mount.ceph: add usage message

Signed-off-by: Colin McCabe <colinm@hq.newdream.net>

diff --git a/src/mount/mount.ceph.c b/src/mount/mount.ceph.c
index dd5a43595f15f75dfa475fb963258b14d5a5c11c..3a218c617518c9416d18011c749ea067fc3f02bf 100755 (executable)
--- a/src/mount/mount.ceph.c
+++ b/src/mount/mount.ceph.c
@@ -302,42 +302,79 @@ static char *parse_options(const char *data, int *filesys_flags)
 }
 
 
-int main(int argc, char *argv[])
+static int parse_arguments(int argc, char **argv,
+               char **src, char **node, char **opts)
 {
        int i;
-       char **new_argv;
-       char *src, *node, *opts;
-       int flags = 0;
-       int options_pos = 0;
-       int retval = 0;
 
-       if (argc < 5)
-               exit(1);
+       if (argc < 2) {
+               // There were no arguments. Just show the usage.
+               return 1;
+       }
+       if ((!strcmp(argv[1], "-h")) || (!strcmp(argv[1], "--help"))) {
+               // The user asked for help.
+               return 1;
+       }
 
-       new_argv = (char **)malloc(sizeof(char *)*argc);
-
-       for (i=0; i<argc; i++) {
-               new_argv[i] = argv[i];
-               if (strcmp(new_argv[i], "-o") == 0) {
-                       options_pos = i+1;
-                       if (options_pos >= argc) {
-                               printf("usage error\n");
-                               exit(1);
-                       }               
-               } else if (strcmp(new_argv[i], "-v") == 0) {
+       // The first two arguments are positional
+       if (argc < 3)
+               return -EINVAL;
+       *src = argv[1];
+       *node = argv[2];
+
+       // Parse the remaining options
+       *opts = NULL;
+       for (i = 3; i < argc; ++i) {
+               if (!strcmp("-h", argv[i]))
+                       return 1;
+               else if (!strcmp("-v", argv[i]))
                        verboseflag = 1;
+               else if (!strcmp("-o", argv[i])) {
+                       ++i;
+                       if (i >= argc) {
+                               printf("Option -o requires an argument.\n\n");
+                               return -EINVAL;
+                       }
+                       *opts = argv[i];
+               }
+               else {
+                       printf("Can't understand option: '%s'\n\n", argv[i]);
+                       return -EINVAL;
                }
        }
+       return 0;
+}
+
+static void usage(const char *prog_name)
+{
+       printf("usage: %s [src] [mount-point] [-v] [-o ceph-options]\n",
+               prog_name);
+       printf("options:\n");
+       printf("\t-h: Print this help\n");
+       printf("\t-v: Verbose\n");
+       printf("\tceph-options: refer to mount.ceph(8)\n");
+       printf("\n");
+}
+
+int main(int argc, char *argv[])
+{
+       char *src, *node, *opts;
+       int flags = 0;
+       int retval = 0;
+
+       retval = parse_arguments(argc, argv, &src, &node, &opts);
+       if (retval) {
+               usage(argv[0]);
+               exit((retval > 0) ? EXIT_SUCCESS : EXIT_FAILURE);
+       }
 
-       src = mount_resolve_src(argv[1]);
+       src = mount_resolve_src(src);
        if (!src) {
                printf("failed to resolve source\n");
                exit(1);
        }
 
-       node = new_argv[2];
-
-       opts = parse_options(new_argv[options_pos], &flags);
+       opts = parse_options(opts, &flags);
        if (!opts) {
                printf("failed to parse ceph_options\n");
                exit(1);
@@ -362,7 +399,6 @@ int main(int argc, char *argv[])
 
        free(opts);
        free(src);
-       free(new_argv); 
        exit(retval);
 }