cli: Implement help command

Signed-off-by: Vijay Bellur <vijay@gluster.com>
Signed-off-by: Anand V. Avati <avati@dev.gluster.com>

BUG: 1229 ()
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=1229

8 files changed, 94 insertions, 32 deletions

diff --git a/cli/src/cli-cmd-log.c b/cli/src/cli-cmd-log.c
index 9b905965d..0365f57cb 100644
--- a/cli/src/cli-cmd-log.c
+++ b/cli/src/cli-cmd-log.c
@@ -46,10 +46,11 @@ cli_cmd_log_cbk (struct cli_state *state, struct cli_cmd_word *word,
 }
 
 struct cli_cmd cli_log_cmds[] = {
-        { "log [VOLNAME] ...",
-          cli_cmd_log_cbk },
+        { "log <VOLNAME> ...",
+          cli_cmd_log_cbk,
+          "set log level for <VOLNAME>"},
 
-        { NULL, NULL }
+        { NULL, NULL, NULL }
 };
 
 
@@ -60,7 +61,8 @@ cli_cmd_log_register (struct cli_state *state)
         struct cli_cmd *cmd = NULL;
 
         for (cmd = cli_log_cmds; cmd->pattern; cmd++) {
-                ret = cli_cmd_register (&state->tree, cmd->pattern, cmd->cbk);
+                ret = cli_cmd_register (&state->tree, cmd->pattern, cmd->cbk,
+                                        cmd->desc);
                 if (ret)
                         goto out;
         }
diff --git a/cli/src/cli-cmd-misc.c b/cli/src/cli-cmd-misc.c
index 9e78ca607..1c99bf930 100644
--- a/cli/src/cli-cmd-misc.c
+++ b/cli/src/cli-cmd-misc.c
@@ -37,6 +37,11 @@ extern struct rpc_clnt *global_rpc;
 
 extern rpc_clnt_prog_t *cli_rpc_prog;
 
+extern struct cli_cmd volume_cmds[];
+extern struct cli_cmd cli_probe_cmds[];
+extern struct cli_cmd cli_log_cmds[];
+struct cli_cmd cli_misc_cmds[];
+
 int
 cli_cmd_quit_cbk (struct cli_state *state, struct cli_cmd_word *word,
                    const char **words, int wordcount)
@@ -44,12 +49,40 @@ cli_cmd_quit_cbk (struct cli_state *state, struct cli_cmd_word *word,
         exit (0);
 }
 
+int
+cli_cmd_display_help (struct cli_state *state, struct cli_cmd_word *in_word,
+                      const char **words, int wordcount)
+{
+        struct cli_cmd        *cmd = NULL;
+
+        for (cmd = volume_cmds; cmd->pattern; cmd++)
+                cli_out ("%s - %s", cmd->pattern, cmd->desc);
+
+        for (cmd = cli_probe_cmds; cmd->pattern; cmd++)
+                cli_out ("%s - %s", cmd->pattern, cmd->desc);
+
+        for (cmd = cli_log_cmds; cmd->pattern; cmd++)
+                cli_out ("%s - %s", cmd->pattern, cmd->desc);
+
+        for (cmd = cli_misc_cmds; cmd->pattern; cmd++)
+                cli_out ("%s - %s", cmd->pattern, cmd->desc);
+
+        if (!state->rl_enabled)
+                exit (0);
+
+        return 0;
+}
+
 struct cli_cmd cli_misc_cmds[] = {
         { "quit",
-          cli_cmd_quit_cbk },
+          cli_cmd_quit_cbk,
+          "quit"},
 
+        { "help",
+           cli_cmd_display_help,
+           "display command options"},
 
-        { NULL, NULL }
+        { NULL, NULL, NULL }
 };
 
 
@@ -60,7 +93,8 @@ cli_cmd_misc_register (struct cli_state *state)
         struct cli_cmd *cmd = NULL;
 
         for (cmd = cli_misc_cmds; cmd->pattern; cmd++) {
-                ret = cli_cmd_register (&state->tree, cmd->pattern, cmd->cbk);
+                ret = cli_cmd_register (&state->tree, cmd->pattern, cmd->cbk,
+                                        cmd->desc);
                 if (ret)
                         goto out;
         }
diff --git a/cli/src/cli-cmd-peer.c b/cli/src/cli-cmd-peer.c
index 2959444fe..b9acd344a 100644
--- a/cli/src/cli-cmd-peer.c
+++ b/cli/src/cli-cmd-peer.c
@@ -174,15 +174,18 @@ out:
 
 struct cli_cmd cli_probe_cmds[] = {
         { "peer probe <HOSTNAME> [PORT]",
-          cli_cmd_peer_probe_cbk },
+          cli_cmd_peer_probe_cbk,
+          "probe peer specified by <HOSTNAME>"},
 
