Move start_stop_daemon to debianutils.

[oweals/busybox.git] / coreutils / tty.c

diff --git a/coreutils/tty.c b/coreutils/tty.c
index f3c7fb74f5ceefb3297a839c6b170ebfd1a6da3f..cd2c784fda39a9dc21957214291a1d736eb8dea7 100644 (file)
--- a/coreutils/tty.c
+++ b/coreutils/tty.c
@@ -1,8 +1,8 @@
 /* vi: set sw=4 ts=4: */
 /*
- * Mini tty implementation for busybox
+ * tty implementation for busybox
  *
- * Copyright (C) 2000  Edward Betts <edward@debian.org>.
+ * Copyright (C) 2003  Manuel Novoa III  <mjn3@codepoet.org>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -20,31 +20,39 @@
  *
  */
 
-#include "internal.h"
-#include <stdio.h>
-#include <sys/types.h>
+/* BB_AUDIT SUSv3 compliant */
+/* http://www.opengroup.org/onlinepubs/007904975/utilities/tty.html */
 
-static const char tty_usage[] = "tty\n"
-#ifndef BB_FEATURE_TRIVIAL_HELP
-       "\nPrint the file name of the terminal connected to standard input.\n\n"
-       "Options:\n"
-       "\t-s\tprint nothing, only return an exit status\n"
-#endif
-       ;
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include "busybox.h"
 
 extern int tty_main(int argc, char **argv)
 {
-       char *tty;
-
-       if (argc > 1) {
-               if (argv[1][0] != '-' || argv[1][1] != 's')
-                       usage(tty_usage);
-       } else {
-               tty = ttyname(0);
-               if (tty)
-                       puts(tty);
-               else
-                       puts("not a tty");
+       const char *s;
+       int silent;             /* Note: No longer relevant in SUSv3. */
+       int retval;
+
+       bb_default_error_retval = 2;    /* SUSv3 requires > 1 for error. */
+
+       silent = bb_getopt_ulflags(argc, argv, "s");
+
+       /* gnu tty outputs a warning that it is ignoring all args. */
+       bb_warn_ignoring_args(argc - optind);
+
+       retval = 0;
+
+       if ((s = ttyname(0)) == NULL) {
+       /* According to SUSv3, ttyname can on fail with EBADF or ENOTTY.
+        * We know the file descriptor is good, so failure means not a tty. */
+               s = "not a tty";
+               retval = 1;
        }
-       return(isatty(0) ? TRUE : FALSE);
+
+       if (!silent) {
+               puts(s);
+       }
+
+       bb_fflush_stdout_and_exit(retval);
 }