util.c

   1 /*
   2  * (C)opyright MMVI Anselm R. Garbe <garbeam at gmail dot com>
   3  * See LICENSE file for license details.
   4  */
   5 #include "dwm.h"
   6 #include <stdarg.h>
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <sys/wait.h>
  10 #include <unistd.h>
  11
  12 /* extern */
  13
  14 void *
  15 emallocz(unsigned int size)
  16 {
  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 {
  27         va_list ap;
  28
  29         va_start(ap, errstr);
  30         vfprintf(stderr, errstr, ap);
  31         va_end(ap);
  32         exit(EXIT_FAILURE);
  33 }
  34
  35 void *
  36 erealloc(void *ptr, unsigned int size)
  37 {
  38         void *res = realloc(ptr, size);
  39         if(!res)
  40                 eprint("fatal: could not malloc() %u bytes\n", size);
  41         return res;
  42 }
  43
  44 void
  45 spawn(Arg *arg)
  46 {
  47         static char *shell = NULL;
  48
  49         if(!shell && !(shell = getenv("SHELL")))
  50                 shell = "/bin/sh";
  51
  52         if(!arg->cmd)
  53                 return;
  54         /* the double-fork construct avoids zombie processes */
  55         if(fork() == 0) {
  56                 if(fork() == 0) {
  57                         if(dpy)
  58                                 close(ConnectionNumber(dpy));
  59                         setsid();
  60                         execl(shell, shell, "-c", arg->cmd, (char *)NULL);
  61                         fprintf(stderr, "dwm: execl '%s -c %s'", shell, arg->cmd);
  62                         perror(" failed");
  63                 }
  64                 exit(0);
  65         }
  66         wait(0);
  67 }