[PATCH] nscd: list all tables in usage()

[Sami Kerola <kerolasa at iki dot fi>]

On 1 January 2014 17:27, Mike Frysinger <vapier@gentoo.org> wrote:
> On Wednesday 01 January 2014 07:38:35 Sami Kerola wrote:
>> Usage output for option --invalidate=TABLE is not helpful without
>> list of tables.  The list is also missing from nscd(8) manual which
>> made it pretty difficult to know what are the tables.
>
> can you show an example of before & after output ?

Hi Mike,

Here comes the new output. It has 'TABLE list: ...' line, and does not
differ any other way in-comparison with the old so I don't think there is
need to have the other output a side.

-- snip
$ ./nscd/nscd --help
Usage: nscd [OPTION...]
Name Service Cache Daemon.

  -d, --debug                Do not fork and display messages on the current
                             tty
  -f, --config-file=NAME     Read configuration data from NAME
  -F, --foreground           Do not fork, but otherwise behave like a daemon
  -g, --statistics           Print current configuration statistics
  -i, --invalidate=TABLE     Invalidate the specified cache
  -K, --shutdown             Shut the server down
  -t, --nthreads=NUMBER      Start NUMBER threads
  -?, --help                 Give this help list
      --usage                Give a short usage message
  -V, --version              Print program version

Mandatory or optional arguments to long options are also mandatory or optional
for any corresponding short options.

TABLE list: passwd group hosts services netgroup

For bug reporting instructions, please see:
<http://www.gnu.org/software/libc/bugs.html>.
-- snip

>> --- a/nscd/nscd.c
>> +++ b/nscd/nscd.c
>>  more_help (int key, const char *text, void *input)
>>  {
>> -  char *tp = NULL;
>> +  char *tables, *p, *tp = NULL;
>>    switch (key)
>>      {
>>      case ARGP_KEY_HELP_EXTRA:
>> +      {
>> +     dbtype cnt;
>> +     size_t len;
>> +     tables = xmalloc (sizeof (dbnames) + 1);
>
> i think GNU style says there should be a newline after the decls

Oh, good that you said.  I had no idea about such convention.

>> +     p = tables;
>> +     for (cnt = 0; cnt < lastdb; cnt++)
>> +       {
>> +         len = strlen (dbnames[cnt]);
>> +         memcpy (p, dbnames[cnt], len);
>> +         p += len;
>> +         *p++ = ' ';
>
> how about just strcat ?  would be a little slower, but would be simpler
> code.
>         tables = xmalloc (sizeof (dbnames) + 1);
>         for (cnt = 0; cnt < lastdb; ++cnt) {
>                 strcat (tables, dbnames[cnt]);
>                 strcat (tables, ' ');
>         }

Performance of usage() output surely cannot be critical.  If the strcat()
is seen as easier to read I don't mind writing the change using it.  See
the.  Here is the second edition.


 
--->8----
From: Sami Kerola <kerolasa@iki.fi>
Date: Wed, 1 Jan 2014 20:17:20 +0000
Subject: [PATCH] nscd: list all tables in usage()

Usage output for option --invalidate=TABLE is not helpful without
list of tables.  The list is also missing from nscd(8) manual which
made it pretty difficult to know what are the tables.
---
 ChangeLog   |  4 ++++
 nscd/nscd.c | 20 +++++++++++++++++---
 2 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index c2c47d8..a9c7ddb 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2014-01-01  Sami Kerola  <kerolasa@iki.fi>
+
+	* nscd/nscd.c: Improve usage() output.
+
 2014-01-01  Allan McRae  <allan@archlinux.org>
 
 	* scripts/update-copyrights: Update configure input file suffix.
diff --git a/nscd/nscd.c b/nscd/nscd.c
index e7f04f8..755c060 100644
--- a/nscd/nscd.c
+++ b/nscd/nscd.c
@@ -442,15 +442,29 @@ parse_opt (int key, char *arg, struct argp_state *state)
 static char *
 more_help (int key, const char *text, void *input)
 {
-  char *tp = NULL;
+  char *tables, *tp = NULL;
   switch (key)
     {
     case ARGP_KEY_HELP_EXTRA:
+      {
+	dbtype cnt;
+
+	tables = xcalloc (1, sizeof (dbnames) + 1);
+	for (cnt = 0; cnt < lastdb; cnt++)
+	  {
+            strcat (tables, dbnames[cnt]);
+	    strcat (tables, " ");
+	  }
+      }
+
       /* We print some extra information.  */
       if (asprintf (&tp, gettext ("\
+TABLE names are: %s\n\
+\n\
 For bug reporting instructions, please see:\n\
-%s.\n"), REPORT_BUGS_TO) < 0)
-	return NULL;
+%s.\n"), tables, REPORT_BUGS_TO) < 0)
+	tp = NULL;
+      free(tables);
       return tp;
     default:
       break;
-- 
1.8.5.2