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

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
<user-71895fb2e44c@xymon.invalid>
wrote:

On 17 October 2014 15:16, Tracy Di Marco White <user-4d3c8321d54f@xymon.invalid>
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