[PATCH] wall: Print time and date (rather than just time) in wall banner

[PATCH] wall: Print time and date (rather than just time) in wall banner

[Dave Rutherford]

Hello,

This is a simple change to print the date and time in the wall banner.
Previously just the time was printed.  This made more sense during the era
of scarce and/or real terminals with interactive sessions of brief usage,
when a terminal was likely to be attended, but makes less sense in the era
of long-lived x-terminals, screen sessions, and so forth.  The latter may
be left open for days or weeks at a time, and returning to one it may no
longer be obvious just when a wall message was sent.  This can be relevant.

This adds the seconds and the date (locale-appropriate format) to the
wall banner, if any.

Regards,
   Dave Rutherford <dave@evilpettingzoo.com>


$ diff -u term-utils/wall.c.orig term-utils/wall.c
--- term-utils/wall.c.orig      2015-06-25 04:31:10.957160529 -0400
+++ term-utils/wall.c   2015-06-26 01:45:04.150729302 -0400
@@ -238,8 +238,9 @@
                sprintf(lbuf, _("Broadcast Message from %s@%s"),
                              whom, hostname);
                fprintf(fp, "%-79.79s\007\007\r\n", lbuf);
-               sprintf(lbuf, "        (%s) at %d:%02d ...",
-                             where, lt->tm_hour, lt->tm_min);
+               cnt = sprintf(lbuf, "        (%s) at ", where);
+               mbuf = lbuf + cnt;
+               strftime(mbuf, 79-cnt, "%T %x ...", lt);
                fprintf(fp, "%-79.79s\r\n", lbuf);
        }
        fprintf(fp, "%79s\r\n", " ");

Re: [PATCH] wall: Print time and date (rather than just time) in wall banner

[Sami Kerola]

On 27 June 2015 at 01:34, Dave Rutherford <dave@evilpettingzoo.com> wrote:
> This is a simple change to print the date and time in the wall banner.
> Previously just the time was printed.  This made more sense during the era
> of scarce and/or real terminals with interactive sessions of brief usage,
> when a terminal was likely to be attended, but makes less sense in the era
> of long-lived x-terminals, screen sessions, and so forth.  The latter may
> be left open for days or weeks at a time, and returning to one it may no
> longer be obvious just when a wall message was sent.  This can be relevant.
>
> This adds the seconds and the date (locale-appropriate format) to the
> wall banner, if any.
>
> Regards,
>    Dave Rutherford <dave@evilpettingzoo.com>
>
>
> $ diff -u term-utils/wall.c.orig term-utils/wall.c
> --- term-utils/wall.c.orig      2015-06-25 04:31:10.957160529 -0400
> +++ term-utils/wall.c   2015-06-26 01:45:04.150729302 -0400
> @@ -238,8 +238,9 @@
>                 sprintf(lbuf, _("Broadcast Message from %s@%s"),
>                               whom, hostname);
>                 fprintf(fp, "%-79.79s\007\007\r\n", lbuf);
> -               sprintf(lbuf, "        (%s) at %d:%02d ...",
> -                             where, lt->tm_hour, lt->tm_min);
> +               cnt = sprintf(lbuf, "        (%s) at ", where);
> +               mbuf = lbuf + cnt;
> +               strftime(mbuf, 79-cnt, "%T %x ...", lt);
>                 fprintf(fp, "%-79.79s\r\n", lbuf);
>         }
>         fprintf(fp, "%79s\r\n", " ");

Hi Dave,

It seems your patch is wrote using rather old util-linux source.  The
code segment in question has got at least one change[1], that makes
banner to be sysvinit compatible.  Banner now uses a date string similar
to date(1) default output, and it tends get truncated[2].  While back I
thought splitting the banner to multiple lines might be good idea, but
the wat I proposed the change did not satisfy review process[3].

Problem seems to be that the current header format simply does not have
enough room for all the information, and no-one has come up with a good
idea what would be better alternative format.  Maybe the later has not
been thought too much, and most certainly there has not been proposals
for alternative(s).

That said now when everything is turning to json, maybe header and
message should be json as well.  Something like:

{
  "title": "Broadcast message"
  "from": "foobar@example.com"
  "tty": "pts/2"
  "date": "2015-06-27T09:18:36+0100"
  "message": "the stuff users write"
}

[1] https://github.com/karelzak/util-linux/commit/d81c30553f4fb49173d38f69edff4b0b67a18b65
[2] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=682778
[3] http://marc.info/?l=util-linux-ng&m=140661986032132&w=2

-- 
Sami Kerola
http://www.iki.fi/kerolasa/

Re: [PATCH] wall: Print time and date (rather than just time) in wall banner

[Karel Zak]

On Sat, Jun 27, 2015 at 09:20:58AM +0100, Sami Kerola wrote:
> That said now when everything is turning to json, maybe header and
> message should be json as well.  Something like:

 For humans? Why?

> {
>   "title": "Broadcast message"
>   "from": "foobar@example.com"
>   "tty": "pts/2"
>   "date": "2015-06-27T09:18:36+0100"
>   "message": "the stuff users write"
> }

Anyway, I don't think the current output is so bad that we have to
change it.

    Karel

-- 
 Karel Zak  <kzak@redhat.com>
 http://karelzak.blogspot.com