cursors in other windows on the same buffer are still valid */
  check_lnums(FALSE);

  /*
     * Did not read the file, need to show some info about the file.
     * Do this after setting the cursor.
     */
  if (oldbuf && !auto_buf)
  {
    int msg_scroll_save = msg_scroll;

    /* Obey the 'O' flag in 'cpoptions': overwrite any previous file
	 * message. */
    if (shortmess(SHM_OVERALL) && !exiting && p_verbose == 0)
      msg_scroll = FALSE;
    if (!msg_scroll) /* wait a bit when overwriting an error msg */
      check_for_delay(FALSE);
    msg_start();
    msg_scroll = msg_scroll_save;
    msg_scrolled_ign = TRUE;

    if (!shortmess(SHM_FILEINFO))
      fileinfo(FALSE, TRUE, FALSE);

    msg_scrolled_ign = FALSE;
  }

#ifdef FEAT_VIMINFO
  curbuf->b_last_used = vim_time();
#endif

  if (command != NULL)
    do_cmdline(command, NULL, NULL, DOCMD_VERBOSE);

#ifdef FEAT_KEYMAP
  if (curbuf->b_kmap_state & KEYMAP_INIT)
    (void)keymap_init();
#endif

  --RedrawingDisabled;
  did_inc_redrawing_disabled = FALSE;
  if (!skip_redraw)
  {
    n = *so_ptr;
    if (topline == 0 && command == NULL)
      *so_ptr = 9999; // force cursor halfway the window
    update_topline();
    curwin->w_scbind_pos = curwin->w_topline;
    *so_ptr = n;
    redraw_curbuf_later(NOT_VALID); /* redraw this buffer later */
  }

  if (p_im)
    need_start_insertmode = TRUE;

#ifdef FEAT_AUTOCHDIR
  /* Change directories when the 'acd' option is set and we aren't already in
     * that directory (should already be done above). Expect getcwd() to be
     * faster than calling shorten_fnames() unnecessarily. */
  if (p_acd && curbuf->b_ffname != NULL)
  {
    char_u curdir[MAXPATHL];
    char_u filedir[MAXPATHL];

    vim_strncpy(filedir, curbuf->b_ffname, MAXPATHL - 1);
    *gettail_sep(filedir) = NUL;
    if (mch_dirname(curdir, MAXPATHL) != FAIL && vim_fnamecmp(curdir, filedir) != 0)
      do_autochdir();
  }
#endif

theend:
  if (did_inc_redrawing_disabled)
    --RedrawingDisabled;
#if defined(FEAT_EVAL)
  if (did_set_swapcommand)
    set_vim_var_string(VV_SWAPCOMMAND, NULL, -1);
#endif
#ifdef FEAT_BROWSE
  vim_free(browse_file);
#endif
  vim_free(free_fname);
  return retval;
}

static void
delbuf_msg(char_u *name)
{
  semsg(_("E143: Autocommands unexpectedly deleted new buffer %s"),
        name == NULL ? (char_u *)"" : name);
  vim_free(name);
  au_new_curbuf.br_buf = NULL;
  au_new_curbuf.br_buf_free_count = 0;
}

static int append_indent = 0; /* autoindent for first line */

/*
 * ":insert" and ":append", also used by ":change"
 */
void ex_append(exarg_T *eap)
{
  char_u *theline;
  int did_undo = FALSE;
  linenr_T lnum = eap->line2;
  int indent = 0;
  char_u *p;
  int vcol;
  int empty = (curbuf->b_ml.ml_flags & ML_EMPTY);

  /* the ! flag toggles autoindent */
  if (eap->forceit)
    curbuf->b_p_ai = !curbuf->b_p_ai;

  /* First autoindent comes from the line we start on */
  if (eap->cmdidx != CMD_change && curbuf->b_p_ai && lnum > 0)
    append_indent = get_indent_lnum(lnum);

  if (eap->cmdidx != CMD_append)
    --lnum;

  /* when the buffer is empty need to delete the dummy line */
  if (empty && lnum == 1)
    lnum = 0;

  State = INSERT; /* behave like in Insert mode */
  if (curbuf->b_p_iminsert == B_IMODE_LMAP)
    State |= LANGMAP;

  for (;;)
  {
    msg_scroll = TRUE;
    need_wait_return = FALSE;
    if (curbuf->b_p_ai)
    {
      if (append_indent >= 0)
      {
        indent = append_indent;
        append_indent = -1;
      }
      else if (lnum > 0)
        indent = get_indent_lnum(lnum);
    }
    ex_keep_indent = FALSE;
    if (eap->getline == NULL)
    {
      /* No getline() function, use the lines that follow. This ends
	     * when there is no more. */
      if (eap->nextcmd == NULL || *eap->nextcmd == NUL)
        break;
      p = vim_strchr(eap->nextcmd, NL);
      if (p == NULL)
        p = eap->nextcmd + STRLEN(eap->nextcmd);
      theline = vim_strnsave(eap->nextcmd, (int)(p - eap->nextcmd));
      if (*p != NUL)
        ++p;
      eap->nextcmd = p;
    }
    else
    {
      int save_State = State;

      /* Set State to avoid the cursor shape to be set to INSERT mode
	     * when getline() returns. */
      State = CMDLINE;
      theline = eap->getline(
#ifdef FEAT_EVAL
          eap->cstack->cs_looplevel > 0 ? -1 :
#endif
                                        NUL,
          eap->cookie, indent);
      State = save_State;
    }
    lines_left = Rows - 1;
    if (theline == NULL)
      break;

    /* Using ^ CTRL-D in getexmodeline() makes us repeat the indent. */
    if (ex_keep_indent)
      append_indent = indent;

    /* Look for the "." after automatic indent. */
    vcol = 0;
    for (p = theline; indent > vcol; ++p)
    {
      if (*p == ' ')
        ++vcol;
      else if (*p == TAB)
        vcol += 8 - vcol % 8;
      else
        break;
    }
    if ((p[0] == '.' && p[1] == NUL) || (!did_undo && u_save(lnum, lnum + 1 + (empty ? 1 : 0)) == FAIL))
    {
      vim_free(theline);
      break;
    }

    /* don't use autoindent if nothing was typed. */
    if (p[0] == NUL)
      theline[0] = NUL;

    did_undo = TRUE;
    ml_append(lnum, theline, (colnr_T)0, FALSE);
    appended_lines_mark(lnum + (empty ? 1 : 0), 1L);

    vim_free(theline);
    ++lnum;

    if (empty)
    {
      ml_delete(2L, FALSE);
      empty = FALSE;
    }
  }
  State = NORMAL;

  if (eap->forceit)
    curbuf->b_p_ai = !curbuf->b_p_ai;

  /* "start" is set to eap->line2+1 unless that position is invalid (when
     * eap->line2 pointed to the end of the buffer and nothing was appended)
     * "end" is set to lnum when something has been appended, otherwise
     * it is the same than "start"  -- Acevedo */
  curbuf->b_op_start.lnum = (eap->line2 < curbuf->b_ml.ml_line_count) ? eap->line2 + 1 : curbuf->b_ml.ml_line_count;
  if (eap->cmdidx != CMD_append)
    --curbuf->b_op_start.lnum;
  curbuf->b_op_end.lnum = (eap->line2 < lnum)
                              ? lnum
                              : curbuf->b_op_start.lnum;
  curbuf->b_op_start.col = curbuf->b_op_end.col = 0;
  curwin->w_cursor.lnum = lnum;
  check_cursor_lnum();
  beginline(BL_SOL | BL_FIX);

  need_wait_return = FALSE; /* don't use wait_return() now */
  ex_no_reprint = TRUE;
}

/*
 * ":change"
 */
void ex_change(exarg_T *eap)
{
  linenr_T lnum;

  if (eap->line2 >= eap->line1 && u_save(eap->line1 - 1, eap->line2 + 1) == FAIL)
    return;

  /* the ! flag toggles autoindent */
  if (eap->forceit ? !curbuf->b_p_ai : curbuf->b_p_ai)
    append_indent = get_indent_lnum(eap->line1);

  for (lnum = eap->line2; lnum >= eap->line1; --lnum)
  {
    if (curbuf->b_ml.ml_flags & ML_EMPTY) /* nothing to delete */
      break;
    ml_delete(eap->line1, FALSE);
  }

  /* make sure the cursor is not beyond the end of the file now */
  check_cursor_lnum();
  deleted_lines_mark(eap->line1, (long)(eap->line2 - lnum));

  /* ":append" on the line above the deleted lines. */
  eap->line2 = eap->line1;
  ex_append(eap);
}

void ex_z(exarg_T *eap)
{
  char_u *x;
  long bigness;
  char_u *kind;
  int minus = 0;
  linenr_T start, end, curs, i;
  int j;
  linenr_T lnum = eap->line2;

  /* Vi compatible: ":z!" uses display height, without a count uses
     * 'scroll' */
  if (eap->forceit)
    bigness = curwin->w_height;
  else if (!ONE_WINDOW)
    bigness = curwin->w_height - 3;
  else
    bigness = curwin->w_p_scr * 2;
  if (bigness < 1)
    bigness = 1;

  x = eap->arg;
  kind = x;
  if (*kind == '-' || *kind == '+' || *kind == '=' || *kind == '^' || *kind == '.')
    ++x;
  while (*x == '-' || *x == '+')
    ++x;

  if (*x != 0)
  {
    if (!VIM_ISDIGIT(*x))
    {
      emsg(_("E144: non-numeric argument to :z"));
      return;
    }
    else
    {
      bigness = atol((char *)x);

      /* bigness could be < 0 if atol(x) overflows. */
      if (bigness > 2 * curbuf->b_ml.ml_line_count || bigness < 0)
        bigness = 2 * curbuf->b_ml.ml_line_count;

      p_window = bigness;
      if (*kind == '=')
        bigness += 2;
    }
  }

  /* the number of '-' and '+' multiplies the distance */
  if (*kind == '-' || *kind == '+')
    for (x = kind + 1; *x == *kind; ++x)
      ;

  switch (*kind)
  {
  case '-':
    start = lnum - bigness * (linenr_T)(x - kind) + 1;
    end = start + bigness - 1;
    curs = end;
    break;

  case '=':
    start = lnum - (bigness + 1) / 2 + 1;
    end = lnum + (bigness + 1) / 2 - 1;
    curs = lnum;
    minus = 1;
    break;

  case '^':
    start = lnum - bigness * 2;
    end = lnum - bigness;
    curs = lnum - bigness;
    break;

  case '.':
    start = lnum - (bigness + 1) / 2 + 1;
    end = lnum + (bigness + 1) / 2 - 1;
    curs = end;
    break;

  default: /* '+' */
    start = lnum;
    if (*kind == '+')
      start += bigness * (linenr_T)(x - kind - 1) + 1;
    else if (eap->addr_count == 0)
      ++start;
    end = start + bigness - 1;
    curs = end;
    break;
  }

  if (start < 1)
    start = 1;

  if (end > curbuf->b_ml.ml_line_count)
    end = curbuf->b_ml.ml_line_count;

  if (curs > curbuf->b_ml.ml_line_count)
    curs = curbuf->b_ml.ml_line_count;
  else if (curs < 1)
    curs = 1;

  for (i = start; i <= end; i++)
  {
    if (minus && i == lnum)
    {
      msg_putchar('\n');

      for (j = 1; j < Columns; j++)
        msg_putchar('-');
    }

    print_line(i, eap->flags & EXFLAG_NR, eap->flags & EXFLAG_LIST);

    if (minus && i == lnum)
    {
      msg_putchar('\n');

      for (j = 1; j < Columns; j++)
        msg_putchar('-');
    }
  }

  if (curwin->w_cursor.lnum != curs)
  {
    curwin->w_cursor.lnum = curs;
    curwin->w_cursor.col = 0;
  }
  ex_no_reprint = TRUE;
}

/*
 * Check if the restricted flag is set.
 * If so, give an error message and return TRUE.
 * Otherwise, return FALSE.
 */
int check_restricted(void)
{
  if (restricted)
  {
    emsg(_("E145: Shell commands and some functionality not allowed in rvim"));
    return TRUE;
  }
  return FALSE;
}

/*
 * Check if the secure flag is set (.exrc or .vimrc in current directory).
 * If so, give an error message and return TRUE.
 * Otherwise, return FALSE.
 */
int check_secure(void)
{
  if (secure)
  {
    secure = 2;
    emsg(_(e_curdir));
    return TRUE;
  }
#ifdef HAVE_SANDBOX
  /*
     * In the sandbox more things are not allowed, including the things
     * disallowed in secure mode.
     */
  if (sandbox != 0)
  {
    emsg(_(e_sandbox));
    return TRUE;
  }
#endif
  return FALSE;
}

static char_u *old_sub = NULL;    /* previous substitute pattern */
static int global_need_beginline; /* call beginline() after ":g" */

