[hackers] [slock] simplify post-lock cmd and die if it fails || NRK

From: <git_AT_suckless.org>
Date: Sun, 9 Mar 2025 10:10:29 +0100 (CET)

commit a70d5d2429abf8dcb70a8817990975dc9a621d27
Author: NRK <nrk_AT_disroot.org>
AuthorDate: Fri Sep 9 14:50:12 2022 +0600
Commit: Hiltjo Posthuma <hiltjo_AT_codemadness.org>
CommitDate: Sun Mar 9 10:02:34 2025 +0100

    simplify post-lock cmd and die if it fails
    
    this patch does two things:
    
    0. simplify the code by using posix_spawn()
    1. unify the behavior of what happens if the post-lock cmd fails.
    
    currently, if `fork()` fails, slock will die without locking the screen.
    HOWEVER if `execvp()` fails it prints a message to stderr (which the
    user cannot see since the screen has been locked already) and only exits
    the child while the parent locks the screen.
    
    to reproduce:
    
            # slock some_bin_that_doesnt_exist
    
    this behavior is inconsistent, if the idea is that post-lock cmd is
    _not_ important then we shouldn't `die()` on `fork()` failure either.
    and if we assume that the post-lock cmd _is_ important, then we should
    die on exec failure as well.
    
    this patch assumes the latter and calls `die()` if `posix_spawn()`
    fails.

diff --git a/slock.c b/slock.c
index b2f14e3..b5a9b04 100644
--- a/slock.c
+++ b/slock.c
_AT_@ -13,6 +13,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>
+#include <spawn.h>
 #include <sys/types.h>
 #include <X11/extensions/Xrandr.h>
 #include <X11/keysym.h>
_AT_@ -376,15 +377,12 @@ main(int argc, char **argv) {
 
         /* run post-lock command */
         if (argc > 0) {
- switch (fork()) {
- case -1:
- die("slock: fork failed: %s\n", strerror(errno));
- case 0:
- if (close(ConnectionNumber(dpy)) < 0)
- die("slock: close: %s\n", strerror(errno));
- execvp(argv[0], argv);
- fprintf(stderr, "slock: execvp %s: %s\n", argv[0], strerror(errno));
- _exit(1);
+ pid_t pid;
+ extern char **environ;
+ int err = posix_spawnp(&pid, argv[0], NULL, NULL, argv, environ);
+ if (err) {
+ die("slock: failed to execute post-lock command: %s: %s\n",
+ argv[0], strerror(err));
                 }
         }
 
Received on Sun Mar 09 2025 - 10:10:29 CET