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/* Formatted system() which returns actual return status of command
*
* Copyright (c) 2021 Joachim Wiberg <troglobit@gmail.com>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/**
* @file systemf.c
* @author Joachim Wiberg
* @date 2021
* @copyright ISC License
*/
#include <errno.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/wait.h>
/**
* Like system(), but takes a formatted string as argument.
* @param fmt printf style format list to command to run
*
* This system() wrapper greatly simplifies operations that usually
* consist of composing a command from parts into a dynamic buffer
* before calling it. The return value from system() is also parsed,
* checking for proper exit and signals.
*
* @returns If the command exits normally, the return code of the command
* is returned. Otherwise, if the command is signalled, the return code
* is -1 and @a errno is set to @c EINTR.
*/
int systemf(const char *fmt, ...)
{
va_list ap;
char *cmd;
int len;
int rc;
va_start(ap, fmt);
len = vsnprintf(NULL, 0, fmt, ap);
va_end(ap);
cmd = alloca(++len);
if (!cmd) {
errno = ENOMEM;
return -1;
}
va_start(ap, fmt);
vsnprintf(cmd, len, fmt, ap);
va_end(ap);
rc = system(cmd);
if (rc == -1)
return -1;
if (WIFEXITED(rc)) {
errno = 0;
rc = WEXITSTATUS(rc);
} else if (WIFSIGNALED(rc)) {
errno = EINTR;
rc = -1;
}
return rc;
}
/**
* Local Variables:
* indent-tabs-mode: t
* c-file-style: "linux"
* End:
*/
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