/*
 * Flags that are kept between calls to :substitute.
 */
typedef struct
{
  int do_all;    /* do multiple substitutions per line */
  int do_ask;    /* ask for confirmation */
  int do_count;  /* count only */
  int do_error;  /* if false, ignore errors */
  int do_print;  /* print last line with subs. */
  int do_list;   /* list last line with subs. */
  int do_number; /* list last line with line nr*/
  int do_ic;     /* ignore case flag */
} subflags_T;

/* do_sub()
 *
 * Perform a substitution from line eap->line1 to line eap->line2 using the
 * command pointed to by eap->arg which should be of the form:
 *
 * /pattern/substitution/{flags}
 *
 * The usual escapes are supported as described in the regexp docs.
 */
void do_sub(exarg_T *eap)
{
  linenr_T lnum;
  long i = 0;
  regmmatch_T regmatch;
  static subflags_T subflags = {FALSE, FALSE, FALSE, TRUE, FALSE,
                                FALSE, FALSE, 0};
#ifdef FEAT_EVAL
  subflags_T subflags_save;
#endif
  int save_do_all;                 /* remember user specified 'g' flag */
  int save_do_ask;                 /* remember user specified 'c' flag */
  char_u *pat = NULL, *sub = NULL; /* init for GCC */
  int delimiter;
  int sublen;
  int got_quit = FALSE;
  int got_match = FALSE;
  int temp;
  int which_pat;
  char_u *cmd;
  int save_State;
  linenr_T first_line = 0; /* first changed line */
  linenr_T last_line = 0;  /* below last changed line AFTER the
					 * change */
  linenr_T old_line_count = curbuf->b_ml.ml_line_count;
  linenr_T line2;
  long nmatch;           /* number of lines in match */
  char_u *sub_firstline; /* allocated copy of first sub line */
  int endcolumn = FALSE; /* cursor in last column when done */
  pos_T old_cursor = curwin->w_cursor;
  int start_nsubs;
#ifdef FEAT_EVAL
  int save_ma = 0;
#endif

  cmd = eap->arg;
  if (!global_busy)
  {
    sub_nsubs = 0;
    sub_nlines = 0;
  }
  start_nsubs = sub_nsubs;

  if (eap->cmdidx == CMD_tilde)
    which_pat = RE_LAST; /* use last used regexp */
  else
    which_pat = RE_SUBST; /* use last substitute regexp */

  /* new pattern and substitution */
  if (eap->cmd[0] == 's' && *cmd != NUL && !VIM_ISWHITE(*cmd) && vim_strchr((char_u *)"0123456789cegriIp|\"", *cmd) == NULL)
  {
    /* don't accept alphanumeric for separator */
    if (isalpha(*cmd))
    {
      emsg(_("E146: Regular expressions can't be delimited by letters"));
      return;
    }
    /*
	 * undocumented vi feature:
	 *  "\/sub/" and "\?sub?" use last used search pattern (almost like
	 *  //sub/r).  "\&sub&" use last substitute pattern (like //sub/).
	 */
    if (*cmd == '\\')
    {
      ++cmd;
      if (vim_strchr((char_u *)"/?&", *cmd) == NULL)
      {
        emsg(_(e_backslash));
        return;
      }
      if (*cmd != '&')
        which_pat = RE_SEARCH; /* use last '/' pattern */
      pat = (char_u *)"";      /* empty search pattern */
      delimiter = *cmd++;      /* remember delimiter character */
    }
    else /* find the end of the regexp */
    {
      which_pat = RE_LAST; /* use last used regexp */
      delimiter = *cmd++;  /* remember delimiter character */
      pat = cmd;           /* remember start of search pat */
      cmd = skip_regexp(cmd, delimiter, p_magic, &eap->arg);
      if (cmd[0] == delimiter) /* end delimiter found */
        *cmd++ = NUL;          /* replace it with a NUL */
    }

    /*
	 * Small incompatibility: vi sees '\n' as end of the command, but in
	 * Vim we want to use '\n' to find/substitute a NUL.
	 */
    sub = cmd; /* remember the start of the substitution */

    while (cmd[0])
    {
      if (cmd[0] == delimiter) /* end delimiter found */
      {
        *cmd++ = NUL; /* replace it with a NUL */
        break;
      }
      if (cmd[0] == '\\' && cmd[1] != 0) /* skip escaped characters */
        ++cmd;
      MB_PTR_ADV(cmd);
    }

    if (!eap->skip)
    {
      /* In POSIX vi ":s/pat/%/" uses the previous subst. string. */
      if (STRCMP(sub, "%") == 0 && vim_strchr(p_cpo, CPO_SUBPERCENT) != NULL)
      {
        if (old_sub == NULL) /* there is no previous command */
        {
          emsg(_(e_nopresub));
          return;
        }
        sub = old_sub;
      }
      else
      {
        vim_free(old_sub);
        old_sub = vim_strsave(sub);
      }
    }
  }
  else if (!eap->skip) /* use previous pattern and substitution */
  {
    if (old_sub == NULL) /* there is no previous command */
    {
      emsg(_(e_nopresub));
      return;
    }
    pat = NULL; /* search_regcomp() will use previous pattern */
    sub = old_sub;

    /* Vi compatibility quirk: repeating with ":s" keeps the cursor in the
	 * last column after using "$". */
    endcolumn = (curwin->w_curswant == MAXCOL);
  }

  /* Recognize ":%s/\n//" and turn it into a join command, which is much
     * more efficient.
     * TODO: find a generic solution to make line-joining operations more
     * efficient, avoid allocating a string that grows in size.
     */
  if (pat != NULL && STRCMP(pat, "\\n") == 0 && *sub == NUL && (*cmd == NUL || (cmd[1] == NUL && (*cmd == 'g' || *cmd == 'l' || *cmd == 'p' || *cmd == '#'))))
  {
    linenr_T joined_lines_count;

    curwin->w_cursor.lnum = eap->line1;
    if (*cmd == 'l')
      eap->flags = EXFLAG_LIST;
    else if (*cmd == '#')
      eap->flags = EXFLAG_NR;
    else if (*cmd == 'p')
      eap->flags = EXFLAG_PRINT;

    /* The number of lines joined is the number of lines in the range plus
	 * one.  One less when the last line is included. */
    joined_lines_count = eap->line2 - eap->line1 + 1;
    if (eap->line2 < curbuf->b_ml.ml_line_count)
      ++joined_lines_count;
    if (joined_lines_count > 1)
    {
      (void)do_join(joined_lines_count, FALSE, TRUE, FALSE, TRUE);
      sub_nsubs = joined_lines_count - 1;
      sub_nlines = 1;
      (void)do_sub_msg(FALSE);
      ex_may_print(eap);
    }

    if (!cmdmod.keeppatterns)
      save_re_pat(RE_SUBST, pat, p_magic);
#ifdef FEAT_CMDHIST
    /* put pattern in history */
    add_to_history(HIST_SEARCH, pat, TRUE, NUL);
#endif

    return;
  }

  /*
     * Find trailing options.  When '&' is used, keep old options.
     */
  if (*cmd == '&')
    ++cmd;
  else
  {
    if (!p_ed)
    {
      if (p_gd) /* default is global on */
        subflags.do_all = TRUE;
      else
        subflags.do_all = FALSE;
      subflags.do_ask = FALSE;
    }
    subflags.do_error = TRUE;
    subflags.do_print = FALSE;
    subflags.do_list = FALSE;
    subflags.do_count = FALSE;
    subflags.do_number = FALSE;
    subflags.do_ic = 0;
  }
  while (*cmd)
  {
    /*
	 * Note that 'g' and 'c' are always inverted, also when p_ed is off.
	 * 'r' is never inverted.
	 */
    if (*cmd == 'g')
      subflags.do_all = !subflags.do_all;
    else if (*cmd == 'c')
      subflags.do_ask = !subflags.do_ask;
    else if (*cmd == 'n')
      subflags.do_count = TRUE;
    else if (*cmd == 'e')
      subflags.do_error = !subflags.do_error;
    else if (*cmd == 'r') /* use last used regexp */
      which_pat = RE_LAST;
    else if (*cmd == 'p')
      subflags.do_print = TRUE;
    else if (*cmd == '#')
    {
      subflags.do_print = TRUE;
      subflags.do_number = TRUE;
    }
    else if (*cmd == 'l')
    {
      subflags.do_print = TRUE;
      subflags.do_list = TRUE;
    }
    else if (*cmd == 'i') /* ignore case */
      subflags.do_ic = 'i';
    else if (*cmd == 'I') /* don't ignore case */
      subflags.do_ic = 'I';
    else
      break;
    ++cmd;
  }
  if (subflags.do_count)
    subflags.do_ask = FALSE;

  // HACK: For now, instead of hanging / hitting a block input path... at least let the user know what went wrong.
  // Next step: Implement a state machine so we can handle confirm without blocking.
  if (subflags.do_ask)
  {
    emsg("libvim: Confirm flag (c) is not currently supported for substitution.");
    return;
  }

  save_do_all = subflags.do_all;
  save_do_ask = subflags.do_ask;

  /*
     * check for a trailing count
     */
  cmd = skipwhite(cmd);
  if (VIM_ISDIGIT(*cmd))
  {
    i = getdigits(&cmd);
    if (i <= 0 && !eap->skip && subflags.do_error)
    {
      emsg(_(e_zerocount));
      return;
    }
    eap->line1 = eap->line2;
    eap->line2 += i - 1;
    if (eap->line2 > curbuf->b_ml.ml_line_count)
      eap->line2 = curbuf->b_ml.ml_line_count;
  }

  /*
     * check for trailing command or garbage
     */
  cmd = skipwhite(cmd);
  if (*cmd && *cmd != '"') /* if not end-of-line or comment */
  {
    eap->nextcmd = check_nextcmd(cmd);
    if (eap->nextcmd == NULL)
    {
      emsg(_(e_trailing));
      return;
    }
  }

  if (eap->skip) /* not executing commands, only parsing */
    return;

  if (!subflags.do_count && !curbuf->b_p_ma)
  {
    /* Substitution is not allowed in non-'modifiable' buffer */
    emsg(_(e_modifiable));
    return;
  }

  if (search_regcomp(pat, RE_SUBST, which_pat, SEARCH_HIS, &regmatch) == FAIL)
  {
    if (subflags.do_error)
      emsg(_(e_invcmd));
    return;
  }

  /* the 'i' or 'I' flag overrules 'ignorecase' and 'smartcase' */
  if (subflags.do_ic == 'i')
    regmatch.rmm_ic = TRUE;
  else if (subflags.do_ic == 'I')
    regmatch.rmm_ic = FALSE;

  sub_firstline = NULL;

  /*
     * ~ in the substitute pattern is replaced with the old pattern.
     * We do it here once to avoid it to be replaced over and over again.
     * But don't do it when it starts with "\=", then it's an expression.
     */
  if (!(sub[0] == '\\' && sub[1] == '='))
    sub = regtilde(sub, p_magic);

  /*
     * Check for a match on each line.
     */
  line2 = eap->line2;
  for (lnum = eap->line1; lnum <= line2 && !(got_quit
#if defined(FEAT_EVAL)
                                             || aborting()
#endif
                                           );
       ++lnum)
  {
    nmatch = vim_regexec_multi(&regmatch, curwin, curbuf, lnum,
                               (colnr_T)0, NULL, NULL);
    if (nmatch)
    {
      colnr_T copycol;
      colnr_T matchcol;
      colnr_T prev_matchcol = MAXCOL;
      char_u *new_end, *new_start = NULL;
      unsigned new_start_len = 0;
      char_u *p1;
      int did_sub = FALSE;
      int lastone;
      int len, copy_len, needed_len;
      long nmatch_tl = 0; /* nr of lines matched below lnum */
      int do_again;       /* do it again after joining lines */
      int skip_match = FALSE;
      linenr_T sub_firstlnum; /* nr of first sub line */
      /*
	     * The new text is build up step by step, to avoid too much
	     * copying.  There are these pieces:
	     * sub_firstline	The old text, unmodified.
	     * copycol		Column in the old text where we started
	     *			looking for a match; from here old text still
	     *			needs to be copied to the new text.
	     * matchcol		Column number of the old text where to look
	     *			for the next match.  It's just after the
	     *			previous match or one further.
	     * prev_matchcol	Column just after the previous match (if any).
	     *			Mostly equal to matchcol, except for the first
	     *			match and after skipping an empty match.
	     * regmatch.*pos	Where the pattern matched in the old text.
	     * new_start	The new text, all that has been produced so
	     *			far.
	     * new_end		The new text, where to append new text.
	     *
	     * lnum		The line number where we found the start of
	     *			the match.  Can be below the line we searched
	     *			when there is a \n before a \zs in the
	     *			pattern.
	     * sub_firstlnum	The line number in the buffer where to look
	     *			for a match.  Can be different from "lnum"
	     *			when the pattern or substitute string contains
	     *			line breaks.
	     *
	     * Special situations:
	     * - When the substitute string contains a line break, the part up
	     *   to the line break is inserted in the text, but the copy of
	     *   the original line is kept.  "sub_firstlnum" is adjusted for
	     *   the inserted lines.
	     * - When the matched pattern contains a line break, the old line
	     *   is taken from the line at the end of the pattern.  The lines
	     *   in the match are deleted later, "sub_firstlnum" is adjusted
	     *   accordingly.
	     *
	     * The new text is built up in new_start[].  It has some extra
	     * room to avoid using alloc()/free() too often.  new_start_len is
	     * the length of the allocated memory at new_start.
	     *
	     * Make a copy of the old line, so it won't be taken away when
	     * updating the screen or handling a multi-line match.  The "old_"
	     * pointers point into this copy.
	     */
      sub_firstlnum = lnum;
      copycol = 0;
      matchcol = 0;

