cgset: Change the handling of options, add --help

Change the handling of options
- add the possibility to use long options
- add --help option
- change the type of c (see man 3 getopt_long)

Signed-off-by: Ivana Varekova <varekova@redhat.com>
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>

diff --git a/src/tools/cgset.c b/src/tools/cgset.c
index 071ffac4fd2f415d7dbcd4c431a1e104969e0c89..0c153eb94920a15c31b303c308659d18d0ea7195 100644 (file)
--- a/src/tools/cgset.c
+++ b/src/tools/cgset.c
@@ -5,9 +5,18 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <getopt.h>
 
 #include "tools-common.h"
 
+static struct option const long_options[] =
+{
+       {"rule", required_argument, NULL, 'r'},
+       {"help", no_argument, NULL, 'h'},
+       {NULL, 0, NULL, 0}
+};
+
+
 struct cgroup *copy_name_value_from_rules(int nv_number,
                        struct control_value *name_value)
 {
@@ -63,11 +72,24 @@ scgroup_err:
        return NULL;
 }
 
+void usage(int status, char *program_name)
+{
+       if (status != 0)
+               fprintf(stderr, "Wrong input parameters,"
+                       " try %s --help' for more information.\n",
+                       program_name);
+       else {
+               printf("Usage: %s [-r <name=value>]  <cgroup_path> ...\n"
+                       "   or: %s --copy-from <source_cgrup_path> "
+                           "<cgroup_path> ...\n",
+                       program_name, program_name, program_name);
+       }
+}
 
 int main(int argc, char *argv[])
 {
        int ret = 0;
-       char c;
+       int c;
 
        char *buf;
        struct control_value *name_value = NULL;
@@ -86,8 +108,15 @@ int main(int argc, char *argv[])
        }
 
        /* parse arguments */
-       while ((c = getopt(argc, argv, "r:")) > 0) {
+       while ((c = getopt_long (argc, argv,
+               "r:h", long_options, NULL)) != -1) {
                switch (c) {
+               case 'h':
+                       usage(0, argv[0]);
+                       ret = 0;
+                       goto err;
+                       break;
+
                case 'r':
                        /* add name-value pair to buffer
                                (= name_value variable) */
@@ -97,8 +126,9 @@ int main(int argc, char *argv[])
                                        realloc(name_value,
                                        nv_max * sizeof(struct control_value));
                                if (!name_value) {
-                                       fprintf(stderr, "cgset: "
-                                               "not enough memory\n");
+                                       fprintf(stderr, "%s: "
+                                               "not enough memory\n",
+                                               argv[0]);
                                        ret = -1;
                                        goto err;
                                }
@@ -133,8 +163,7 @@ int main(int argc, char *argv[])
                        nv_number++;
                        break;
                default:
-                       fprintf(stderr, "%s: invalid command line option\n",
-                               argv[0]);
+                       usage(1, argv[0]);
                        ret = -1;
                        goto err;
                        break;