[PATCH 1/3] Print subcommands as a part of the usage

[Oliver O'Halloran]

This is helpful since there's no real way to discover what subcommands a
command has. Generally the usage information for the "root" of a
subcommand set isn't terribly useful anyway, so I think this is an
improvement.

Case in point, the usage information for .info is wrong since
there's no "type" subcommand:

(poke) .info
Usage: info (files|variable|type)
subcommands:
      files - info files
      variable - info variable
      function - info funtion
(poke)

Those usage strings will probably need fixing, but I figured
I'd see what people thought of the approach first.

Signed-off-by: Oliver O'Halloran <address@hidden>
---
 src/pk-cmd.c  | 11 ++++++++++-
 src/pk-cmd.h  |  5 ++++-
 src/pk-help.c |  2 +-
 src/pk-info.c |  2 +-
 src/pk-set.c  |  2 +-
 src/pk-vm.c   |  6 +++---
 6 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/src/pk-cmd.c b/src/pk-cmd.c
index 680d5f6..31b990c 100644
--- a/src/pk-cmd.c
+++ b/src/pk-cmd.c
@@ -569,8 +569,17 @@ pk_cmd_exec_1 (char *str, struct pk_trie *cmds_trie, char 
*prefix)
   return ret;
 
  usage:
-  if (!besilent)
+  if (!besilent) {
     printf (_("Usage: %s\n"), cmd->usage);
+    if (cmd->subtrie) {
+      printf (_("subcommands:\n"));
+      for (i = 0; cmd->subcmds[i] != &null_cmd; i++)
+        {
+          printf (_("      %s - %s\n"),
+                  cmd->subcmds[i]->name, cmd->subcmds[i]->usage);
+        }
+    }
+  }
   return 0;
 }
 
diff --git a/src/pk-cmd.h b/src/pk-cmd.h
index 640e2ca..f498ce2 100644
--- a/src/pk-cmd.h
+++ b/src/pk-cmd.h
@@ -75,11 +75,14 @@ struct pk_cmd
   /* A value composed of or-ed PK_CMD_F_* flags.  See above.  */
   int flags;
   /* Subcommands.  */
-  struct pk_trie **subtrie;
+  struct pk_cmd **subcmds;
   /* Function implementing the command.  */
   pk_cmd_fn handler;
   /* Usage message.  */
   const char *usage;
+
+  /* tail element that we don't need to initialise */
+  struct pk_trie **subtrie;
 };
 
 /* Parse STR and execute a command.  */
diff --git a/src/pk-help.c b/src/pk-help.c
index 017bbc2..54d018e 100644
--- a/src/pk-help.c
+++ b/src/pk-help.c
@@ -29,4 +29,4 @@ struct pk_cmd *help_cmds[] =
 struct pk_trie *help_trie;
 
 struct pk_cmd help_cmd =
-  {"help", "", "", 0, &help_trie, NULL, "help COMMAND"};
+  {"help", "", "", 0, help_cmds, NULL, "help COMMAND", &help_trie};
diff --git a/src/pk-info.c b/src/pk-info.c
index b8e7f03..28f88b7 100644
--- a/src/pk-info.c
+++ b/src/pk-info.c
@@ -35,4 +35,4 @@ struct pk_cmd *info_cmds[] =
 struct pk_trie *info_trie;
 
 struct pk_cmd info_cmd =
-  {"info", "", "", 0, &info_trie, NULL, "info (files|variable|type)"};
+  {"info", "", "", 0, info_cmds, NULL, "info (files|variable|type)", 
&info_trie};
diff --git a/src/pk-set.c b/src/pk-set.c
index 0364763..354d1d3 100644
--- a/src/pk-set.c
+++ b/src/pk-set.c
@@ -197,4 +197,4 @@ struct pk_cmd *set_cmds[] =
 struct pk_trie *set_trie;
 
 struct pk_cmd set_cmd =
-  {"set", "", "", 0, &set_trie, NULL, "set PROPERTY"};
+  {"set", "", "", 0, set_cmds, NULL, "set PROPERTY", &set_trie};
diff --git a/src/pk-vm.c b/src/pk-vm.c
index 67569e4..b810572 100644
--- a/src/pk-vm.c
+++ b/src/pk-vm.c
@@ -201,8 +201,8 @@ struct pk_cmd *vm_disas_cmds[] =
 struct pk_trie *vm_disas_trie;
 
 struct pk_cmd vm_disas_cmd =
-  {"disassemble", "e", PK_VM_DIS_UFLAGS, 0, &vm_disas_trie, NULL,
-   "vm disassemble (expression|function)"};
+  {"disassemble", "e", PK_VM_DIS_UFLAGS, 0, vm_disas_cmds, NULL,
+   "vm disassemble (expression|function)", &vm_disas_trie};
 
 struct pk_cmd *vm_cmds[] =
   {
@@ -213,4 +213,4 @@ struct pk_cmd *vm_cmds[] =
 struct pk_trie *vm_trie;
 
 struct pk_cmd vm_cmd =
-  {"vm", "", "", 0, &vm_trie, NULL, "vm (disassemble)"};
+  {"vm", "", "", 0, vm_cmds, NULL, "vm (disassemble)", &vm_trie};
-- 
2.21.0