util.c

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