next version will contain updated copyright notice

[dwm.git] / util.c

diff --git a/util.c b/util.c
index 3553f5d..3175ab2 100644 (file)
--- a/util.c
+++ b/util.c
@@ -1,18 +1,63 @@
-/*
- * (C)opyright MMVI Anselm R. Garbe <garbeam at gmail dot com>
+/* (C)opyright MMVII Anselm R. Garbe <garbeam at gmail dot com>
  * See LICENSE file for license details.
  */
-
+#include "dwm.h"
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+/* extern */
+
+void *
+emallocz(unsigned int size) {
+       void *res = calloc(1, size);
+
+       if(!res)
+               eprint("fatal: could not malloc() %u bytes\n", size);
+       return res;
+}
 
 void
-error(char *errstr, ...) {
+eprint(const char *errstr, ...) {
        va_list ap;
+
        va_start(ap, errstr);
        vfprintf(stderr, errstr, ap);
        va_end(ap);
-       exit(1);
+       exit(EXIT_FAILURE);
 }
 
+void *
+erealloc(void *ptr, unsigned int size) {
+       void *res = realloc(ptr, size);
+
+       if(!res)
+               eprint("fatal: could not malloc() %u bytes\n", size);
+       return res;
+}
+
+void
+spawn(Arg *arg) {
+       static char *shell = NULL;
+
+       if(!shell && !(shell = getenv("SHELL")))
+               shell = "/bin/sh";
+       if(!arg->cmd)
+               return;
+       /* The double-fork construct avoids zombie processes and keeps the code
+        * clean from stupid signal handlers. */
+       if(fork() == 0) {
+               if(fork() == 0) {
+                       if(dpy)
+                               close(ConnectionNumber(dpy));
+                       setsid();
+                       execl(shell, shell, "-c", arg->cmd, (char *)NULL);
+                       fprintf(stderr, "dwm: execl '%s -c %s'", shell, arg->cmd);
+                       perror(" failed");
+               }
+               exit(0);
+       }
+       wait(0);
+}