+
+\f
+/* Button callbacks */
+
+#ifdef VMS
+# define pid_t int
+# define fork vfork
+#endif /* VMS */
+
+static void
+fork_and_exec (saver_info *si, const char *command, const char *desc)
+{
+ saver_preferences *p = &si->prefs;
+ pid_t forked;
+ char buf [512];
+ char *av[5];
+ int ac;
+
+ if (!command || !*command)
+ {
+ fprintf (stderr, "%s: no %s command has been specified.\n",
+ blurb(), desc);
+ return;
+ }
+
+ switch ((int) (forked = fork ()))
+ {
+ case -1:
+ sprintf (buf, "%s: couldn't fork", blurb());
+ perror (buf);
+ break;
+
+ case 0:
+ close (ConnectionNumber (si->dpy)); /* close display fd */
+ hack_subproc_environment (si->default_screen); /* set $DISPLAY */
+ ac = 0;
+ av [ac++] = (char *) p->shell;
+ av [ac++] = (char *) "-c";
+ av [ac++] = (char *) command;
+ av [ac] = 0;
+ execvp (av[0], av); /* shouldn't return. */
+
+ sprintf (buf, "%s: execvp(\"%s\", \"%s\", \"%s\") failed",
+ blurb(), av[0], av[1], av[2]);
+ perror (buf);
+ fflush (stderr);
+ fflush (stdout);
+ exit (1); /* Note that this only exits a child fork. */
+ break;
+
+ default:
+ /* parent fork. */
+ break;
+ }
+}
+
+
+static void
+do_demo (saver_info *si)
+{
+ saver_preferences *p = &si->prefs;
+ fork_and_exec (si, p->demo_command, "demo-mode");
+}
+
+static void
+do_prefs (saver_info *si)
+{
+ saver_preferences *p = &si->prefs;
+ fork_and_exec (si, p->prefs_command, "preferences");
+}
+
+static void
+do_help (saver_info *si)
+{
+ saver_preferences *p = &si->prefs;
+ char *help_command;
+
+ if (!p->help_url || !*p->help_url)
+ {
+ fprintf (stderr, "%s: no Help URL has been specified.\n", blurb());
+ return;
+ }
+
+ help_command = (char *) malloc (strlen (p->load_url_command) +
+ (strlen (p->help_url) * 2) + 10);
+ sprintf (help_command, p->load_url_command, p->help_url, p->help_url);
+ fork_and_exec (si, help_command, "URL-loading");
+ free (help_command);
+}