1/* (C)opyright MMVI-MMVII Anselm R. Garbe <garbeam at gmail dot com>
 2 * See LICENSE file for license details.
 3 */
 4#include "dwm.h"
 5#include <stdarg.h>
 6#include <stdio.h>
 7#include <stdlib.h>
 8#include <sys/wait.h>
 9#include <unistd.h>
10
11/* extern */
12
13void *
14emallocz(unsigned int size) {
15	void *res = calloc(1, size);
16
17	if(!res)
18		eprint("fatal: could not malloc() %u bytes\n", size);
19	return res;
20}
21
22void
23eprint(const char *errstr, ...) {
24	va_list ap;
25
26	va_start(ap, errstr);
27	vfprintf(stderr, errstr, ap);
28	va_end(ap);
29	exit(EXIT_FAILURE);
30}
31
32void
33spawn(Arg *arg) {
34	static char *shell = NULL;
35
36	if(!shell && !(shell = getenv("SHELL")))
37		shell = "/bin/sh";
38	if(!arg->cmd)
39		return;
40	/* The double-fork construct avoids zombie processes and keeps the code
41	 * clean from stupid signal handlers. */
42	if(fork() == 0) {
43		if(fork() == 0) {
44			if(dpy)
45				close(ConnectionNumber(dpy));
46			setsid();
47			execl(shell, shell, "-c", arg->cmd, (char *)NULL);
48			fprintf(stderr, "dwm: execl '%s -c %s'", shell, arg->cmd);
49			perror(" failed");
50		}
51		exit(0);
52	}
53	wait(0);
54}