         { "peer detach <HOSTNAME>",
-          cli_cmd_peer_deprobe_cbk },
+          cli_cmd_peer_deprobe_cbk,
+          "detach peer specified by <HOSTNAME>"},
 
         { "peer status",
-          cli_cmd_peer_status_cbk},
+          cli_cmd_peer_status_cbk,
+          "list status of peers"},
 
-        { NULL, NULL }
+        { NULL, NULL, NULL }
 };
 
 
@@ -193,7 +196,8 @@ cli_cmd_probe_register (struct cli_state *state)
         struct cli_cmd *cmd = NULL;
 
         for (cmd = cli_probe_cmds; cmd->pattern; cmd++) {
-                ret = cli_cmd_register (&state->tree, cmd->pattern, cmd->cbk);
+                ret = cli_cmd_register (&state->tree, cmd->pattern, cmd->cbk,
+                                        cmd->desc);
                 if (ret)
                         goto out;
         }
diff --git a/cli/src/cli-cmd-volume.c b/cli/src/cli-cmd-volume.c
index 63c154730..5a0817e12 100644
--- a/cli/src/cli-cmd-volume.c
+++ b/cli/src/cli-cmd-volume.c
@@ -437,48 +437,62 @@ cli_cmd_volume_set_transport_cbk (struct cli_state *state,
 
 struct cli_cmd volume_cmds[] = {
         { "volume info [all|<VOLNAME>]",
-          cli_cmd_volume_info_cbk },
+          cli_cmd_volume_info_cbk,
+          "list information of all volumes"},
 
         { "volume create <NEW-VOLNAME> [stripe <COUNT>] [replicate <COUNT>] <NEW-BRICK> ...",
-          cli_cmd_volume_create_cbk },
+          cli_cmd_volume_create_cbk,
+          "create a new volume of specified type with mentioned bricks"},
 
         { "volume delete <VOLNAME>",
-          cli_cmd_volume_delete_cbk },
+          cli_cmd_volume_delete_cbk,
+          "delete volume specified by <VOLNAME>"},
 
         { "volume start <VOLNAME>",
-          cli_cmd_volume_start_cbk },
+          cli_cmd_volume_start_cbk,
+          "start volume specified by <VOLNAME>"},
 
         { "volume stop <VOLNAME>",
-          cli_cmd_volume_stop_cbk },
+          cli_cmd_volume_stop_cbk,
+          "stop volume specified by <VOLNAME>"},
 
         { "volume rename <VOLNAME> <NEW-VOLNAME>",
-          cli_cmd_volume_rename_cbk },
+          cli_cmd_volume_rename_cbk,
+          "rename volume <VOLNAME> to <NEW-VOLNAME>"},
 
         { "volume add-brick <VOLNAME> [(replica <COUNT>)|(stripe <COUNT>)] <NEW-BRICK> ...",
-          cli_cmd_volume_add_brick_cbk },
+          cli_cmd_volume_add_brick_cbk,
+          "add brick to volume <VOLNAME>"},
 
         { "volume remove-brick <VOLNAME> [(replica <COUNT>)|(stripe <COUNT>)] <BRICK> ...",
-          cli_cmd_volume_remove_brick_cbk },
+          cli_cmd_volume_remove_brick_cbk,
+          "remove brick from volume <VOLNAME>"},
 
         { "volume rebalance <VOLNAME> start",
-          cli_cmd_volume_defrag_cbk },
+          cli_cmd_volume_defrag_cbk,
+          "start rebalance of volume <VOLNAME>"},
 
         { "volume rebalance <VOLNAME> stop",
-          cli_cmd_volume_defrag_cbk },
+          cli_cmd_volume_defrag_cbk,
+          "stop rebalance of volume <VOLNAME>"},
 
         { "volume rebalance <VOLNAME> status",
-          cli_cmd_volume_defrag_cbk },
+          cli_cmd_volume_defrag_cbk,
+          "rebalance status of volume <VOLNAME>"},
 
         { "volume replace-brick <VOLNAME> (<BRICK> <NEW-BRICK>)|pause|abort|start|status",
-          cli_cmd_volume_replace_brick_cbk },
+          cli_cmd_volume_replace_brick_cbk,
+          "replace-brick operations"},
 
         { "volume set-transport <VOLNAME> <TRANSPORT-TYPE> [<TRANSPORT-TYPE>] ...",
-          cli_cmd_volume_set_transport_cbk },
+          cli_cmd_volume_set_transport_cbk,
+          "set transport type for volume <VOLNAME>"},
 
