Patchwork [V6,09/13] monitor: support sub command in help

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Submitter Wayne Xia
Date July 11, 2013, 3:13 a.m.
Message ID <1373512429-17865-10-git-send-email-xiawenc@linux.vnet.ibm.com>
Download mbox | patch
Permalink /patch/258293/
State New
Headers show

Comments

Wayne Xia - July 11, 2013, 3:13 a.m.
The old code in help_cmd() use global 'info_cmds' and treat it as a
special case. Actually 'info_cmds' is an sub command group of 'mon_cmds',
in order to avoid direct use of it, help_cmd() need to change its work
mechanism to support sub command and not treat it as a special case
any more.

To support sub command, help_cmd() will first parse the input and then call
help_cmd_dump(), which works as an reentrant function. When it mets sub
command, it simply re-enter the function again. Since help dumping need to
know whole input to printf full help message include prefix, for example,
"help info block" need to printf prefix "info", so help_cmd_dump() takes all
args from input and extra parameter arg_index to identify the progress.
Another function help_cmd_dump_one() is introduced to printf the prefix
and command's help message.

Now help support sub command, so later if another sub command group is
added in any depth, help will automatically work for it. Still "help info
block" will show error since command parser reject additional parameter,
which can be improved later. "log" is still treated as a special case.

Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
---
 monitor.c |   63 +++++++++++++++++++++++++++++++++++++++++++++++++++---------
 1 files changed, 53 insertions(+), 10 deletions(-)

Patch

diff --git a/monitor.c b/monitor.c
index 2d4f699..c7667c3 100644
--- a/monitor.c
+++ b/monitor.c
@@ -855,33 +855,76 @@  static int parse_cmdline(const char *cmdline,
     return -1;
 }
 
+static void help_cmd_dump_one(Monitor *mon,
+                              const mon_cmd_t *cmd,
+                              char **prefix_args,
+                              int prefix_args_nb)
+{
+    int i;
+
+    for (i = 0; i < prefix_args_nb; i++) {
+        monitor_printf(mon, "%s ", prefix_args[i]);
+    }
+    monitor_printf(mon, "%s %s -- %s\n", cmd->name, cmd->params, cmd->help);
+}
+
+/* @args[@arg_index] is the valid command need to find in @cmds */
 static void help_cmd_dump(Monitor *mon, const mon_cmd_t *cmds,
-                          const char *prefix, const char *name)
+                          char **args, int nb_args, int arg_index)
 {
     const mon_cmd_t *cmd;
 
-    for(cmd = cmds; cmd->name != NULL; cmd++) {
-        if (!name || !strcmp(name, cmd->name))
-            monitor_printf(mon, "%s%s %s -- %s\n", prefix, cmd->name,
-                           cmd->params, cmd->help);
+    /* No valid arg need to compare with, dump all in *cmds */
+    if (arg_index >= nb_args) {
+        for (cmd = cmds; cmd->name != NULL; cmd++) {
+            help_cmd_dump_one(mon, cmd, args, arg_index);
+        }
+        return;
+    }
+
+    /* Find one entry to dump */
+    for (cmd = cmds; cmd->name != NULL; cmd++) {
+        if (compare_cmd(args[arg_index], cmd->name)) {
+            if (cmd->sub_table) {
+                /* continue with next arg */
+                help_cmd_dump(mon, cmd->sub_table,
+                              args, nb_args, arg_index + 1);
+            } else {
+                help_cmd_dump_one(mon, cmd, args, arg_index);
+            }
+            break;
+        }
     }
 }
 
 static void help_cmd(Monitor *mon, const char *name)
 {
-    if (name && !strcmp(name, "info")) {
-        help_cmd_dump(mon, info_cmds, "info ", NULL);
-    } else {
-        help_cmd_dump(mon, mon->cmd_table, "", name);
-        if (name && !strcmp(name, "log")) {
+    char *args[MAX_ARGS];
+    int nb_args = 0;
+
+    /* 1. parse user input */
+    if (name) {
+        /* special case for log, directly dump and return */
+        if (!strcmp(name, "log")) {
             const QEMULogItem *item;
             monitor_printf(mon, "Log items (comma separated):\n");
             monitor_printf(mon, "%-10s %s\n", "none", "remove all logs");
             for (item = qemu_log_items; item->mask != 0; item++) {
                 monitor_printf(mon, "%-10s %s\n", item->name, item->help);
             }
+            return;
+        }
+
+        if (parse_cmdline(name, &nb_args, args) < 0) {
+            goto cleanup;
         }
     }
+
+    /* 2. dump the contents according to parsed args */
+    help_cmd_dump(mon, mon->cmd_table, args, nb_args, 0);
+
+cleanup:
+    free_cmdline_args(args, nb_args);
 }
 
 static void do_help_cmd(Monitor *mon, const QDict *qdict)