      /* At first match, remember current cursor position. */
      if (!got_match)
      {
        setpcmark();
        got_match = TRUE;
      }

      /*
	     * Loop until nothing more to replace in this line.
	     * 1. Handle match with empty string.
	     * 2. If do_ask is set, ask for confirmation.
	     * 3. substitute the string.
	     * 4. if do_all is set, find next match
	     * 5. break if there isn't another match in this line
	     */
      for (;;)
      {
        /* Advance "lnum" to the line where the match starts.  The
		 * match does not start in the first line when there is a line
		 * break before \zs. */
        if (regmatch.startpos[0].lnum > 0)
        {
          lnum += regmatch.startpos[0].lnum;
          sub_firstlnum += regmatch.startpos[0].lnum;
          nmatch -= regmatch.startpos[0].lnum;
          VIM_CLEAR(sub_firstline);
        }

        if (sub_firstline == NULL)
        {
          sub_firstline = vim_strsave(ml_get(sub_firstlnum));
          if (sub_firstline == NULL)
          {
            vim_free(new_start);
            goto outofmem;
          }
        }

        /* Save the line number of the last change for the final
		 * cursor position (just like Vi). */
        curwin->w_cursor.lnum = lnum;
        do_again = FALSE;

        /*
		 * 1. Match empty string does not count, except for first
		 * match.  This reproduces the strange vi behaviour.
		 * This also catches endless loops.
		 */
        if (matchcol == prev_matchcol && regmatch.endpos[0].lnum == 0 && matchcol == regmatch.endpos[0].col)
        {
          if (sub_firstline[matchcol] == NUL)
            /* We already were at the end of the line.  Don't look
			 * for a match in this line again. */
            skip_match = TRUE;
          else
          {
            /* search for a match at next column */
            if (has_mbyte)
              matchcol += mb_ptr2len(sub_firstline + matchcol);
            else
              ++matchcol;
          }
          goto skip;
        }

        /* Normally we continue searching for a match just after the
		 * previous match. */
        matchcol = regmatch.endpos[0].col;
        prev_matchcol = matchcol;

        /*
		 * 2. If do_count is set only increase the counter.
		 *    If do_ask is set, ask for confirmation.
		 */
        if (subflags.do_count)
        {
          /* For a multi-line match, put matchcol at the NUL at
		     * the end of the line and set nmatch to one, so that
		     * we continue looking for a match on the next line.
		     * Avoids that ":s/\nB\@=//gc" get stuck. */
          if (nmatch > 1)
          {
            matchcol = (colnr_T)STRLEN(sub_firstline);
            nmatch = 1;
            skip_match = TRUE;
          }
          sub_nsubs++;
          did_sub = TRUE;
#ifdef FEAT_EVAL
          /* Skip the substitution, unless an expression is used,
		     * then it is evaluated in the sandbox. */
          if (!(sub[0] == '\\' && sub[1] == '='))
#endif
            goto skip;
        }

        if (subflags.do_ask)
        {
          int typed = 0;

          /* change State to CONFIRM, so that the mouse works
		     * properly */
          save_State = State;
          State = CONFIRM;
          curwin->w_cursor.col = regmatch.startpos[0].col;
          if (curwin->w_p_crb)
            do_check_cursorbind();

          /* When 'cpoptions' contains "u" don't sync undo when
		     * asking for confirmation. */
          if (vim_strchr(p_cpo, CPO_UNDO) != NULL)
            ++no_u_sync;

          /*
		     * Loop until 'y', 'n', 'q', CTRL-E or CTRL-Y typed.
		     */
          while (subflags.do_ask)
          {
            if (exmode_active)
            {
              char_u *resp;
              colnr_T sc, ec;

              print_line_no_prefix(lnum,
                                   subflags.do_number, subflags.do_list);

              getvcol(curwin, &curwin->w_cursor, &sc, NULL, NULL);
              curwin->w_cursor.col = regmatch.endpos[0].col - 1;
              if (curwin->w_cursor.col < 0)
                curwin->w_cursor.col = 0;
              getvcol(curwin, &curwin->w_cursor, NULL, NULL, &ec);
              if (subflags.do_number || curwin->w_p_nu)
              {
                int numw = number_width(curwin) + 1;
                sc += numw;
                ec += numw;
              }
              msg_start();
              for (i = 0; i < (long)sc; ++i)
                msg_putchar(' ');
              for (; i <= (long)ec; ++i)
                msg_putchar('^');

              resp = getexmodeline('?', NULL, 0);
              if (resp != NULL)
              {
                typed = *resp;
                vim_free(resp);
              }
            }
            else
            {
              char_u *orig_line = NULL;
              int len_change = 0;
#ifdef FEAT_FOLDING
              int save_p_fen = curwin->w_p_fen;

              curwin->w_p_fen = FALSE;
#endif
              /* Invert the matched string.
			     * Remove the inversion afterwards. */
              temp = RedrawingDisabled;
              RedrawingDisabled = 0;

              if (new_start != NULL)
              {
                /* There already was a substitution, we would
				 * like to show this to the user.  We cannot
				 * really update the line, it would change
				 * what matches.  Temporarily replace the line
				 * and change it back afterwards. */
                orig_line = vim_strsave(ml_get(lnum));
                if (orig_line != NULL)
                {
                  char_u *new_line = concat_str(new_start,
                                                sub_firstline + copycol);

                  if (new_line == NULL)
                    VIM_CLEAR(orig_line);
                  else
                  {
                    /* Position the cursor relative to the
					 * end of the line, the previous
					 * substitute may have inserted or
					 * deleted characters before the
					 * cursor. */
                    len_change = (int)STRLEN(new_line) - (int)STRLEN(orig_line);
                    curwin->w_cursor.col += len_change;
                    ml_replace(lnum, new_line, FALSE);
                  }
                }
              }

              search_match_lines = regmatch.endpos[0].lnum - regmatch.startpos[0].lnum;
              search_match_endcol = regmatch.endpos[0].col + len_change;
              highlight_match = TRUE;

              update_topline();
              validate_cursor();
              update_screen(SOME_VALID);
              highlight_match = FALSE;
              redraw_later(SOME_VALID);

#ifdef FEAT_FOLDING
              curwin->w_p_fen = save_p_fen;
#endif
              if (msg_row == Rows - 1)
                msg_didout = FALSE; /* avoid a scroll-up */
              msg_starthere();
              i = msg_scroll;
              msg_scroll = 0; /* truncate msg when
							   needed */
              msg_no_more = TRUE;
              /* write message same highlighting as for
			     * wait_return */
              smsg_attr(HL_ATTR(HLF_R),
                        _("replace with %s (y/n/a/q/l/^E/^Y)?"), sub);
              msg_no_more = FALSE;
              msg_scroll = i;
              showruler(TRUE);
              windgoto(msg_row, msg_col);
              RedrawingDisabled = temp;

              ++no_mapping; /* don't map this key */
              ++allow_keys; /* allow special keys */
              typed = plain_vgetc();
              --allow_keys;
              --no_mapping;

              /* clear the question */
              msg_didout = FALSE; /* don't scroll up */
              msg_col = 0;
              gotocmdline(TRUE);

              /* restore the line */
              if (orig_line != NULL)
                ml_replace(lnum, orig_line, FALSE);
            }

            need_wait_return = FALSE; /* no hit-return prompt */
            if (typed == 'q' || typed == ESC || typed == Ctrl_C
#ifdef UNIX
                || typed == intr_char
#endif
            )
            {
              got_quit = TRUE;
              break;
            }
            if (typed == 'n')
              break;
            if (typed == 'y')
              break;
            if (typed == 'l')
            {
              /* last: replace and then stop */
              subflags.do_all = FALSE;
              line2 = lnum;
              break;
            }
            if (typed == 'a')
            {
              subflags.do_ask = FALSE;
              break;
            }
          }
          State = save_State;
          if (vim_strchr(p_cpo, CPO_UNDO) != NULL)
            --no_u_sync;

          if (typed == 'n')
          {
            /* For a multi-line match, put matchcol at the NUL at
			 * the end of the line and set nmatch to one, so that
			 * we continue looking for a match on the next line.
			 * Avoids that ":%s/\nB\@=//gc" and ":%s/\n/,\r/gc"
			 * get stuck when pressing 'n'. */
            if (nmatch > 1)
            {
              matchcol = (colnr_T)STRLEN(sub_firstline);
              skip_match = TRUE;
            }
            goto skip;
          }
          if (got_quit)
            goto skip;
        }

        /* Move the cursor to the start of the match, so that we can
		 * use "\=col("."). */
        curwin->w_cursor.col = regmatch.startpos[0].col;

        /*
		 * 3. substitute the string.
		 */
#ifdef FEAT_EVAL
        save_ma = curbuf->b_p_ma;
        if (subflags.do_count)
        {
          // prevent accidentally changing the buffer by a function
          curbuf->b_p_ma = FALSE;
          sandbox++;
        }
        // Save flags for recursion.  They can change for e.g.
        // :s/^/\=execute("s#^##gn")
        subflags_save = subflags;
#endif
        // get length of substitution part
        sublen = vim_regsub_multi(&regmatch,
                                  sub_firstlnum - regmatch.startpos[0].lnum,
                                  sub, sub_firstline, FALSE, p_magic, TRUE);
#ifdef FEAT_EVAL
        // If getting the substitute string caused an error, don't do
        // the replacement.
        // Don't keep flags set by a recursive call.
        subflags = subflags_save;
        if (aborting() || subflags.do_count)
        {
          curbuf->b_p_ma = save_ma;
          if (sandbox > 0)
            sandbox--;
          goto skip;
        }
#endif

        /* When the match included the "$" of the last line it may
		 * go beyond the last line of the buffer. */
        if (nmatch > curbuf->b_ml.ml_line_count - sub_firstlnum + 1)
        {
          nmatch = curbuf->b_ml.ml_line_count - sub_firstlnum + 1;
          skip_match = TRUE;
        }

        /* Need room for:
		 * - result so far in new_start (not for first sub in line)
		 * - original text up to match
		 * - length of substituted part
		 * - original text after match
		 * Adjust text properties here, since we have all information
		 * needed.
		 */
        if (nmatch == 1)
        {
          p1 = sub_firstline;
        }
        else
        {
          p1 = ml_get(sub_firstlnum + nmatch - 1);
          nmatch_tl += nmatch - 1;
        }
        copy_len = regmatch.startpos[0].col - copycol;
        needed_len = copy_len + ((unsigned)STRLEN(p1) - regmatch.endpos[0].col) + sublen + 1;
        if (new_start == NULL)
        {
          /*
		     * Get some space for a temporary buffer to do the
		     * substitution into (and some extra space to avoid
		     * too many calls to alloc()/free()).
		     */
          new_start_len = needed_len + 50;
          if ((new_start = alloc(new_start_len)) == NULL)
            goto outofmem;
          *new_start = NUL;
          new_end = new_start;
        }
        else
        {
          /*
		     * Check if the temporary buffer is long enough to do the
		     * substitution into.  If not, make it larger (with a bit
		     * extra to avoid too many calls to alloc()/free()).
		     */
          len = (unsigned)STRLEN(new_start);
          needed_len += len;
          if (needed_len > (int)new_start_len)
          {
            new_start_len = needed_len + 50;
            if ((p1 = alloc(new_start_len)) == NULL)
            {
              vim_free(new_start);
              goto outofmem;
            }
            mch_memmove(p1, new_start, (size_t)(len + 1));
            vim_free(new_start);
            new_start = p1;
          }
          new_end = new_start + len;
        }

