## NAME

flex - the fast lexical analyser generator

## SYNOPSIS

flex [,OPTIONS/] [,FILE/]...

## DESCRIPTION

Generates programs that perform pattern-matching on text.

## Table Compression:

-Ca, --align trade off larger tables for better memory alignment

-Ce, --ecs construct equivalence classes

-Cf do not compress tables; use -f representation

-CF do not compress tables; use -F representation

-Cm, --meta-ecs construct meta-equivalence classes

-Cr, --read use read() instead of stdio for scanner input

-f, --full generate fast, large scanner. Same as -Cfr

-F, --fast use alternate table representation. Same as -CFr

-Cem default compression (same as --ecs --meta-ecs)

## Debugging:

-d, --debug enable debug mode in scanner

-b, --backup write backing-up information to lex.backup

-p, --perf-report write performance report to stderr

-s, --nodefault suppress default rule to ECHO unmatched text

-T, --trace flex should run in trace mode

-w, --nowarn do not generate warnings

-v, --verbose write summary of scanner statistics to stdout

## FILES

-o, --outfile=,FILE/ specify output filename

-S, --skel=,FILE/ specify skeleton file

-t, --stdout write scanner on stdout instead of lex.yy.c

--yyclass=,NAME/ name of C++ class

--header-file=,FILE/ create a C header file in addition to the scanner

--tables-file[=,FILE/] write tables to FILE

## Scanner behavior:

-7, --7bit generate 7-bit scanner

-8, --8bit generate 8-bit scanner

-B, --batch generate batch scanner (opposite of -I)

-i, --case-insensitive ignore case in patterns

-l, --lex-compat maximal compatibility with original lex

-X, --posix-compat maximal compatibility with POSIX lex

-I, --interactive generate interactive scanner (opposite of -B)

--yylineno track line count in yylineno

## Generated code:

-+, --c++ generate C++ scanner class

-Dmacro[=,defn/] #define macro defn (default defn is '1')

-L, --noline suppress #line directives in scanner

-P, --prefix=,STRING/ use STRING as prefix instead of "yy"

-R, --reentrant generate a reentrant C scanner

--bison-bridge scanner for bison pure parser.

--bison-locations include yylloc support.

--stdinit initialize yyin/yyout to stdin/stdout

--noansi-definitions old-style function definitions

--noansi-prototypes empty parameter list in prototypes

--nounistd do not include <unistd.h>

--noFUNCTION do not generate a particular FUNCTION

## Miscellaneous:

-c do-nothing POSIX option

-n do-nothing POSIX option

-?

-h, --help produce this help message

-V, --version report flex version

## SEE ALSO

The full documentation for flex is maintained as a Texinfo manual. If the info and flex programs are properly installed at your site, the command

info flex

should give you access to the complete manual.