         { "volume set <VOLNAME> <KEY> <VALUE>",
-          cli_cmd_volume_set_cbk },
+          cli_cmd_volume_set_cbk,
+         "set options for volume <VOLNAME>"},
 
-        { NULL, NULL }
+        { NULL, NULL, NULL }
 };
 
 
@@ -489,7 +503,8 @@ cli_cmd_volume_register (struct cli_state *state)
         struct cli_cmd *cmd = NULL;
 
         for (cmd = volume_cmds; cmd->pattern; cmd++) {
-                ret = cli_cmd_register (&state->tree, cmd->pattern, cmd->cbk);
+                ret = cli_cmd_register (&state->tree, cmd->pattern, cmd->cbk,
+                                        cmd->desc);
                 if (ret)
                         goto out;
         }
diff --git a/cli/src/cli-cmd.c b/cli/src/cli-cmd.c
index 4353cb6e7..d7a4fcd83 100644
--- a/cli/src/cli-cmd.c
+++ b/cli/src/cli-cmd.c
@@ -50,6 +50,9 @@ cli_cmd_needs_connection (struct cli_cmd_word *word)
         if (!strcasecmp ("quit", word->word))
                 return _gf_false;
 
+        if (!strcasecmp ("help", word->word))
+                return _gf_false;
+
         return _gf_true;
 }
 
diff --git a/cli/src/cli-cmd.h b/cli/src/cli-cmd.h
index d62309de2..b325cfdfc 100644
--- a/cli/src/cli-cmd.h
+++ b/cli/src/cli-cmd.h
@@ -30,6 +30,7 @@
 struct cli_cmd {
         const char     *pattern;
         cli_cmd_cbk_t  *cbk;
+        const char     *desc;
 };
 
 int cli_cmd_volume_register (struct cli_state *state);
diff --git a/cli/src/cli.h b/cli/src/cli.h
index 9efabfe58..9bc0b5094 100644
--- a/cli/src/cli.h
+++ b/cli/src/cli.h
@@ -56,6 +56,7 @@ struct cli_cmd_word {
         cli_cmd_filler_t      *filler;
         cli_cmd_match_t       *match;
         cli_cmd_cbk_t         *cbkfn;
+        const char            *desc;
 
         int                    nextwords_cnt;
         struct cli_cmd_word  **nextwords;
@@ -134,7 +135,7 @@ typedef ssize_t (*cli_serialize_t) (struct iovec outmsg, void *args);
 extern struct cli_state *global_state; /* use only in readline callback */
 
 int cli_cmd_register (struct cli_cmd_tree *tree, const char *template,
-                      cli_cmd_cbk_t cbk);
+                      cli_cmd_cbk_t cbk, const char *desc);
 int cli_cmds_register (struct cli_state *state);
 
 int cli_input_init (struct cli_state *state);
diff --git a/cli/src/registry.c b/cli/src/registry.c
index 0ced00787..f7e366fd6 100644
--- a/cli/src/registry.c
+++ b/cli/src/registry.c
@@ -318,7 +318,8 @@ cli_cmd_newword (struct cli_cmd_word *word, const char *token)
 
 
 int
-cli_cmd_ingest (struct cli_cmd_tree *tree, char **tokens, cli_cmd_cbk_t *cbkfn)
+cli_cmd_ingest (struct cli_cmd_tree *tree, char **tokens, cli_cmd_cbk_t *cbkfn,
+                const char *desc)
 {
         int                    ret = 0;
         char                 **tokenp = NULL;
@@ -349,6 +350,7 @@ cli_cmd_ingest (struct cli_cmd_tree *tree, char **tokens, cli_cmd_cbk_t *cbkfn)
         }
 
         word->cbkfn = cbkfn;
+        word->desc  = desc;
 
         /* end of static strings in command template */
 
@@ -360,7 +362,7 @@ cli_cmd_ingest (struct cli_cmd_tree *tree, char **tokens, cli_cmd_cbk_t *cbkfn)
 
 int
 cli_cmd_register (struct cli_cmd_tree *tree, const char *template,
-                  cli_cmd_cbk_t cbk)
+                  cli_cmd_cbk_t cbk, const char *desc)
 {
         char **tokens = NULL;
         int    ret = 0;
@@ -372,7 +374,7 @@ cli_cmd_register (struct cli_cmd_tree *tree, const char *template,
         if (!tokens)
                 return -1;
 
-        ret = cli_cmd_ingest (tree, tokens, cbk);
+        ret = cli_cmd_ingest (tree, tokens, cbk, desc);
         if (ret)
                 goto err;