use getopt() to parse options

[wall-notify/wall-notify.git] / src / wall-notify.c

diff --git a/src/wall-notify.c b/src/wall-notify.c
index 292b71a1d9d026208db979be56cc5c03bdffb4d0..bbc783b5e884514ca1f793da674ba22d71bc5415 100644 (file)
--- a/src/wall-notify.c
+++ b/src/wall-notify.c
@@ -359,23 +359,57 @@ static void *x11_event_loop_thread(void *unused) {
 #endif
 
 static void usage(const char *argv0) {
-    fprintf(stderr, "usage: %s <cmd args..>\n", argv0);
+    fprintf(stderr, "usage: %s [-X] <cmd args..>\n", argv0);
+    fprintf(stderr, "Pass wall messages to <cmd args..>.\n");
+    fprintf(stderr, "\n");
+    fprintf(stderr, "-X quit when the current X session terminates\n");
+#ifdef DONT_USE_X11
+    fprintf(stderr, "\n");
+    fprintf(stderr, "compiled without X11 support, -X disabled\n");
+#endif
     exit(EXIT_FAILURE);
 }
 
 
 int main(int argc, char **argv) {
+    int option, enable_x11;
     int ptm, pts;
     char *name;
-    const char *argv0;
 
-    argv0 = argv[0];
-    /* Don't pass our argv[0] to the notification program. */
-    argv++;
+    /* Don't display error messages for unknown options. */
+    opterr = 0;
+
+    enable_x11 = 0;
+
+    /*
+     * Glibc violates POSIX by default and skips over non-option arguments and
+     * parses later arguments which look like options as well. But we want to
+     * pass everything except the options unmodified to execvp(). Prefixing
+     * the optstring with "+" fixes this behaver. This is not POSIX
+     * compatible, but the option should be ignored on other systems.
+     */
+    while ((option = getopt(argc, argv, "+Xh")) != -1) {
+        switch (option) {
+            case 'X':
+                enable_x11 = 1;
+                break;
+            case 'h':
+                usage(argv[0]);
+                break;
+            default:
+                fprintf(stderr, "%s: unknown option '%s'!\n\n",
+                                argv[0], argv[optind - 1]);
+                usage(argv[0]);
+                break;
+        }
+    }
 
-    if (argc < 2) {
-        usage(argv0);
+    /* No arguments remaining, abort. */
+    if (!argv[optind]) {
+        usage(argv[0]);
     }
+    /* Arguments for notification program. */
+    argv += optind;
 
     ptm = open_tty();
     if (ptm < 0) {
@@ -400,18 +434,21 @@ int main(int argc, char **argv) {
         exit(EXIT_FAILURE);
     }
 
-#ifndef DONT_USE_X11
     /* Start a thread which connects to X11. This way we die if the user logs
      * out of its X11 session. */
-    {
+    if (enable_x11) {
+#ifdef DONT_USE_X11
+        fprintf(stderr, "%s: option -X is disabled!\n\n", argv0);
+        usage(argv0);
+#else
         pthread_t tid;
 
         if (pthread_create(&tid, NULL, x11_event_loop_thread, NULL) != 0) {
             perror("pthread_create");
             exit(EXIT_FAILURE);
         }
-    }
 #endif
+    }
 
     /* Cleanup on signals. Necessary before login(). */
     setup_signals();