util.c

   1 /* © 2006-2007 Anselm R. Garbe <garbeam at gmail dot com>
   2  * © 2006-2007 Sander van Dijk <a dot h dot vandijk at gmail dot com>
   3  * © 2007 Premysl Hruby <dfenze at gmail dot com>
   4  * © 2007 Szabolcs Nagy <nszabolcs at gmail dot com>
   5  * See LICENSE file for license details. */
   6 #include "dwm.h"
   7 #include <stdarg.h>
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <sys/wait.h>
  11 #include <unistd.h>
  12
  13 /* extern */
  14
  15 void *
  16 emallocz(unsigned int size) {
  17         void *res = calloc(1, size);
  18
  19         if(!res)
  20                 eprint("fatal: could not malloc() %u bytes\n", size);
  21         return res;
  22 }
  23
  24 void
  25 eprint(const char *errstr, ...) {
  26         va_list ap;
  27
  28         va_start(ap, errstr);
  29         vfprintf(stderr, errstr, ap);
  30         va_end(ap);
  31         exit(EXIT_FAILURE);
  32 }
  33
  34 void
  35 spawn(const char *arg) {
  36         static char *shell = NULL;
  37
  38         if(!shell && !(shell = getenv("SHELL")))
  39                 shell = "/bin/sh";
  40         if(!arg)
  41                 return;
  42         /* The double-fork construct avoids zombie processes and keeps the code
  43          * clean from stupid signal handlers. */
  44         if(fork() == 0) {
  45                 if(fork() == 0) {
  46                         if(dpy)
  47                                 close(ConnectionNumber(dpy));
  48                         setsid();
  49                         execl(shell, shell, "-c", arg, (char *)NULL);
  50                         fprintf(stderr, "dwm: execl '%s -c %s'", shell, arg);
  51                         perror(" failed");
  52                 }
  53                 exit(0);
  54         }
  55         wait(0);
  56 }