        /*
		 * copy the text up to the part that matched
		 */
        mch_memmove(new_end, sub_firstline + copycol, (size_t)copy_len);
        new_end += copy_len;

        (void)vim_regsub_multi(&regmatch,
                               sub_firstlnum - regmatch.startpos[0].lnum,
                               sub, new_end, TRUE, p_magic, TRUE);
        sub_nsubs++;
        did_sub = TRUE;

        /* Move the cursor to the start of the line, to avoid that it
		 * is beyond the end of the line after the substitution. */
        curwin->w_cursor.col = 0;

        /* For a multi-line match, make a copy of the last matched
		 * line and continue in that one. */
        if (nmatch > 1)
        {
          sub_firstlnum += nmatch - 1;
          vim_free(sub_firstline);
          sub_firstline = vim_strsave(ml_get(sub_firstlnum));
          /* When going beyond the last line, stop substituting. */
          if (sub_firstlnum <= line2)
            do_again = TRUE;
          else
            subflags.do_all = FALSE;
        }

        /* Remember next character to be copied. */
        copycol = regmatch.endpos[0].col;

        if (skip_match)
        {
          /* Already hit end of the buffer, sub_firstlnum is one
		     * less than what it ought to be. */
          vim_free(sub_firstline);
          sub_firstline = vim_strsave((char_u *)"");
          copycol = 0;
        }

        /*
		 * Now the trick is to replace CTRL-M chars with a real line
		 * break.  This would make it impossible to insert a CTRL-M in
		 * the text.  The line break can be avoided by preceding the
		 * CTRL-M with a backslash.  To be able to insert a backslash,
		 * they must be doubled in the string and are halved here.
		 * That is Vi compatible.
		 */
        for (p1 = new_end; *p1; ++p1)
        {
          if (p1[0] == '\\' && p1[1] != NUL) /* remove backslash */
          {
            STRMOVE(p1, p1 + 1);
          }
          else if (*p1 == CAR)
          {
            if (u_inssub(lnum) == OK) // prepare for undo
            {
              colnr_T plen = (colnr_T)(p1 - new_start + 1);

              *p1 = NUL; // truncate up to the CR
              ml_append(lnum - 1, new_start, plen, FALSE);
              mark_adjust(lnum + 1, (linenr_T)MAXLNUM, 1L, 0L);
              if (subflags.do_ask)
                appended_lines(lnum - 1, 1L);
              else
              {
                if (first_line == 0)
                  first_line = lnum;
                last_line = lnum + 1;
              }
              // all line numbers increase
              ++sub_firstlnum;
              ++lnum;
              ++line2;
              // move the cursor to the new line, like Vi
              ++curwin->w_cursor.lnum;
              // copy the rest
              STRMOVE(new_start, p1 + 1);
              p1 = new_start - 1;
            }
          }
          else if (has_mbyte)
            p1 += (*mb_ptr2len)(p1)-1;
        }

        /*
		 * 4. If do_all is set, find next match.
		 * Prevent endless loop with patterns that match empty
		 * strings, e.g. :s/$/pat/g or :s/[a-z]* /(&)/g.
		 * But ":s/\n/#/" is OK.
		 */
      skip:
        /* We already know that we did the last subst when we are at
		 * the end of the line, except that a pattern like
		 * "bar\|\nfoo" may match at the NUL.  "lnum" can be below
		 * "line2" when there is a \zs in the pattern after a line
		 * break. */
        lastone = (skip_match || got_int || got_quit || lnum > line2 || !(subflags.do_all || do_again) || (sub_firstline[matchcol] == NUL && nmatch <= 1 && !re_multiline(regmatch.regprog)));
        nmatch = -1;

        /*
		 * Replace the line in the buffer when needed.  This is
		 * skipped when there are more matches.
		 * The check for nmatch_tl is needed for when multi-line
		 * matching must replace the lines before trying to do another
		 * match, otherwise "\@<=" won't work.
		 * When the match starts below where we start searching also
		 * need to replace the line first (using \zs after \n).
		 */
        if (lastone || nmatch_tl > 0 || (nmatch = vim_regexec_multi(&regmatch, curwin, curbuf, sub_firstlnum, matchcol, NULL, NULL)) == 0 || regmatch.startpos[0].lnum > 0)
        {
          if (new_start != NULL)
          {
            /*
			 * Copy the rest of the line, that didn't match.
			 * "matchcol" has to be adjusted, we use the end of
			 * the line as reference, because the substitute may
			 * have changed the number of characters.  Same for
			 * "prev_matchcol".
			 */
            STRCAT(new_start, sub_firstline + copycol);
            matchcol = (colnr_T)STRLEN(sub_firstline) - matchcol;
            prev_matchcol = (colnr_T)STRLEN(sub_firstline) - prev_matchcol;

            if (u_savesub(lnum) != OK)
              break;
            ml_replace(lnum, new_start, TRUE);

            if (nmatch_tl > 0)
            {
              /*
			     * Matched lines have now been substituted and are
			     * useless, delete them.  The part after the match
			     * has been appended to new_start, we don't need
			     * it in the buffer.
			     */
              ++lnum;
              if (u_savedel(lnum, nmatch_tl) != OK)
                break;
              for (i = 0; i < nmatch_tl; ++i)
                ml_delete(lnum, (int)FALSE);
              mark_adjust(lnum, lnum + nmatch_tl - 1,
                          (long)MAXLNUM, -nmatch_tl);
              if (subflags.do_ask)
                deleted_lines(lnum, nmatch_tl);
              --lnum;
              line2 -= nmatch_tl; /* nr of lines decreases */
              nmatch_tl = 0;
            }

            /* When asking, undo is saved each time, must also set
			 * changed flag each time. */
            if (subflags.do_ask)
              changed_bytes(lnum, 0);
            else
            {
              if (first_line == 0)
                first_line = lnum;
              last_line = lnum + 1;
            }

            sub_firstlnum = lnum;
            vim_free(sub_firstline); /* free the temp buffer */
            sub_firstline = new_start;
            new_start = NULL;
            matchcol = (colnr_T)STRLEN(sub_firstline) - matchcol;
            prev_matchcol = (colnr_T)STRLEN(sub_firstline) - prev_matchcol;
            copycol = 0;
          }
          if (nmatch == -1 && !lastone)
            nmatch = vim_regexec_multi(&regmatch, curwin, curbuf,
                                       sub_firstlnum, matchcol, NULL, NULL);

          /*
		     * 5. break if there isn't another match in this line
		     */
          if (nmatch <= 0)
          {
            /* If the match found didn't start where we were
			 * searching, do the next search in the line where we
			 * found the match. */
            if (nmatch == -1)
              lnum -= regmatch.startpos[0].lnum;
            break;
          }
        }

        line_breakcheck();
      }

      if (did_sub)
        ++sub_nlines;
      vim_free(new_start);      /* for when substitute was cancelled */
      VIM_CLEAR(sub_firstline); /* free the copy of the original line */
    }

    line_breakcheck();
  }

  if (first_line != 0)
  {
    /* Need to subtract the number of added lines from "last_line" to get
	 * the line number before the change (same as adding the number of
	 * deleted lines). */
    i = curbuf->b_ml.ml_line_count - old_line_count;
    changed_lines(first_line, 0, last_line - i, i);
  }

outofmem:
  vim_free(sub_firstline); /* may have to free allocated copy of the line */

  /* ":s/pat//n" doesn't move the cursor */
  if (subflags.do_count)
    curwin->w_cursor = old_cursor;

  if (sub_nsubs > start_nsubs)
  {
    /* Set the '[ and '] marks. */
    curbuf->b_op_start.lnum = eap->line1;
    curbuf->b_op_end.lnum = line2;
    curbuf->b_op_start.col = curbuf->b_op_end.col = 0;

    if (!global_busy)
    {
      /* when interactive leave cursor on the match */
      if (!subflags.do_ask)
      {
        if (endcolumn)
          coladvance((colnr_T)MAXCOL);
        else
          beginline(BL_WHITE | BL_FIX);
      }
      if (!do_sub_msg(subflags.do_count) && subflags.do_ask)
        msg("");
    }
    else
      global_need_beginline = TRUE;
    if (subflags.do_print)
      print_line(curwin->w_cursor.lnum,
                 subflags.do_number, subflags.do_list);
  }
  else if (!global_busy)
  {
    if (got_int) /* interrupted */
      emsg(_(e_interr));
    else if (got_match) /* did find something but nothing substituted */
      msg("");
    else if (subflags.do_error) /* nothing found */
      semsg(_(e_patnotf2), get_search_pat());
  }

#ifdef FEAT_FOLDING
  if (subflags.do_ask && hasAnyFolding(curwin))
    /* Cursor position may require updating */
    changed_window_setting();
#endif

  vim_regfree(regmatch.regprog);

  /* Restore the flag values, they can be used for ":&&". */
  subflags.do_all = save_do_all;
  subflags.do_ask = save_do_ask;
}

/*
 * Give message for number of substitutions.
 * Can also be used after a ":global" command.
 * Return TRUE if a message was given.
 */
int do_sub_msg(
    int count_only) /* used 'n' flag for ":s" */
{
  /*
     * Only report substitutions when:
     * - more than 'report' substitutions
     * - command was typed by user, or number of changed lines > 'report'
     * - giving messages is not disabled by 'lazyredraw'
     */
  if (((sub_nsubs > p_report && (KeyTyped || sub_nlines > 1 || p_report < 1)) || count_only) && messaging())
  {
    char *msg_single;
    char *msg_plural;

    if (got_int)
      STRCPY(msg_buf, _("(Interrupted) "));
    else
      *msg_buf = NUL;

    msg_single = count_only
                     ? NGETTEXT("%ld match on %ld line",
                                "%ld matches on %ld line", sub_nsubs)
                     : NGETTEXT("%ld substitution on %ld line",
                                "%ld substitutions on %ld line", sub_nsubs);
    msg_plural = count_only
                     ? NGETTEXT("%ld match on %ld lines",
                                "%ld matches on %ld lines", sub_nsubs)
                     : NGETTEXT("%ld substitution on %ld lines",
                                "%ld substitutions on %ld lines", sub_nsubs);

    vim_snprintf_add(msg_buf, sizeof(msg_buf),
                     NGETTEXT(msg_single, msg_plural, sub_nlines),
                     sub_nsubs, (long)sub_nlines);

    if (msg(msg_buf))
      /* save message to display it after redraw */
      set_keep_msg((char_u *)msg_buf, 0);
    return TRUE;
  }
  if (got_int)
  {
    emsg(_(e_interr));
    return TRUE;
  }
  return FALSE;
}

static void
global_exe_one(char_u *cmd, linenr_T lnum)
{
  curwin->w_cursor.lnum = lnum;
  curwin->w_cursor.col = 0;
  if (*cmd == NUL || *cmd == '\n')
    do_cmdline((char_u *)"p", NULL, NULL, DOCMD_NOWAIT);
  else
    do_cmdline(cmd, NULL, NULL, DOCMD_NOWAIT);
}

/*
 * Execute a global command of the form:
 *
 * g/pattern/X : execute X on all lines where pattern matches
 * v/pattern/X : execute X on all lines where pattern does not match
 *
 * where 'X' is an EX command
 *
 * The command character (as well as the trailing slash) is optional, and
 * is assumed to be 'p' if missing.
 *
 * This is implemented in two passes: first we scan the file for the pattern and
 * set a mark for each line that (not) matches. Secondly we execute the command
 * for each line that has a mark. This is required because after deleting
 * lines we do not know where to search for the next match.
 */
void ex_global(exarg_T *eap)
{
  linenr_T lnum; /* line number according to old situation */
  int ndone = 0;
  int type;    /* first char of cmd: 'v' or 'g' */
  char_u *cmd; /* command argument */

  char_u delim; /* delimiter, normally '/' */
  char_u *pat;
  regmmatch_T regmatch;
  int match;
  int which_pat;

  /* When nesting the command works on one line.  This allows for
     * ":g/found/v/notfound/command". */
  if (global_busy && (eap->line1 != 1 || eap->line2 != curbuf->b_ml.ml_line_count))
  {
    /* will increment global_busy to break out of the loop */
    emsg(_("E147: Cannot do :global recursive with a range"));
    return;
  }

  if (eap->forceit) /* ":global!" is like ":vglobal" */
    type = 'v';
  else
    type = *eap->cmd;
  cmd = eap->arg;
  which_pat = RE_LAST; /* default: use last used regexp */

