cgconfig: change function usage behavior

remove exit from function usage and add a structure like usage function
in the other tools.
This is suggested by Ivana Hutarova Varekova <varekova@redhat.com>

now usage willn't exit, so we should help it in err case.

v4:
 - fix some code style reported by checkpatch.pl

Signed-off-by: Libo Chen <clbchenlibo.chen@huawei.com>
Acked-by: Ivana Hutarova Varekova <varekova@redhat.com>

diff --git a/src/tools/cgconfig.c b/src/tools/cgconfig.c
index 8dd1e7302fdfad1c4e365f8b207e40ba7a1aad30..5f19f70828b8754f38d79c57ea09e8ec36eb0033 100644 (file)
--- a/src/tools/cgconfig.c
+++ b/src/tools/cgconfig.c
@@ -35,29 +35,34 @@
 
 static struct cgroup_string_list cfg_files;
 
-static void usage(char *progname)
+static void usage(int status, char *progname)
 {
-       printf("Usage: %s [-h] [-f mode] [-d mode] [-s mode] "\
+       if (status != 0) {
+               fprintf(stderr, "Wrong input parameters, "\
+                       "try %s -h' for more information.\n", progname);
+       } else {
+               printf("Usage: %s [-h] [-f mode] [-d mode] [-s mode] "\
                        "[-t <tuid>:<tgid>] [-a <agid>:<auid>] "\
                        "[-l FILE] [-L DIR] ...\n", basename(progname));
-       printf("Parse and load the specified cgroups configuration file\n");
-       printf("\n");
-       printf("  -h, --help                    Display this help\n");
-       printf("  -l, --load=FILE               Parse and load the cgroups"\
-                       " configuration file\n");
-       printf("  -L, --load-directory=DIR      Parse and load the cgroups"\
-                       " configuration files from a directory\n");
-       printf("  -a <tuid>:<tgid>              Default owner of groups files"\
-                       " and directories\n");
-       printf("  -d, --dperm=mode              Default group directory"\
-                       " permissions\n");
-       printf("  -f, --fperm=mode              Default group file"\
-                       " permissions\n");
-       printf("  -s, --tperm=mode              Default tasks file"
-                       " permissions\n");
-       printf("  -t <tuid>:<tgid>              Default owner of the tasks "
-                       "file\n");
-       exit(2);
+               printf("Parse and load the specified cgroups "\
+                       "configuration file\n");
+               printf("\n");
+               printf("  -h, --help                    Display this help\n");
+               printf("  -l, --load=FILE               Parse and load "\
+                       "the cgroups configuration file\n");
+               printf("  -L, --load-directory=DIR      Parse and load "\
+                       "the cgroups configuration files from a directory\n");
+               printf("  -a <tuid>:<tgid>              Default owner of "\
+                       "groups files and directories\n");
+               printf("  -d, --dperm=mode              Default group "\
+                       "directory permissions\n");
+               printf("  -f, --fperm=mode              Default group file "\
+                       "permissions\n");
+               printf("  -s, --tperm=mode              Default tasks file "\
+                       "permissions\n");
+               printf("  -t <tuid>:<tgid>              Default owner of "\
+                       "the tasks file\n");
+       }
 }
 
 int main(int argc, char *argv[])
@@ -86,8 +91,10 @@ int main(int argc, char *argv[])
 
        cgroup_set_default_logger(-1);
 
-       if (argc < 2)
-               usage(argv[0]); /* usage() exits */
+       if (argc < 2) {
+               usage(1, argv[0]);
+               return -1;
+       }
 
        error = cgroup_string_list_init(&cfg_files, argc/2);
        if (error)
@@ -97,8 +104,9 @@ int main(int argc, char *argv[])
                        NULL)) > 0) {
                switch (c) {
                case 'h':
-                       usage(argv[0]);
-                       break;
+                       usage(0, argv[0]);
+                       error = 0;
+                       goto err;
                case 'l':
                        error = cgroup_string_list_add_item(&cfg_files, optarg);
                        if (error) {
@@ -142,8 +150,9 @@ int main(int argc, char *argv[])
                                goto err;
                        break;
                default:
-                       usage(argv[0]);
-                       break;
+                       usage(1, argv[0]);
+                       error = -1;
+                       goto err;
                }
        }