introduce nscd --foreground, for systemd use

[Alexandre Oliva]

On Jan 23, 2012, Roland McGrath <roland@hack.frob.com> wrote:

> This seems generally sound to me.  But I'd like to know if there is
> any existing precedent for an option letter and/or long option name
> for doing this in another GNU utility.

I'm afraid I couldn't find examples of programs that offered this level
of flexibility, so I saught guidance in the GNU coding standards.
http://www.gnu.org/prep/standards/standards.html#Option-Table

‘foreground’
    For server programs, run in the foreground; in other words, don’t do
    anything special to run the server in the background.

‘debug’
    ‘-d’ in make and m4; ‘-t’ in Bison.

There doesn't seem to be a standard short option for “--foreground”;
indeed, some non-GNU programs use -d to daemonize, whereas others use it
to enter debugging mode.  I couldn't tell (by just looking at remote
docs) whether they changed behavior WRT syslog when they offered both
options.  It's a bit of a mess already :-(

> Perhaps cleaner to have two bools.

I've considered adding --[no-]syslog, but we don't really have 4
different possibilities in the choice space.  It doesn't make sense to
send output to std* if you daemonize: it's really 3-state.

Or (4-, 5- or) 6-state, if we were to add “paranoid mode” as a
(non-)orthogonal dimension in the choice space.

>> +	fprintf (stderr, _("further output sent to syslog\n"));

> What's the point of this message?

It's just so that someone who runs the program in --foreground isn't
surprised by the absence of output when the program runs in foreground,
behavior that is new and unlike that of -d.

> It's not normal for daemon startup to print anything to stderr in my
> experience.

This won't be printed in daemon mode, only in --foreground mode.

-- 
Alexandre Oliva, freedom fighter    http://FSFLA.org/~lxoliva/
You must be the change you wish to see in the world. -- Gandhi
Be Free! -- http://FSFLA.org/   FSF Latin America board member
Free Software Evangelist      Red Hat Brazil Compiler Engineer