  /*
     * undocumented vi feature:
     *	"\/" and "\?": use previous search pattern.
     *		 "\&": use previous substitute pattern.
     */
  if (*cmd == '\\')
  {
    ++cmd;
    if (vim_strchr((char_u *)"/?&", *cmd) == NULL)
    {
      emsg(_(e_backslash));
      return;
    }
    if (*cmd == '&')
      which_pat = RE_SUBST; /* use previous substitute pattern */
    else
      which_pat = RE_SEARCH; /* use previous search pattern */
    ++cmd;
    pat = (char_u *)"";
  }
  else if (*cmd == NUL)
  {
    emsg(_("E148: Regular expression missing from global"));
    return;
  }
  else
  {
    delim = *cmd; /* get the delimiter */
    if (delim)
      ++cmd;   /* skip delimiter if there is one */
    pat = cmd; /* remember start of pattern */
    cmd = skip_regexp(cmd, delim, p_magic, &eap->arg);
    if (cmd[0] == delim) /* end delimiter found */
      *cmd++ = NUL;      /* replace it with a NUL */
  }

  if (search_regcomp(pat, RE_BOTH, which_pat, SEARCH_HIS, &regmatch) == FAIL)
  {
    emsg(_(e_invcmd));
    return;
  }

  if (global_busy)
  {
    lnum = curwin->w_cursor.lnum;
    match = vim_regexec_multi(&regmatch, curwin, curbuf, lnum,
                              (colnr_T)0, NULL, NULL);
    if ((type == 'g' && match) || (type == 'v' && !match))
      global_exe_one(cmd, lnum);
  }
  else
  {
    /*
	 * pass 1: set marks for each (not) matching line
	 */
    for (lnum = eap->line1; lnum <= eap->line2 && !got_int; ++lnum)
    {
      /* a match on this line? */
      match = vim_regexec_multi(&regmatch, curwin, curbuf, lnum,
                                (colnr_T)0, NULL, NULL);
      if ((type == 'g' && match) || (type == 'v' && !match))
      {
        ml_setmarked(lnum);
        ndone++;
      }
      line_breakcheck();
    }

    /*
	 * pass 2: execute the command for each line that has been marked
	 */
    if (got_int)
      msg(_(e_interr));
    else if (ndone == 0)
    {
      if (type == 'v')
        smsg(_("Pattern found in every line: %s"), pat);
      else
        smsg(_("Pattern not found: %s"), pat);
    }
    else
    {
      global_exe(cmd);
    }

    ml_clearmarked(); /* clear rest of the marks */
  }

  vim_regfree(regmatch.regprog);
}

/*
 * Execute "cmd" on lines marked with ml_setmarked().
 */
void global_exe(char_u *cmd)
{
  linenr_T old_lcount;     /* b_ml.ml_line_count before the command */
  buf_T *old_buf = curbuf; /* remember what buffer we started in */
  linenr_T lnum;           /* line number according to old situation */

  /*
     * Set current position only once for a global command.
     * If global_busy is set, setpcmark() will not do anything.
     * If there is an error, global_busy will be incremented.
     */
  setpcmark();

  /* When the command writes a message, don't overwrite the command. */
  msg_didout = TRUE;

  sub_nsubs = 0;
  sub_nlines = 0;
  global_need_beginline = FALSE;
  global_busy = 1;
  old_lcount = curbuf->b_ml.ml_line_count;
  while (!got_int && (lnum = ml_firstmarked()) != 0 && global_busy == 1)
  {
    global_exe_one(cmd, lnum);
    ui_breakcheck();
  }

  global_busy = 0;
  if (global_need_beginline)
    beginline(BL_WHITE | BL_FIX);
  else
    check_cursor(); /* cursor may be beyond the end of the line */

  /* the cursor may not have moved in the text but a change in a previous
     * line may move it on the screen */
  changed_line_abv_curs();

  /* If it looks like no message was written, allow overwriting the
     * command with the report for number of changes. */
  if (msg_col == 0 && msg_scrolled == 0)
    msg_didout = FALSE;

  /* If substitutes done, report number of substitutes, otherwise report
     * number of extra or deleted lines.
     * Don't report extra or deleted lines in the edge case where the buffer
     * we are in after execution is different from the buffer we started in. */
  if (!do_sub_msg(FALSE) && curbuf == old_buf)
    msgmore(curbuf->b_ml.ml_line_count - old_lcount);
}

#ifdef FEAT_VIMINFO
int read_viminfo_sub_string(vir_T *virp, int force)
{
  if (force)
    vim_free(old_sub);
  if (force || old_sub == NULL)
    old_sub = viminfo_readstring(virp, 1, TRUE);
  return viminfo_readline(virp);
}

void write_viminfo_sub_string(FILE *fp)
{
  if (get_viminfo_parameter('/') != 0 && old_sub != NULL)
  {
    fputs(_("\n# Last Substitute String:\n$"), fp);
    viminfo_writestring(fp, old_sub);
  }
}
#endif /* FEAT_VIMINFO */

#if defined(EXITFREE) || defined(PROTO)
void free_old_sub(void)
{
  vim_free(old_sub);
}
#endif

#if defined(FEAT_QUICKFIX) || defined(PROTO)
/*
 * Set up for a tagpreview.
 * Return TRUE when it was created.
 */
int prepare_tagpreview(
    int undo_sync) /* sync undo when leaving the window */
{
  win_T *wp;

  /*
     * If there is already a preview window open, use that one.
     */
  if (!curwin->w_p_pvw)
  {
    FOR_ALL_WINDOWS(wp)
    if (wp->w_p_pvw)
      break;
    if (wp != NULL)
      win_enter(wp, undo_sync);
    else
    {
      /*
	     * There is no preview window open yet.  Create one.
	     */
      if (win_split(g_do_tagpreview > 0 ? g_do_tagpreview : 0, 0) == FAIL)
        return FALSE;
      curwin->w_p_pvw = TRUE;
      curwin->w_p_wfh = TRUE;
      RESET_BINDING(curwin); /* don't take over 'scrollbind'
					       and 'cursorbind' */
#ifdef FEAT_DIFF
      curwin->w_p_diff = FALSE; /* no 'diff' */
#endif
#ifdef FEAT_FOLDING
      curwin->w_p_fdc = 0; /* no 'foldcolumn' */
#endif
      return TRUE;
    }
  }
  return FALSE;
}

#endif

/*
 * ":help": open a read-only window on a help file
 */
void ex_help(exarg_T *eap)
{
  char_u *arg;
  char_u *tag;
  FILE *helpfd; /* file descriptor of help file */
  int n;
  int i;
  win_T *wp;
  int num_matches;
  char_u **matches;
  char_u *p;
  int empty_fnum = 0;
  int alt_fnum = 0;
  buf_T *buf;
#ifdef FEAT_MULTI_LANG
  int len;
  char_u *lang;
#endif
#ifdef FEAT_FOLDING
  int old_KeyTyped = KeyTyped;
#endif

  if (eap != NULL)
  {
    /*
	 * A ":help" command ends at the first LF, or at a '|' that is
	 * followed by some text.  Set nextcmd to the following command.
	 */
    for (arg = eap->arg; *arg; ++arg)
    {
      if (*arg == '\n' || *arg == '\r' || (*arg == '|' && arg[1] != NUL && arg[1] != '|'))
      {
        *arg++ = NUL;
        eap->nextcmd = arg;
        break;
      }
    }
    arg = eap->arg;

    if (eap->forceit && *arg == NUL && !curbuf->b_help)
    {
      emsg(_("E478: Don't panic!"));
      return;
    }

    if (eap->skip) /* not executing commands */
      return;
  }
  else
    arg = (char_u *)"";

  /* remove trailing blanks */
  p = arg + STRLEN(arg) - 1;
  while (p > arg && VIM_ISWHITE(*p) && p[-1] != '\\')
    *p-- = NUL;

#ifdef FEAT_MULTI_LANG
  /* Check for a specified language */
  lang = check_help_lang(arg);
#endif

  /* When no argument given go to the index. */
  if (*arg == NUL)
    arg = (char_u *)"help.txt";

  /*
     * Check if there is a match for the argument.
     */
  n = find_help_tags(arg, &num_matches, &matches,
                     eap != NULL && eap->forceit);

  i = 0;
#ifdef FEAT_MULTI_LANG
  if (n != FAIL && lang != NULL)
    /* Find first item with the requested language. */
    for (i = 0; i < num_matches; ++i)
    {
      len = (int)STRLEN(matches[i]);
      if (len > 3 && matches[i][len - 3] == '@' && STRICMP(matches[i] + len - 2, lang) == 0)
        break;
    }
#endif
  if (i >= num_matches || n == FAIL)
  {
#ifdef FEAT_MULTI_LANG
    if (lang != NULL)
      semsg(_("E661: Sorry, no '%s' help for %s"), lang, arg);
    else
#endif
      semsg(_("E149: Sorry, no help for %s"), arg);
    if (n != FAIL)
      FreeWild(num_matches, matches);
    return;
  }

  /* The first match (in the requested language) is the best match. */
  tag = vim_strsave(matches[i]);
  FreeWild(num_matches, matches);

  /*
     * Re-use an existing help window or open a new one.
     * Always open a new one for ":tab help".
     */
  if (!bt_help(curwin->w_buffer) || cmdmod.tab != 0)
  {
    if (cmdmod.tab != 0)
      wp = NULL;
    else
      FOR_ALL_WINDOWS(wp)
    if (bt_help(wp->w_buffer))
      break;
    if (wp != NULL && wp->w_buffer->b_nwindows > 0)
      win_enter(wp, TRUE);
    else
    {
      /*
	     * There is no help window yet.
	     * Try to open the file specified by the "helpfile" option.
	     */
      if ((helpfd = mch_fopen((char *)p_hf, READBIN)) == NULL)
      {
        smsg(_("Sorry, help file \"%s\" not found"), p_hf);
        goto erret;
      }
      fclose(helpfd);

      /* Split off help window; put it at far top if no position
	     * specified, the current window is vertically split and
	     * narrow. */
      n = WSP_HELP;
      if (cmdmod.split == 0 && curwin->w_width != Columns && curwin->w_width < 80)
        n |= WSP_TOP;
      if (win_split(0, n) == FAIL)
        goto erret;

      if (curwin->w_height < p_hh)
        win_setheight((int)p_hh);

      /*
	     * Open help file (do_ecmd() will set b_help flag, readfile() will
	     * set b_p_ro flag).
	     * Set the alternate file to the previously edited file.
	     */
      alt_fnum = curbuf->b_fnum;
      (void)do_ecmd(0, NULL, NULL, NULL, ECMD_LASTL,
                    ECMD_HIDE + ECMD_SET_HELP,
                    NULL); /* buffer is still open, don't store info */
      if (!cmdmod.keepalt)
        curwin->w_alt_fnum = alt_fnum;
      empty_fnum = curbuf->b_fnum;
    }
  }

  if (!p_im)
    restart_edit = 0; /* don't want insert mode in help file */

#ifdef FEAT_FOLDING
  /* Restore KeyTyped, setting 'filetype=help' may reset it.
     * It is needed for do_tag top open folds under the cursor. */
  KeyTyped = old_KeyTyped;
#endif

  if (tag != NULL)
    do_tag(tag, DT_HELP, 1, FALSE, TRUE);

  /* Delete the empty buffer if we're not using it.  Careful: autocommands
     * may have jumped to another window, check that the buffer is not in a
     * window. */
  if (empty_fnum != 0 && curbuf->b_fnum != empty_fnum)
  {
    buf = buflist_findnr(empty_fnum);
    if (buf != NULL && buf->b_nwindows == 0)
      wipe_buffer(buf, TRUE);
  }

  /* keep the previous alternate file */
  if (alt_fnum != 0 && curwin->w_alt_fnum == empty_fnum && !cmdmod.keepalt)
    curwin->w_alt_fnum = alt_fnum;

erret:
  vim_free(tag);
}

/*
 * ":helpclose": Close one help window
 */
void ex_helpclose(exarg_T *eap UNUSED)
{
  win_T *win;

  FOR_ALL_WINDOWS(win)
  {
    if (bt_help(win->w_buffer))
    {
      win_close(win, FALSE);
      return;
    }
  }
}

#if defined(FEAT_MULTI_LANG) || defined(PROTO)
/*
 * In an argument search for a language specifiers in the form "@xx".
 * Changes the "@" to NUL if found, and returns a pointer to "xx".
 * Returns NULL if not found.
 */
char_u *
check_help_lang(char_u *arg)
{
  int len = (int)STRLEN(arg);

  if (len >= 3 && arg[len - 3] == '@' && ASCII_ISALPHA(arg[len - 2]) && ASCII_ISALPHA(arg[len - 1]))
  {
    arg[len - 3] = NUL; /* remove the '@' */
    return arg + len - 2;
  }
  return NULL;
}
#endif

