added a comment to spawn

[dwm.git] / util.c

diff --git a/util.c b/util.c
index 2eb9eb2..91df00b 100644 (file)
--- a/util.c
+++ b/util.c
@@ -51,12 +51,13 @@ spawn(Arg *arg)
 
        if(!arg->cmd)
                return;
+       /* the double-fork construct avoids zombie processes */
        if(fork() == 0) {
                if(fork() == 0) {
                        if(dpy)
                                close(ConnectionNumber(dpy));
                        setsid();
-                       execl(shell, shell, "-c", arg->cmd, NULL);
+                       execl(shell, shell, "-c", arg->cmd, (char *)NULL);
                        fprintf(stderr, "dwm: execl '%s -c %s'", shell, arg->cmd);
                        perror(" failed");
                }