pivot_root: add version & help option

Including other necessary changes to usage().

Signed-off-by: Sami Kerola <kerolasa@iki.fi>

1 files changed, 50 insertions, 10 deletions

diff --git a/sys-utils/pivot_root.c b/sys-utils/pivot_root.c
index f2a6f4834..8669748a1 100644
--- a/sys-utils/pivot_root.c
+++ b/sys-utils/pivot_root.c
@@ -13,21 +13,61 @@
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  */
+#include <err.h>
+#include <errno.h>
+#include <getopt.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <sys/syscall.h>
 #include <unistd.h>
 
+#include "c.h"
+#include "nls.h"
+
 #define pivot_root(new_root,put_old) syscall(SYS_pivot_root,new_root,put_old)
 
-int main(int argc, const char **argv)
+static void __attribute__ ((__noreturn__)) usage(FILE * out)
 {
-	if (argc != 3) {
-		fprintf(stderr, "usage: %s new_root put_old\n", argv[0]);
-		return 1;
-	}
-	if (pivot_root(argv[1], argv[2]) < 0) {
-		perror("pivot_root");
-		return 1;
-	}
-	return 0;
+	fprintf(out, USAGE_HEADER);
+	fprintf(out, _(" %s [options] new_root put_old\n"),
+		program_invocation_short_name);
+	fprintf(out, USAGE_HELP);
+	fprintf(out, USAGE_VERSION);
+	fprintf(out, USAGE_BEGIN_TAIL);
+	fprintf(out, USAGE_MAN_TAIL, "pivot_root(8)");
+	exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
+}
+
+int main(int argc, char **argv)
+{
+	int ch;
+	static const struct option longopts[] = {
+		{"version", no_argument, NULL, 'V'},
+		{"help", no_argument, NULL, 'h'},
+		{NULL, 0, NULL, 0}
+	};
+
+	setlocale(LC_ALL, "");
+	bindtextdomain(PACKAGE, LOCALEDIR);
+	textdomain(PACKAGE);
+
+	while ((ch = getopt_long(argc, argv, "Vh", longopts, NULL)) != -1)
+		switch (ch) {
+		case 'V':
+			printf(UTIL_LINUX_VERSION);
+			return EXIT_SUCCESS;
+		case 'h':
+			usage(stdout);
+		default:
+			usage(stderr);
+		}
+
+	if (argc != 3)
+		usage(stderr);
+
+	if (pivot_root(argv[1], argv[2]) < 0)
+		err(EXIT_FAILURE, _("failed to change root from `%s' to `%s'"),
+		    argv[1], argv[2]);
+
+	return EXIT_SUCCESS;
 }