/*
 * Return a heuristic indicating how well the given string matches.  The
 * smaller the number, the better the match.  This is the order of priorities,
 * from best match to worst match:
 *	- Match with least alpha-numeric characters is better.
 *	- Match with least total characters is better.
 *	- Match towards the start is better.
 *	- Match starting with "+" is worse (feature instead of command)
 * Assumption is made that the matched_string passed has already been found to
 * match some string for which help is requested.  webb.
 */
int help_heuristic(
    char_u *matched_string,
    int offset,     /* offset for match */
    int wrong_case) /* no matching case */
{
  int num_letters;
  char_u *p;

  num_letters = 0;
  for (p = matched_string; *p; p++)
    if (ASCII_ISALNUM(*p))
      num_letters++;

  /*
     * Multiply the number of letters by 100 to give it a much bigger
     * weighting than the number of characters.
     * If there only is a match while ignoring case, add 5000.
     * If the match starts in the middle of a word, add 10000 to put it
     * somewhere in the last half.
     * If the match is more than 2 chars from the start, multiply by 200 to
     * put it after matches at the start.
     */
  if (ASCII_ISALNUM(matched_string[offset]) && offset > 0 && ASCII_ISALNUM(matched_string[offset - 1]))
    offset += 10000;
  else if (offset > 2)
    offset *= 200;
  if (wrong_case)
    offset += 5000;
  /* Features are less interesting than the subjects themselves, but "+"
     * alone is not a feature. */
  if (matched_string[0] == '+' && matched_string[1] != NUL)
    offset += 100;
  return (int)(100 * num_letters + STRLEN(matched_string) + offset);
}

/*
 * Compare functions for qsort() below, that checks the help heuristics number
 * that has been put after the tagname by find_tags().
 */
static int
help_compare(const void *s1, const void *s2)
{
  char *p1;
  char *p2;

  p1 = *(char **)s1 + strlen(*(char **)s1) + 1;
  p2 = *(char **)s2 + strlen(*(char **)s2) + 1;
  return strcmp(p1, p2);
}

/*
 * Find all help tags matching "arg", sort them and return in matches[], with
 * the number of matches in num_matches.
 * The matches will be sorted with a "best" match algorithm.
 * When "keep_lang" is TRUE try keeping the language of the current buffer.
 */
int find_help_tags(
    char_u *arg,
    int *num_matches,
    char_u ***matches,
    int keep_lang)
{
  char_u *s, *d;
  int i;
  static char *(mtable[]) = {"*", "g*", "[*", "]*", ":*",
                             "/*", "/\\*", "\"*", "**",
                             "cpo-*", "/\\(\\)", "/\\%(\\)",
                             "?", ":?", "?<CR>", "g?", "g?g?", "g??",
                             "-?", "q?", "v_g?",
                             "/\\?", "/\\z(\\)", "\\=", ":s\\=",
                             "[count]", "[quotex]",
                             "[range]", ":[range]",
                             "[pattern]", "\\|", "\\%$",
                             "s/\\~", "s/\\U", "s/\\L",
                             "s/\\1", "s/\\2", "s/\\3", "s/\\9"};
  static char *(rtable[]) = {"star", "gstar", "[star", "]star", ":star",
                             "/star", "/\\\\star", "quotestar", "starstar",
                             "cpo-star", "/\\\\(\\\\)", "/\\\\%(\\\\)",
                             "?", ":?", "?<CR>", "g?", "g?g?", "g??",
                             "-?", "q?", "v_g?",
                             "/\\\\?", "/\\\\z(\\\\)", "\\\\=", ":s\\\\=",
                             "\\[count]", "\\[quotex]",
                             "\\[range]", ":\\[range]",
                             "\\[pattern]", "\\\\bar", "/\\\\%\\$",
                             "s/\\\\\\~", "s/\\\\U", "s/\\\\L",
                             "s/\\\\1", "s/\\\\2", "s/\\\\3", "s/\\\\9"};
  static char *(expr_table[]) = {"!=?", "!~?", "<=?", "<?", "==?", "=~?",
                                 ">=?", ">?", "is?", "isnot?"};
  int flags;

  d = IObuff; /* assume IObuff is long enough! */

  if (STRNICMP(arg, "expr-", 5) == 0)
  {
    // When the string starting with "expr-" and containing '?' and matches
    // the table, it is taken literally.  Otherwise '?' is recognized as a
    // wildcard.
    for (i = (int)(sizeof(expr_table) / sizeof(char *)); --i >= 0;)
      if (STRCMP(arg + 5, expr_table[i]) == 0)
      {
        STRCPY(d, arg);
        break;
      }
  }
  else
  {
    // Recognize a few exceptions to the rule.  Some strings that contain
    // '*' with "star".  Otherwise '*' is recognized as a wildcard.
    for (i = (int)(sizeof(mtable) / sizeof(char *)); --i >= 0;)
      if (STRCMP(arg, mtable[i]) == 0)
      {
        STRCPY(d, rtable[i]);
        break;
      }
  }

  if (i < 0) /* no match in table */
  {
    /* Replace "\S" with "/\\S", etc.  Otherwise every tag is matched.
	 * Also replace "\%^" and "\%(", they match every tag too.
	 * Also "\zs", "\z1", etc.
	 * Also "\@<", "\@=", "\@<=", etc.
	 * And also "\_$" and "\_^". */
    if (arg[0] == '\\' && ((arg[1] != NUL && arg[2] == NUL) || (vim_strchr((char_u *)"%_z@", arg[1]) != NULL && arg[2] != NUL)))
    {
      STRCPY(d, "/\\\\");
      STRCPY(d + 3, arg + 1);
      /* Check for "/\\_$", should be "/\\_\$" */
      if (d[3] == '_' && d[4] == '$')
        STRCPY(d + 4, "\\$");
    }
    else
    {
      /* Replace:
	   * "[:...:]" with "\[:...:]"
	   * "[++...]" with "\[++...]"
	   * "\{" with "\\{"		   -- matching "} \}"
	   */
      if ((arg[0] == '[' && (arg[1] == ':' || (arg[1] == '+' && arg[2] == '+'))) || (arg[0] == '\\' && arg[1] == '{'))
        *d++ = '\\';

      /*
	   * If tag starts with "('", skip the "(". Fixes CTRL-] on ('option'.
	   */
      if (*arg == '(' && arg[1] == '\'')
        arg++;
      for (s = arg; *s; ++s)
      {
        /*
	     * Replace "|" with "bar" and '"' with "quote" to match the name of
	     * the tags for these commands.
	     * Replace "*" with ".*" and "?" with "." to match command line
	     * completion.
	     * Insert a backslash before '~', '$' and '.' to avoid their
	     * special meaning.
	     */
        if (d - IObuff > IOSIZE - 10) /* getting too long!? */
          break;
        switch (*s)
        {
        case '|':
          STRCPY(d, "bar");
          d += 3;
          continue;
        case '"':
          STRCPY(d, "quote");
          d += 5;
          continue;
        case '*':
          *d++ = '.';
          break;
        case '?':
          *d++ = '.';
          continue;
        case '$':
        case '.':
        case '~':
          *d++ = '\\';
          break;
        }

        /*
	     * Replace "^x" by "CTRL-X". Don't do this for "^_" to make
	     * ":help i_^_CTRL-D" work.
	     * Insert '-' before and after "CTRL-X" when applicable.
	     */
        if (*s < ' ' || (*s == '^' && s[1] && (ASCII_ISALPHA(s[1]) || vim_strchr((char_u *)"?@[\\]^", s[1]) != NULL)))
        {
          if (d > IObuff && d[-1] != '_' && d[-1] != '\\')
            *d++ = '_'; /* prepend a '_' to make x_CTRL-x */
          STRCPY(d, "CTRL-");
          d += 5;
          if (*s < ' ')
          {
#ifdef EBCDIC
            *d++ = CtrlChar(*s);
#else
            *d++ = *s + '@';
#endif
            if (d[-1] == '\\')
              *d++ = '\\'; /* double a backslash */
          }
          else
            *d++ = *++s;
          if (s[1] != NUL && s[1] != '_')
            *d++ = '_'; /* append a '_' */
          continue;
        }
        else if (*s == '^') /* "^" or "CTRL-^" or "^_" */
          *d++ = '\\';

        /*
	     * Insert a backslash before a backslash after a slash, for search
	     * pattern tags: "/\|" --> "/\\|".
	     */
        else if (s[0] == '\\' && s[1] != '\\' && *arg == '/' && s == arg + 1)
          *d++ = '\\';

        /* "CTRL-\_" -> "CTRL-\\_" to avoid the special meaning of "\_" in
	     * "CTRL-\_CTRL-N" */
        if (STRNICMP(s, "CTRL-\\_", 7) == 0)
        {
          STRCPY(d, "CTRL-\\\\");
          d += 7;
          s += 6;
        }

        *d++ = *s;

        /*
	     * If tag contains "({" or "([", tag terminates at the "(".
	     * This is for help on functions, e.g.: abs({expr}).
	     */
        if (*s == '(' && (s[1] == '{' || s[1] == '['))
          break;

        /*
	     * If tag starts with ', toss everything after a second '. Fixes
	     * CTRL-] on 'option'. (would include the trailing '.').
	     */
        if (*s == '\'' && s > arg && *arg == '\'')
          break;
        /* Also '{' and '}'. */
        if (*s == '}' && s > arg && *arg == '{')
          break;
      }
      *d = NUL;

      if (*IObuff == '`')
      {
        if (d > IObuff + 2 && d[-1] == '`')
        {
          /* remove the backticks from `command` */
          mch_memmove(IObuff, IObuff + 1, STRLEN(IObuff));
          d[-2] = NUL;
        }
        else if (d > IObuff + 3 && d[-2] == '`' && d[-1] == ',')
        {
          /* remove the backticks and comma from `command`, */
          mch_memmove(IObuff, IObuff + 1, STRLEN(IObuff));
          d[-3] = NUL;
        }
        else if (d > IObuff + 4 && d[-3] == '`' && d[-2] == '\\' && d[-1] == '.')
        {
          /* remove the backticks and dot from `command`\. */
          mch_memmove(IObuff, IObuff + 1, STRLEN(IObuff));
          d[-4] = NUL;
        }
      }
    }
  }

  *matches = (char_u **)"";
  *num_matches = 0;
  flags = TAG_HELP | TAG_REGEXP | TAG_NAMES | TAG_VERBOSE | TAG_NO_TAGFUNC;
  if (keep_lang)
    flags |= TAG_KEEP_LANG;
  if (find_tags(IObuff, num_matches, matches, flags, (int)MAXCOL, NULL) == OK && *num_matches > 0)
  {
    /* Sort the matches found on the heuristic number that is after the
	 * tag name. */
    qsort((void *)*matches, (size_t)*num_matches,
          sizeof(char_u *), help_compare);
    /* Delete more than TAG_MANY to reduce the size of the listing. */
    while (*num_matches > TAG_MANY)
      vim_free((*matches)[--*num_matches]);
  }
  return OK;
}

/*
 * Called when starting to edit a buffer for a help file.
 */
static void
prepare_help_buffer(void)
{
  char_u *p;

  curbuf->b_help = TRUE;
#ifdef FEAT_QUICKFIX
  set_string_option_direct((char_u *)"buftype", -1,
                           (char_u *)"help", OPT_FREE | OPT_LOCAL, 0);
#endif

  /*
     * Always set these options after jumping to a help tag, because the
     * user may have an autocommand that gets in the way.
     * Accept all ASCII chars for keywords, except ' ', '*', '"', '|', and
     * latin1 word characters (for translated help files).
     * Only set it when needed, buf_init_chartab() is some work.
     */
  p =
#ifdef EBCDIC
      (char_u *)"65-255,^*,^|,^\"";
#else
      (char_u *)"!-~,^*,^|,^\",192-255";
#endif
  if (STRCMP(curbuf->b_p_isk, p) != 0)
  {
    set_string_option_direct((char_u *)"isk", -1, p, OPT_FREE | OPT_LOCAL, 0);
    check_buf_options(curbuf);
    (void)buf_init_chartab(curbuf, FALSE);
  }

