From 036f467d0718daefe907670f10af7b92117be789 Mon Sep 17 00:00:00 2001
From: Ivana Hutarova Varekova <varekova@redhat.com>
Date: Wed, 10 Nov 2010 16:08:20 +0100
Subject: [PATCH] This patch adds help option to cgcreate tool and unified the
 cgget error messages

CHANGELOG v1:
* fix the typo (thanks jsafrane)

Signed-off-by: Ivana Hutarova Varekova<varekova@redhat.com>
Acked-by: Dhaval Giani <dhaval.giani@gmail.com>
Signed-off-by: Jan Safranek <jsafrane@redhat.com>
---
 doc/man/cgcreate.1   |  7 +++++--
 src/tools/cgcreate.c | 47 ++++++++++++++++++++++++++++++++++++--------
 2 files changed, 44 insertions(+), 10 deletions(-)

diff --git a/doc/man/cgcreate.1 b/doc/man/cgcreate.1
index 2d444ef4..d8e0449d 100644
--- a/doc/man/cgcreate.1
+++ b/doc/man/cgcreate.1
@@ -5,8 +5,8 @@
 cgcreate \- create new cgroup(s)
 
 .SH SYNOPSIS
-\fBcgcreate\fR [\fB-t\fR <\fItuid>:<tgid\fR>] [\fB-a\fR <\fIagid>:<auid\fR>] 
-\fB-g\fR <\fIcontrollers>:<path\fR> [-g ...]
+\fBcgcreate\fR [\fB-h\fR] [\fB-t\fR <\fItuid>:<tgid\fR>]
+[\fB-a\fR <\fIagid>:<auid\fR>] \fB-g\fR <\fIcontrollers>:<path\fR> [-g ...]
 
 .SH DESCRIPTION
 The command creates new cgroup(s) defined by option 
@@ -34,6 +34,9 @@ defines control groups which will be added.
 in the given controllers list. This option can be specified
 multiple times.
 
+.TP
+.B -h, --help
+display this help and exit
 
 .SH FILES
 
diff --git a/src/tools/cgcreate.c b/src/tools/cgcreate.c
index 435df4a0..c79183ee 100644
--- a/src/tools/cgcreate.c
+++ b/src/tools/cgcreate.c
@@ -24,8 +24,33 @@
 #include <errno.h>
 #include <unistd.h>
 #include <grp.h>
+#include <getopt.h>
 
 #include "tools-common.h"
+/*
+ * Display the usage
+ */
+static void usage(int status, const char *program_name)
+{
+	if (status != 0) {
+		fprintf(stderr, "Wrong input parameters,"
+			" try %s -h' for more information.\n",
+			program_name);
+	} else {
+		fprintf(stdout, "Usage: %s [-h] [-t <tuid>:<tgid>] "\
+			"[-a <agid>:<auid>] -g <controllers>:<path> [-g ...]\n",
+			program_name);
+		fprintf(stdout, "  -t <tuid>:<tgid>		Set "\
+			"the task permission\n");
+		fprintf(stdout, "  -a <tuid>:<tgid>		Set "\
+			"the admin permission\n");
+		fprintf(stdout, "  -g <controllers>:<path>	Control "\
+			"group which should be added\n");
+		fprintf(stdout, "  -h,--help			Display "\
+			"this help\n");
+	}
+}
+
 
 int main(int argc, char *argv[])
 {
@@ -33,6 +58,14 @@ int main(int argc, char *argv[])
 	int i, j;
 	int c;
 
+	static struct option long_opts[] = {
+		{"help", no_argument, NULL, 'h'},
+		{"task", required_argument, NULL, 't'},
+		{"admin", required_argument, NULL, 'a'},
+		{"", required_argument, NULL, 'g'},
+		{0, 0, 0, 0},
+	};
+
 	/* Structure to get GID from group name */
 	struct group *grp = NULL;
 	char *grp_string = NULL;
@@ -53,10 +86,7 @@ int main(int argc, char *argv[])
 
 	/* no parametr on input */
 	if (argc < 2) {
-		fprintf(stderr, "Usage is %s "
-			"-t <tuid>:<tgid> -a <agid>:<auid> "
-			"-g <list of controllers>:<relative path to cgroup>\n",
-			argv[0]);
+		usage(1, argv[0]);
 		return -1;
 	}
 	cgroup_list = calloc(capacity, sizeof(struct cgroup_group_spec *));
@@ -66,8 +96,11 @@ int main(int argc, char *argv[])
 	}
 
 	/* parse arguments */
-	while ((c = getopt(argc, argv, "a:t:g:")) > 0) {
+	while ((c = getopt_long(argc, argv, "a:t:g:h", long_opts, NULL)) > 0) {
 		switch (c) {
+		case 'h':
+			usage(0, argv[0]);
+			return 0;
 		case 'a':
 			/* set admin uid/gid */
 			if (optarg[0] == ':')
@@ -146,9 +179,7 @@ int main(int argc, char *argv[])
 			}
 			break;
 		default:
-			fprintf(stderr, "%s: "
-				"invalid command line option\n",
-				argv[0]);
+			usage(1, argv[0]);
 			return -1;
 			break;
 		}
-- 
2.47.2