src/rrd_daemon.c: Implemented the `HELP' command.

diff --git a/src/rrd_daemon.c b/src/rrd_daemon.c
index 7e46dca..7a51f5d 100644 (file)
--- a/src/rrd_daemon.c
+++ b/src/rrd_daemon.c
@@ -601,6 +601,104 @@ static int flush_file (const char *filename) /* {{{ */
   return (0);
 } /* }}} int flush_file */
 
+static int handle_request_help (int fd, /* {{{ */
+    char *buffer, size_t buffer_size)
+{
+  int status;
+  char **help_text;
+  size_t help_text_len;
+  char *command;
+  size_t i;
+
+  char *help_help[] =
+  {
+    "4 Command overview\n",
+    "FLUSH <filename>\n",
+    "HELP [<command>]\n",
+    "UPDATE <filename> <values> [<values> ...]\n",
+    "STATS\n"
+  };
+  size_t help_help_len = sizeof (help_help) / sizeof (help_help[0]);
+
+  char *help_flush[] =
+  {
+    "4 Help for FLUSH\n",
+    "Usage: FLUSH <filename>\n",
+    "\n",
+    "Adds the given filename to the head of the update queue and returns\n",
+    "after is has been dequeued.\n"
+  };
+  size_t help_flush_len = sizeof (help_flush) / sizeof (help_flush[0]);
+
+  char *help_update[] =
+  {
+    "9 Help for UPDATE\n",
+    "Usage: UPDATE <filename> <values> [<values> ...]\n"
+    "\n",
+    "Adds the given file to the internal cache if it is not yet known and\n",
+    "appends the given value(s) to the entry. See the rrdcached(1) manpage\n",
+    "for details.\n",
+    "\n",
+    "Each <values> has the following form:\n",
+    "  <values> = <time>:<value>[:<value>[...]]\n",
+    "See the rrdupdate(1) manpage for details.\n"
+  };
+  size_t help_update_len = sizeof (help_update) / sizeof (help_update[0]);
+
+  char *help_stats[] =
+  {
+    "4 Help for STATS\n",
+    "Usage: STATS\n",
+    "\n",
+    "Returns some performance counters, see the rrdcached(1) manpage for\n",
+    "a description of the values.\n"
+  };
+  size_t help_stats_len = sizeof (help_stats) / sizeof (help_stats[0]);
+
+  status = buffer_get_field (&buffer, &buffer_size, &command);
+  if (status != 0)
+  {
+    help_text = help_help;
+    help_text_len = help_help_len;
+  }
+  else
+  {
+    if (strcasecmp (command, "update") == 0)
+    {
+      help_text = help_update;
+      help_text_len = help_update_len;
+    }
+    else if (strcasecmp (command, "flush") == 0)
+    {
+      help_text = help_flush;
+      help_text_len = help_flush_len;
+    }
+    else if (strcasecmp (command, "stats") == 0)
+    {
+      help_text = help_stats;
+      help_text_len = help_stats_len;
+    }
+    else
+    {
+      help_text = help_help;
+      help_text_len = help_help_len;
+    }
+  }
+
+  for (i = 0; i < help_text_len; i++)
+  {
+    status = write (fd, help_text[i], strlen (help_text[i]));
+    if (status < 0)
+    {
+      status = errno;
+      RRDD_LOG (LOG_ERR, "handle_request_help: write(2) returned an error.");
+      return (status);
+    }
+  }
+
+  return (0);
+} /* }}} int handle_request_help */
+
 static int handle_request_stats (int fd, /* {{{ */
     char *buffer __attribute__((unused)),
     size_t buffer_size __attribute__((unused)))
@@ -870,6 +968,10 @@ static int handle_request (int fd) /* {{{ */
   {
     return (handle_request_stats (fd, buffer_ptr, buffer_size));
   }
+  else if (strcasecmp (command, "help") == 0)
+  {
+    return (handle_request_help (fd, buffer_ptr, buffer_size));
+  }
   else
   {
     char result[4096];