[Xymon] function run_command in ../lib/run.c assumes sh but uses any $SHELL

[Tracy Di Marco White]

Since I've been running bb/hobbit/xymon a very long time, upgrades don't
touch my config files, I tend to go through them by hand. That one is the
one line I missed, it looks like.

-Tracy

On Fri, Oct 17, 2014 at 11:24 AM, J.C. Cleaver <cleaver at terabithia.org>
wrote:

>
> This is correct; there was change to do exactly this to allow alternative
> shells to be used directly (or not fork a shell at all if it wasn't
> needed).
>
> There *should* be a SHELL= line in xymonserver.cfg and xymonclient.cfg
> which is where this would be set -- by default to /bin/sh -- which would
> take effect for xymonlaunch-executed commands and their children
> (including ntpdate).
>
> Is there an .rpmnew or .pkg file that didn't get applied perhaps? How did
> the upgrade occur?
>
>
> Regards,
>
> -jc
>
>
>
> On Fri, October 17, 2014 8:56 am, Tracy Di Marco White wrote:
> > I'm using xymon 4.3.17, and server is what does the ntpdate test. Here's
> > the snippet of code in question:
> >                 if (strchr(cmd, ' ') == NULL) execlp(cmd, cmd, NULL);
> >                 else {
> >                         char *shell = getenv("SHELL");
> >                         if (!shell) shell = "/bin/sh";
> >                         execl(shell, "sh", "-c", cmd, NULL);
> >                 }
> >                 exit(127);
> >
> > Note that 4.3.10 does what you say. I have that in the clients I have.
> >
> > If I restart it as me, ntpdate is run, but not with an sh derivative. My
> > shell is tcsh, and what I start uses my environment variables. My init
> > script also has #!/bin/sh as the first line, but that doesn't necessarily
> > prevent environment variables from being inherited.
> > # echo $tcsh
> > 6.18.01
> > # sh
> > # echo $SHELL
> > /bin/tcsh
> > I've added setting the shell to my startup script for now. And, to show
> > you
> > what's happening, here's a snippet that echoes $SHELL:
> > xymon_precmd()
> > {
> >         echo $SHELL
> >         SHELL="/bin/sh"
> >         export SHELL
> >
> >         touch ${xymon_pidfile} && chown ${xymon_user} ${xymon_pidfile}
> > }
> >
> > And so, even though the startup script is run with /bin/sh, the $SHELL
> > variable is still set to /bin/tcsh:
> > # /etc/rc.d/xymon restart
> > Stopping xymon.
> > Waiting for PIDS: 29042.
> > /bin/tcsh
> > Starting xymon.
> > #
> >
> > -Tracy
> >
> >
> > On Thu, Oct 16, 2014 at 11:43 PM, Jeremy Laidman
> > <jlaidman at rebel-it.com.au>
> > wrote:
> >
> >> On 17 October 2014 15:16, Tracy Di Marco White <gendalia at iastate.edu>
> >> wrote:
> >>
> >>> If I restart xymon while using tcsh, for example, suddenly my ntp test
> >>> breaks,
> >>>
> >>
> >> Is this a client or server?  How did you restart xymon?  My init script
> >> has "#! /bin/sh" in the first line, so I don't think it should matter
> >> what
> >> shell I run it from.
> >>
> >>
> >>> For the moment, I've hard coded 'export SHELL=/bin/sh' in the startup
> >>> script for xymon, but the assumption shouldn't be made that $SHELL is a
> >>> /bin/sh derivative.
> >>>
> >>
> >> Curiously, the code that runs the "ntpdate" command is this:
> >>
> >>   execl("/bin/sh", "sh", "-c", cmd, NULL);
> >>
> >> where "cmd" is the command (passed into the run_command() function.  So,
> >> I'm perplexed why it should matter what shell is running.  As far as I
> >> can
> >> tell, none of Xymon's binaries or scripts reference $SHELL.
> >>
> >> Cheers
> >> Jeremy
> >>
> >>
> > _______________________________________________
> > Xymon mailing list
> > Xymon at xymon.com
> > http://lists.xymon.com/mailman/listinfo/xymon
> >
>
>
>
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