wmfs/wmfs2/src/util.c
Martin Duquesnoy 5b5e780680 Add parser
2011-08-09 10:51:21 +02:00

105 lines
2.1 KiB
C
Executable File

/*
* wmfs2 by Martin Duquesnoy <xorg62@gmail.com> { for(i = 2011; i < 2111; ++i) ©(i); }
* For license, see COPYING.
*/
#include <stdint.h>
#include "util.h"
/** malloc with error support and size_t overflow protection
* \param nmemb number of objects
* \param size size of single object
* \return non null void pointer
*/
void*
xmalloc(size_t nmemb, size_t size)
{
void *ret;
if(SIZE_MAX / nmemb < size)
err(EXIT_FAILURE, "xmalloc(%zu, %zu), "
"size_t overflow detected", nmemb, size);
if((ret = malloc(nmemb * size)) == NULL)
err(EXIT_FAILURE, "malloc(%zu)", nmemb * size);
return ret;
}
/** calloc with error support
* \param nmemb Number of objects
* \param size size of single object
* \return non null void pointer
*/
void*
xcalloc(size_t nmemb, size_t size)
{
void *ret;
if((ret = calloc(nmemb, size)) == NULL)
err(EXIT_FAILURE, "calloc(%zu * %zu)", nmemb, size);
return ret;
}
/** asprintf wrapper
* \param strp target string
* \param fmt format
* \return non zero integer
*/
int
xasprintf(char **strp, const char *fmt, ...)
{
int ret;
va_list args;
va_start(args, fmt);
ret = vasprintf(strp, fmt, args);
va_end(args);
if (ret == -1)
err(EXIT_FAILURE, "asprintf(%s)", fmt);
return ret;
}
/** Execute a system command
* \param cmd Command
* \return child pid
*/
pid_t
spawn(const char *format, ...)
{
char *sh = NULL;
char cmd[512];
va_list ap;
pid_t pid;
size_t len;
va_start(ap, format);
len = vsnprintf(cmd, sizeof(cmd), format, ap);
va_end(ap);
if (len >= sizeof(cmd))
{
warnx("command too long (> 512 bytes)");
return -1;
}
if(!(sh = getenv("SHELL")))
sh = "/bin/sh";
if((pid = fork()) == 0)
{
setsid();
if (execl(sh, sh, "-c", cmd, (char*)NULL) == -1)
warn("execl(sh -c %s)", cmd);
exit(EXIT_FAILURE);
}
else if (pid == -1)
warn("fork");
return pid;
}