From 19c221a82758291b81d945de3f9cf00639d7469a Mon Sep 17 00:00:00 2001
From: Ivana Hutarova Varekova <varekova@redhat.com>
Date: Thu, 28 Apr 2011 10:25:17 +0200
Subject: [PATCH] Add -h option to cgexec tool

This patch adds option -h to cgexec tool

Signed-off-by: Ivana Hutarova Varekova <varekova@redhat.com>
Signed-off-by: Jan Safranek <jsafrane@redhat.com>
---
 doc/man/cgexec.1   |  6 +++++-
 src/tools/cgexec.c | 35 ++++++++++++++++++++++-------------
 2 files changed, 27 insertions(+), 14 deletions(-)

diff --git a/doc/man/cgexec.1 b/doc/man/cgexec.1
index bf197bdb..e9d38d20 100644
--- a/doc/man/cgexec.1
+++ b/doc/man/cgexec.1
@@ -7,7 +7,7 @@
 cgexec \- run the task in given control groups
 
 .SH SYNOPSIS
-\fBcgexec\fR [\fB-g\fR <\fIcontrollers>:<path\fR>] [--sticky] \fBcommand\fR [\fIarguments\fR]
+\fBcgexec\fR [\fB-h\fR] [\fB-g\fR <\fIcontrollers>:<path\fR>] [--sticky] \fBcommand\fR [\fIarguments\fR]
 
 .SH DESCRIPTION
 The \fBcgexec\fR
@@ -31,6 +31,10 @@ If this option is not used then
 \fBcgexec\fR will automatically place the task to the right
 cgroup based on \fB/etc/cgrules.conf\fR.
 
+.TP
+.B -h, --help
+Display this help and exit.
+
 .TP
 .B --sticky
 If running the task \fBcommand\fR with this option, the daemon of
diff --git a/src/tools/cgexec.c b/src/tools/cgexec.c
index 8e0b4d8c..f03f1fa0 100644
--- a/src/tools/cgexec.c
+++ b/src/tools/cgexec.c
@@ -35,10 +35,25 @@
 #include "tools-common.h"
 
 static struct option longopts[] = {
-	{"sticky", no_argument, NULL, 's'}, 
+	{"sticky", no_argument, NULL, 's'},
+	{"help", no_argument, NULL, 'h'},
 	{0, 0, 0, 0}
 };
 
+static void usage(int status, const char *program_name)
+{
+	if (status != 0)
+		fprintf(stderr, "Wrong input parameters,"
+			" try %s --help' for more information.\n",
+			program_name);
+	else {
+		printf("Usage: %s [-h] [-g <controllers>:<path>] "
+			"[--sticky] command [arguments] ...\n",
+			program_name);
+	}
+}
+
+
 int main(int argc, char *argv[])
 {
 	int ret = 0, i;
@@ -50,17 +65,9 @@ int main(int argc, char *argv[])
 	int c;
 	struct cgroup_group_spec *cgroup_list[CG_HIER_MAX];
 
-	if (argc < 2) {
-		fprintf(stderr, "Usage is %s"
-			" [-g <list of controllers>:<relative path to cgroup>]"
-			" [--sticky] command [arguments]  \n",
-			argv[0]);
-		exit(2);
-	}
-
 	memset(cgroup_list, 0, sizeof(cgroup_list));
 
-	while ((c = getopt_long(argc, argv, "+g:s", longopts, NULL)) > 0) {
+	while ((c = getopt_long(argc, argv, "+g:sh", longopts, NULL)) > 0) {
 		switch (c) {
 		case 'g':
 			ret = parse_cgroup_spec(cgroup_list, optarg,
@@ -75,16 +82,18 @@ int main(int argc, char *argv[])
 		case 's':
 			flag_child |= CGROUP_DAEMON_UNCHANGE_CHILDREN;
 			break;
+		case 'h':
+			usage(0, argv[0]);
+			exit(0);
 		default:
-			fprintf(stderr, "Invalid command line option\n");
+			usage(1, argv[0]);
 			exit(1);
-			break;
 		}
 	}
 
 	/* Executable name */
 	if (!argv[optind]) {
-		fprintf(stderr, "No command specified\n");
+		usage(1, argv[0]);
 		exit(1);
 	}
 
-- 
2.47.2