#ifdef FEAT_FOLDING
  /* Don't use the global foldmethod.*/
  set_string_option_direct((char_u *)"fdm", -1, (char_u *)"manual",
                           OPT_FREE | OPT_LOCAL, 0);
#endif

  curbuf->b_p_ts = 8;       /* 'tabstop' is 8 */
  curwin->w_p_list = FALSE; /* no list mode */

  curbuf->b_p_ma = FALSE;  /* not modifiable */
  curbuf->b_p_bin = FALSE; /* reset 'bin' before reading file */
  curwin->w_p_nu = 0;      /* no line numbers */
  curwin->w_p_rnu = 0;     /* no relative line numbers */
  RESET_BINDING(curwin);   /* no scroll or cursor binding */
#ifdef FEAT_ARABIC
  curwin->w_p_arab = FALSE; /* no arabic mode */
#endif
#ifdef FEAT_RIGHTLEFT
  curwin->w_p_rl = FALSE; /* help window is left-to-right */
#endif
#ifdef FEAT_FOLDING
  curwin->w_p_fen = FALSE; /* No folding in the help window */
#endif
#ifdef FEAT_DIFF
  curwin->w_p_diff = FALSE; /* No 'diff' */
#endif

  set_buflisted(FALSE);
}

/*
 * After reading a help file: May cleanup a help buffer when syntax
 * highlighting is not used.
 */
void fix_help_buffer(void)
{
  linenr_T lnum;
  char_u *line;
  int in_example = FALSE;
  int len;
  char_u *fname;
  char_u *p;
  char_u *rt;
  int mustfree;

  /* Set filetype to "help" if still needed. */
  if (STRCMP(curbuf->b_p_ft, "help") != 0)
  {
    ++curbuf_lock;
    set_option_value((char_u *)"ft", 0L, (char_u *)"help", OPT_LOCAL);
    --curbuf_lock;
  }

  {
    for (lnum = 1; lnum <= curbuf->b_ml.ml_line_count; ++lnum)
    {
      line = ml_get_buf(curbuf, lnum, FALSE);
      len = (int)STRLEN(line);
      if (in_example && len > 0 && !VIM_ISWHITE(line[0]))
      {
        /* End of example: non-white or '<' in first column. */
        if (line[0] == '<')
        {
          /* blank-out a '<' in the first column */
          line = ml_get_buf(curbuf, lnum, TRUE);
          line[0] = ' ';
        }
        in_example = FALSE;
      }
      if (!in_example && len > 0)
      {
        if (line[len - 1] == '>' && (len == 1 || line[len - 2] == ' '))
        {
          /* blank-out a '>' in the last column (start of example) */
          line = ml_get_buf(curbuf, lnum, TRUE);
          line[len - 1] = ' ';
          in_example = TRUE;
        }
        else if (line[len - 1] == '~')
        {
          /* blank-out a '~' at the end of line (header marker) */
          line = ml_get_buf(curbuf, lnum, TRUE);
          line[len - 1] = ' ';
        }
      }
    }
  }

  /*
     * In the "help.txt" and "help.abx" file, add the locally added help
     * files.  This uses the very first line in the help file.
     */
  fname = gettail(curbuf->b_fname);
  if (fnamecmp(fname, "help.txt") == 0
#ifdef FEAT_MULTI_LANG
      || (fnamencmp(fname, "help.", 5) == 0 && ASCII_ISALPHA(fname[5]) && ASCII_ISALPHA(fname[6]) && TOLOWER_ASC(fname[7]) == 'x' && fname[8] == NUL)
#endif
  )
  {
    for (lnum = 1; lnum < curbuf->b_ml.ml_line_count; ++lnum)
    {
      line = ml_get_buf(curbuf, lnum, FALSE);
      if (strstr((char *)line, "*local-additions*") == NULL)
        continue;

      /* Go through all directories in 'runtimepath', skipping
	     * $VIMRUNTIME. */
      p = p_rtp;
      while (*p != NUL)
      {
        copy_option_part(&p, NameBuff, MAXPATHL, ",");
        mustfree = FALSE;
        rt = vim_getenv((char_u *)"VIMRUNTIME", &mustfree);
        if (rt != NULL &&
            fullpathcmp(rt, NameBuff, FALSE, TRUE) != FPC_SAME)
        {
          int fcount;
          char_u **fnames;
          FILE *fd;
          char_u *s;
          int fi;
          vimconv_T vc;
          char_u *cp;

          /* Find all "doc/ *.txt" files in this directory. */
          add_pathsep(NameBuff);
#ifdef FEAT_MULTI_LANG
          STRCAT(NameBuff, "doc/*.??[tx]");
#else
          STRCAT(NameBuff, "doc/*.txt");
#endif
          if (gen_expand_wildcards(1, &NameBuff, &fcount,
                                   &fnames, EW_FILE | EW_SILENT) == OK &&
              fcount > 0)
          {
#ifdef FEAT_MULTI_LANG
            int i1, i2;
            char_u *f1, *f2;
            char_u *t1, *t2;
            char_u *e1, *e2;

            /* If foo.abx is found use it instead of foo.txt in
			 * the same directory. */
            for (i1 = 0; i1 < fcount; ++i1)
            {
              for (i2 = 0; i2 < fcount; ++i2)
              {
                if (i1 == i2)
                  continue;
                if (fnames[i1] == NULL || fnames[i2] == NULL)
                  continue;
                f1 = fnames[i1];
                f2 = fnames[i2];
                t1 = gettail(f1);
                t2 = gettail(f2);
                e1 = vim_strrchr(t1, '.');
                e2 = vim_strrchr(t2, '.');
                if (e1 == NULL || e2 == NULL)
                  continue;
                if (fnamecmp(e1, ".txt") != 0 && fnamecmp(e1, fname + 4) != 0)
                {
                  /* Not .txt and not .abx, remove it. */
                  VIM_CLEAR(fnames[i1]);
                  continue;
                }
                if (e1 - f1 != e2 - f2 || fnamencmp(f1, f2, e1 - f1) != 0)
                  continue;
                if (fnamecmp(e1, ".txt") == 0 && fnamecmp(e2, fname + 4) == 0)
                  /* use .abx instead of .txt */
                  VIM_CLEAR(fnames[i1]);
              }
            }
#endif
            for (fi = 0; fi < fcount; ++fi)
            {
              if (fnames[fi] == NULL)
                continue;
              fd = mch_fopen((char *)fnames[fi], "r");
              if (fd != NULL)
              {
                vim_fgets(IObuff, IOSIZE, fd);
                if (IObuff[0] == '*' && (s = vim_strchr(IObuff + 1, '*')) != NULL)
                {
                  int this_utf = MAYBE;

                  /* Change tag definition to a
				     * reference and remove <CR>/<NL>. */
                  IObuff[0] = '|';
                  *s = '|';
                  while (*s != NUL)
                  {
                    if (*s == '\r' || *s == '\n')
                      *s = NUL;
                    /* The text is utf-8 when a byte
					 * above 127 is found and no
					 * illegal byte sequence is found.
					 */
                    if (*s >= 0x80 && this_utf != FALSE)
                    {
                      int l;

                      this_utf = TRUE;
                      l = utf_ptr2len(s);
                      if (l == 1)
                        this_utf = FALSE;
                      s += l - 1;
                    }
                    ++s;
                  }

                  /* The help file is latin1 or utf-8;
				     * conversion to the current
				     * 'encoding' may be required. */
                  vc.vc_type = CONV_NONE;
                  convert_setup(&vc, (char_u *)(this_utf == TRUE ? "utf-8" : "latin1"), p_enc);
                  if (vc.vc_type == CONV_NONE)
                    /* No conversion needed. */
                    cp = IObuff;
                  else
                  {
                    /* Do the conversion.  If it fails
					 * use the unconverted text. */
                    cp = string_convert(&vc, IObuff,
                                        NULL);
                    if (cp == NULL)
                      cp = IObuff;
                  }
                  convert_setup(&vc, NULL, NULL);

                  ml_append(lnum, cp, (colnr_T)0, FALSE);
                  if (cp != IObuff)
                    vim_free(cp);
                  ++lnum;
                }
                fclose(fd);
              }
            }
            FreeWild(fcount, fnames);
          }
        }
        if (mustfree)
          vim_free(rt);
      }
      break;
    }
  }
}

/*
 * ":exusage"
 */
void ex_exusage(exarg_T *eap UNUSED)
{
  do_cmdline_cmd((char_u *)"help ex-cmd-index");
}

/*
 * ":viusage"
 */
void ex_viusage(exarg_T *eap UNUSED)
{
  do_cmdline_cmd((char_u *)"help normal-index");
}

/*
 * Generate tags in one help directory.
 */
static void
helptags_one(
    char_u *dir,       /* doc directory */
    char_u *ext,       /* suffix, ".txt", ".itx", ".frx", etc. */
    char_u *tagfname,  /* "tags" for English, "tags-fr" for French. */
    int add_help_tags) /* add "help-tags" tag */
{
  FILE *fd_tags;
  FILE *fd;
  garray_T ga;
  int filecount;
  char_u **files;
  char_u *p1, *p2;
  int fi;
  char_u *s;
  int i;
  char_u *fname;
  int dirlen;
  int utf8 = MAYBE;
  int this_utf8;
  int firstline;
  int mix = FALSE; /* detected mixed encodings */

  /*
     * Find all *.txt files.
     */
  dirlen = (int)STRLEN(dir);
  STRCPY(NameBuff, dir);
  STRCAT(NameBuff, "/**/*");
  STRCAT(NameBuff, ext);
  if (gen_expand_wildcards(1, &NameBuff, &filecount, &files,
                           EW_FILE | EW_SILENT) == FAIL ||
      filecount == 0)
  {
    if (!got_int)
      semsg(_("E151: No match: %s"), NameBuff);
    return;
  }

  /*
     * Open the tags file for writing.
     * Do this before scanning through all the files.
     */
  STRCPY(NameBuff, dir);
  add_pathsep(NameBuff);
  STRCAT(NameBuff, tagfname);
  fd_tags = mch_fopen((char *)NameBuff, "w");
  if (fd_tags == NULL)
  {
    semsg(_("E152: Cannot open %s for writing"), NameBuff);
    FreeWild(filecount, files);
    return;
  }

  /*
     * If using the "++t" argument or generating tags for "$VIMRUNTIME/doc"
     * add the "help-tags" tag.
     */
  ga_init2(&ga, (int)sizeof(char_u *), 100);
  if (add_help_tags || fullpathcmp((char_u *)"$VIMRUNTIME/doc",
                                   dir, FALSE, TRUE) == FPC_SAME)
  {
    if (ga_grow(&ga, 1) == FAIL)
      got_int = TRUE;
    else
    {
      s = alloc(18 + (unsigned)STRLEN(tagfname));
      if (s == NULL)
        got_int = TRUE;
      else
      {
        sprintf((char *)s, "help-tags\t%s\t1\n", tagfname);
        ((char_u **)ga.ga_data)[ga.ga_len] = s;
        ++ga.ga_len;
      }
    }
  }

  /*
     * Go over all the files and extract the tags.
     */
  for (fi = 0; fi < filecount && !got_int; ++fi)
  {
    fd = mch_fopen((char *)files[fi], "r");
    if (fd == NULL)
    {
      semsg(_("E153: Unable to open %s for reading"), files[fi]);
      continue;
    }
    fname = files[fi] + dirlen + 1;

    firstline = TRUE;
    while (!vim_fgets(IObuff, IOSIZE, fd) && !got_int)
    {
      if (firstline)
      {
        /* Detect utf-8 file by a non-ASCII char in the first line. */
        this_utf8 = MAYBE;
        for (s = IObuff; *s != NUL; ++s)
          if (*s >= 0x80)
          {
            int l;

            this_utf8 = TRUE;
            l = utf_ptr2len(s);
            if (l == 1)
            {
              /* Illegal UTF-8 byte sequence. */
              this_utf8 = FALSE;
              break;
            }
            s += l - 1;
          }
        if (this_utf8 == MAYBE) /* only ASCII characters found */
          this_utf8 = FALSE;
        if (utf8 == MAYBE) /* first file */
          utf8 = this_utf8;
        else if (utf8 != this_utf8)
        {
          semsg(_("E670: Mix of help file encodings within a language: %s"), files[fi]);
          mix = !got_int;
          got_int = TRUE;
        }
        firstline = FALSE;
      }
      p1 = vim_strchr(IObuff, '*'); /* find first '*' */
      while (p1 != NULL)
      {
        /* Use vim_strbyte() instead of vim_strchr() so that when
		 * 'encoding' is dbcs it still works, don't find '*' in the
		 * second byte. */
        p2 = vim_strbyte(p1 + 1, '*'); /* find second '*' */
        if (p2 != NULL && p2 > p1 + 1) /* skip "*" and "**" */
        {
          for (s = p1 + 1; s < p2; ++s)
            if (*s == ' ' || *s == '\t' || *s == '|')
              break;

