qLibc

qsystem.c
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1/******************************************************************************
2 * qLibc
3 *
4 * Copyright (c) 2010-2015 Seungyoung Kim.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright notice,
11 * this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright notice,
13 * this list of conditions and the following disclaimer in the documentation
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15 *
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28
29/**
30 * @file qsystem.c System APIs.
31 */
32
33#include <stdio.h>
34#include <stdlib.h>
35#include <stdbool.h>
36#include <string.h>
37#include <unistd.h>
38#include <netdb.h>
39#include <sys/socket.h>
40#include <netinet/in.h>
41#include <arpa/inet.h>
42#include "qinternal.h"
43#include "utilities/qfile.h"
44#include "utilities/qsystem.h"
45
46/**
47 * Get system environment variable
48 *
49 * @param envname environment name
50 * @param defstr if not found, return this string
51 *
52 * @return a pointer of environment variable
53 */
54 const char *qgetenv(const char *envname, const char *defstr) {
55 const char *envstr = getenv(envname);
56 return (envstr) ? envstr : defstr;
57}
58
59/**
60 * Get the result string of external command execution
61 *
62 * @param cmd external command
63 *
64 * @return malloced string pointer which contains result if successful,
65 * otherwise returns NULL
66 *
67 * @note
68 * If the command does not report result but it is executed successfully,
69 * this will returns empty string(not null)
70 */
71 char *qsyscmd(const char *cmd) {
72 FILE *fp = popen(cmd, "r");
73 if (fp == NULL)
74 return NULL;
75 char *str = qfile_read(fp, NULL);
76 pclose(fp);
77
78 if (str == NULL)
79 str = strdup("");
80 return str;
81}
82
qfile_read
void * qfile_read(FILE *fp, size_t *nbytes)
Read data from a file stream.
Definition qfile.c:214
cmd
static void * cmd(qhttpclient_t *client, const char *method, const char *uri, void *data, size_t size, int *rescode, size_t *contentslength, qlisttbl_t *reqheaders, qlisttbl_t *resheaders)
qhttpclient->cmd(): Sends a custom request(method) to the remote host and reads it's response.
Definition qhttpclient.c:1099
qgetenv
const char * qgetenv(const char *envname, const char *defstr)
Get system environment variable.
Definition qsystem.c:54
qsyscmd
char * qsyscmd(const char *cmd)
Get the result string of external command execution.
Definition qsystem.c:71