util.c

   1 /* © 2004-2007 Anselm R. Garbe <garbeam at gmail dot com>
   2  * See LICENSE file for license details. */
   3 #include "dwm.h"
   4 #include <stdarg.h>
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <sys/wait.h>
   8 #include <unistd.h>
   9
  10 /* extern */
  11
  12 void *
  13 emallocz(unsigned int size) {
  14         void *res = calloc(1, size);
  15
  16         if(!res)
  17                 eprint("fatal: could not malloc() %u bytes\n", size);
  18         return res;
  19 }
  20
  21 void
  22 eprint(const char *errstr, ...) {
  23         va_list ap;
  24
  25         va_start(ap, errstr);
  26         vfprintf(stderr, errstr, ap);
  27         va_end(ap);
  28         exit(EXIT_FAILURE);
  29 }
  30
  31 void
  32 spawn(const char *arg) {
  33         static char *shell = NULL;
  34
  35         if(!shell && !(shell = getenv("SHELL")))
  36                 shell = "/bin/sh";
  37         if(!arg)
  38                 return;
  39         /* The double-fork construct avoids zombie processes and keeps the code
  40          * clean from stupid signal handlers. */
  41         if(fork() == 0) {
  42                 if(fork() == 0) {
  43                         if(dpy)
  44                                 close(ConnectionNumber(dpy));
  45                         setsid();
  46                         execl(shell, shell, "-c", arg, (char *)NULL);
  47                         fprintf(stderr, "dwm: execl '%s -c %s'", shell, arg);
  48                         perror(" failed");
  49                 }
  50                 exit(0);
  51         }
  52         wait(0);
  53 }