          /*
		     * Only accept a *tag* when it consists of valid
		     * characters, there is white space before it and is
		     * followed by a white character or end-of-line.
		     */
          if (s == p2 && (p1 == IObuff || p1[-1] == ' ' || p1[-1] == '\t') && (vim_strchr((char_u *)" \t\n\r", s[1]) != NULL || s[1] == '\0'))
          {
            *p2 = '\0';
            ++p1;
            if (ga_grow(&ga, 1) == FAIL)
            {
              got_int = TRUE;
              break;
            }
            s = alloc(p2 - p1 + STRLEN(fname) + 2);
            if (s == NULL)
            {
              got_int = TRUE;
              break;
            }
            ((char_u **)ga.ga_data)[ga.ga_len] = s;
            ++ga.ga_len;
            sprintf((char *)s, "%s\t%s", p1, fname);

            /* find next '*' */
            p2 = vim_strchr(p2 + 1, '*');
          }
        }
        p1 = p2;
      }
      line_breakcheck();
    }

    fclose(fd);
  }

  FreeWild(filecount, files);

  if (!got_int)
  {
    /*
	 * Sort the tags.
	 */
    if (ga.ga_data != NULL)
      sort_strings((char_u **)ga.ga_data, ga.ga_len);

    /*
	 * Check for duplicates.
	 */
    for (i = 1; i < ga.ga_len; ++i)
    {
      p1 = ((char_u **)ga.ga_data)[i - 1];
      p2 = ((char_u **)ga.ga_data)[i];
      while (*p1 == *p2)
      {
        if (*p2 == '\t')
        {
          *p2 = NUL;
          vim_snprintf((char *)NameBuff, MAXPATHL,
                       _("E154: Duplicate tag \"%s\" in file %s/%s"),
                       ((char_u **)ga.ga_data)[i], dir, p2 + 1);
          emsg((char *)NameBuff);
          *p2 = '\t';
          break;
        }
        ++p1;
        ++p2;
      }
    }

    if (utf8 == TRUE)
      fprintf(fd_tags, "!_TAG_FILE_ENCODING\tutf-8\t//\n");

    /*
	 * Write the tags into the file.
	 */
    for (i = 0; i < ga.ga_len; ++i)
    {
      s = ((char_u **)ga.ga_data)[i];
      if (STRNCMP(s, "help-tags\t", 10) == 0)
        /* help-tags entry was added in formatted form */
        fputs((char *)s, fd_tags);
      else
      {
        fprintf(fd_tags, "%s\t/*", s);
        for (p1 = s; *p1 != '\t'; ++p1)
        {
          /* insert backslash before '\\' and '/' */
          if (*p1 == '\\' || *p1 == '/')
            putc('\\', fd_tags);
          putc(*p1, fd_tags);
        }
        fprintf(fd_tags, "*\n");
      }
    }
  }
  if (mix)
    got_int = FALSE; /* continue with other languages */

  for (i = 0; i < ga.ga_len; ++i)
    vim_free(((char_u **)ga.ga_data)[i]);
  ga_clear(&ga);
  fclose(fd_tags); /* there is no check for an error... */
}

/*
 * Generate tags in one help directory, taking care of translations.
 */
static void
do_helptags(char_u *dirname, int add_help_tags)
{
#ifdef FEAT_MULTI_LANG
  int len;
  int i, j;
  garray_T ga;
  char_u lang[2];
  char_u ext[5];
  char_u fname[8];
  int filecount;
  char_u **files;

  /* Get a list of all files in the help directory and in subdirectories. */
  STRCPY(NameBuff, dirname);
  add_pathsep(NameBuff);
  STRCAT(NameBuff, "**");
  if (gen_expand_wildcards(1, &NameBuff, &filecount, &files,
                           EW_FILE | EW_SILENT) == FAIL ||
      filecount == 0)
  {
    semsg(_("E151: No match: %s"), NameBuff);
    return;
  }

  /* Go over all files in the directory to find out what languages are
     * present. */
  ga_init2(&ga, 1, 10);
  for (i = 0; i < filecount; ++i)
  {
    len = (int)STRLEN(files[i]);
    if (len > 4)
    {
      if (STRICMP(files[i] + len - 4, ".txt") == 0)
      {
        /* ".txt" -> language "en" */
        lang[0] = 'e';
        lang[1] = 'n';
      }
      else if (files[i][len - 4] == '.' && ASCII_ISALPHA(files[i][len - 3]) && ASCII_ISALPHA(files[i][len - 2]) && TOLOWER_ASC(files[i][len - 1]) == 'x')
      {
        /* ".abx" -> language "ab" */
        lang[0] = TOLOWER_ASC(files[i][len - 3]);
        lang[1] = TOLOWER_ASC(files[i][len - 2]);
      }
      else
        continue;

      /* Did we find this language already? */
      for (j = 0; j < ga.ga_len; j += 2)
        if (STRNCMP(lang, ((char_u *)ga.ga_data) + j, 2) == 0)
          break;
      if (j == ga.ga_len)
      {
        /* New language, add it. */
        if (ga_grow(&ga, 2) == FAIL)
          break;
        ((char_u *)ga.ga_data)[ga.ga_len++] = lang[0];
        ((char_u *)ga.ga_data)[ga.ga_len++] = lang[1];
      }
    }
  }

  /*
     * Loop over the found languages to generate a tags file for each one.
     */
  for (j = 0; j < ga.ga_len; j += 2)
  {
    STRCPY(fname, "tags-xx");
    fname[5] = ((char_u *)ga.ga_data)[j];
    fname[6] = ((char_u *)ga.ga_data)[j + 1];
    if (fname[5] == 'e' && fname[6] == 'n')
    {
      /* English is an exception: use ".txt" and "tags". */
      fname[4] = NUL;
      STRCPY(ext, ".txt");
    }
    else
    {
      /* Language "ab" uses ".abx" and "tags-ab". */
      STRCPY(ext, ".xxx");
      ext[1] = fname[5];
      ext[2] = fname[6];
    }
    helptags_one(dirname, ext, fname, add_help_tags);
  }

  ga_clear(&ga);
  FreeWild(filecount, files);

#else
  /* No language support, just use "*.txt" and "tags". */
  helptags_one(dirname, (char_u *)".txt", (char_u *)"tags", add_help_tags);
#endif
}

static void
helptags_cb(char_u *fname, void *cookie)
{
  do_helptags(fname, *(int *)cookie);
}

/*
 * ":helptags"
 */
void ex_helptags(exarg_T *eap)
{
  expand_T xpc;
  char_u *dirname;
  int add_help_tags = FALSE;

  /* Check for ":helptags ++t {dir}". */
  if (STRNCMP(eap->arg, "++t", 3) == 0 && VIM_ISWHITE(eap->arg[3]))
  {
    add_help_tags = TRUE;
    eap->arg = skipwhite(eap->arg + 3);
  }

  if (STRCMP(eap->arg, "ALL") == 0)
  {
    do_in_path(p_rtp, (char_u *)"doc", DIP_ALL + DIP_DIR,
               helptags_cb, &add_help_tags);
  }
  else
  {
    ExpandInit(&xpc);
    xpc.xp_context = EXPAND_DIRECTORIES;
    dirname = ExpandOne(&xpc, eap->arg, NULL,
                        WILD_LIST_NOTFOUND | WILD_SILENT, WILD_EXPAND_FREE);
    if (dirname == NULL || !mch_isdir(dirname))
      semsg(_("E150: Not a directory: %s"), eap->arg);
    else
      do_helptags(dirname, add_help_tags);
    vim_free(dirname);
  }
}

/*
 * ":drop"
 * Opens the first argument in a window.  When there are two or more arguments
 * the argument list is redefined.
 */
void ex_drop(exarg_T *eap)
{
  int split = FALSE;
  win_T *wp;
  buf_T *buf;
  tabpage_T *tp;

  /*
     * Check if the first argument is already being edited in a window.  If
     * so, jump to that window.
     * We would actually need to check all arguments, but that's complicated
     * and mostly only one file is dropped.
     * This also ignores wildcards, since it is very unlikely the user is
     * editing a file name with a wildcard character.
     */
  set_arglist(eap->arg);

  /*
     * Expanding wildcards may result in an empty argument list.  E.g. when
     * editing "foo.pyc" and ".pyc" is in 'wildignore'.  Assume that we
     * already did an error message for this.
     */
  if (ARGCOUNT == 0)
    return;

  if (cmdmod.tab)
  {
    /* ":tab drop file ...": open a tab for each argument that isn't
	 * edited in a window yet.  It's like ":tab all" but without closing
	 * windows or tabs. */
    ex_all(eap);
  }
  else
  {
    /* ":drop file ...": Edit the first argument.  Jump to an existing
	 * window if possible, edit in current window if the current buffer
	 * can be abandoned, otherwise open a new window. */
    buf = buflist_findnr(ARGLIST[0].ae_fnum);

    FOR_ALL_TAB_WINDOWS(tp, wp)
    {
      if (wp->w_buffer == buf)
      {
        goto_tabpage_win(tp, wp);
        curwin->w_arg_idx = 0;
        return;
      }
    }

    /*
	 * Check whether the current buffer is changed. If so, we will need
	 * to split the current window or data could be lost.
	 * Skip the check if the 'hidden' option is set, as in this case the
	 * buffer won't be lost.
	 */
    if (!buf_hide(curbuf))
    {
      ++emsg_off;
      split = check_changed(curbuf, CCGD_AW | CCGD_EXCMD);
      --emsg_off;
    }

    /* Fake a ":sfirst" or ":first" command edit the first argument. */
    if (split)
    {
      eap->cmdidx = CMD_sfirst;
      eap->cmd[0] = 's';
    }
    else
      eap->cmdidx = CMD_first;
    ex_rewind(eap);
  }
}

/*
 * Skip over the pattern argument of ":vimgrep /pat/[g][j]".
 * Put the start of the pattern in "*s", unless "s" is NULL.
 * If "flags" is not NULL put the flags in it: VGR_GLOBAL, VGR_NOJUMP.
 * If "s" is not NULL terminate the pattern with a NUL.
 * Return a pointer to the char just past the pattern plus flags.
 */
char_u *
skip_vimgrep_pat(char_u *p, char_u **s, int *flags)
{
  int c;

  if (vim_isIDc(*p))
  {
    /* ":vimgrep pattern fname" */
    if (s != NULL)
      *s = p;
    p = skiptowhite(p);
    if (s != NULL && *p != NUL)
      *p++ = NUL;
  }
  else
  {
    /* ":vimgrep /pattern/[g][j] fname" */
    if (s != NULL)
      *s = p + 1;
    c = *p;
    p = skip_regexp(p + 1, c, TRUE, NULL);
    if (*p != c)
      return NULL;

    /* Truncate the pattern. */
    if (s != NULL)
      *p = NUL;
    ++p;

    /* Find the flags */
    while (*p == 'g' || *p == 'j')
    {
      if (flags != NULL)
      {
        if (*p == 'g')
          *flags |= VGR_GLOBAL;
        else
          *flags |= VGR_NOJUMP;
      }
      ++p;
    }
  }
  return p;
}

#if defined(FEAT_EVAL) || defined(PROTO)
/*
 * List v:oldfiles in a nice way.
 */
void ex_oldfiles(exarg_T *eap UNUSED)
{
  list_T *l = get_vim_var_list(VV_OLDFILES);
  listitem_T *li;
  int nr = 0;
  char_u *fname;

  if (l == NULL)
    msg(_("No old files"));
  else
  {
    msg_start();
    msg_scroll = TRUE;
    for (li = l->lv_first; li != NULL && !got_int; li = li->li_next)
    {
      ++nr;
      fname = tv_get_string(&li->li_tv);
      if (!message_filtered(fname))
      {
        msg_outnum((long)nr);
        msg_puts(": ");
        msg_outtrans(fname);
        msg_clr_eos();
        msg_putchar('\n');
        ui_breakcheck();
      }
    }

    /* Assume "got_int" was set to truncate the listing. */
    got_int = FALSE;

#ifdef FEAT_BROWSE_CMD
    if (cmdmod.browse)
    {
      quit_more = FALSE;
      nr = prompt_for_number(FALSE);
      msg_starthere();
      if (nr > 0)
      {
        char_u *p = list_find_str(get_vim_var_list(VV_OLDFILES),
                                  (long)nr);

        if (p != NULL)
        {
          p = expand_env_save(p);
          eap->arg = p;
          eap->cmdidx = CMD_edit;
          cmdmod.browse = FALSE;
          do_exedit(eap, NULL);
          vim_free(p);
        }
      }
    }
#endif
  }
}
#endif
