---
name: "xymond_channel"
section: "8"
platform: "linux"
package: "xymon"
version: "4.3.30-4"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/xymond_channel"
---

# xymond\_channel(8)

Feed a xymond channel to a worker module

## NAME

xymond\_channel - Feed a xymond channel to a worker module

## SYNOPSIS

**xymond\_channel --channel=CHANNEL \[options\] workerprogram \[worker-options\]**

## DESCRIPTION

xymond\_channel hooks into one of the  *[xymond(8)](/xymond/8.md)* channels that provide information about events occurring in the Xymon system. It retrieves messages from the xymond daemon, and passes them on to the **workerprogram** on the STDIN (file descripter 1) of the worker program.  Worker programs can then handle messages as they like.

A number of worker programs are shipped with xymond, e.g. *[xymond\_filestore(8)](/xymond_filestore/8.md)* *[xymond\_history(8)](/xymond_history/8.md)* *[xymond\_alert(8)](/xymond_alert/8.md)* *[xymond\_rrd(8)](/xymond_rrd/8.md)*

If you want to write your own worker module, a sample worker module is provided as part of the xymond distribution in the xymond\_sample.c file. This illustrates how to easily fetch and parse messages.

## OPTIONS

xymond\_channel accepts a few options.

- \--channel=CHANNELNAME

  Specifies the channel to receive messages from, only one channel can be used. This option is required. The following channels are available:\
   "status" receives all Xymon status- and summary-messages\
   "stachg" receives information about status changes\
   "page" receives information about statuses triggering alerts\
   "data" receives all Xymon "data" messages\
   "notes" receives all Xymon "notes" messages\
   "enadis" receives information about hosts being disabled or enabled.

- \--filter=EXPRESSION

  EXPRESSION is a Perl-compatible regular expression. xymond\_channel will match  the first line of each message against this expression, and silently drops any message that does not match the expression. Especially useful for custom  worker modules and during testing, to limit the amount of data that the module must process.\
   Note that messages for "logrotate", "shutdown", "drophost", "renamehost", "droptest" and "renametest" are always forwarded by xymond\_channel, whether they match the filter or not.

- \--msgtimeout=TIMEOUT

  Modify the default timeout (30 seconds) for the worker module to handle a message. If a message is not handled within this time, it is considered lost. You normally do not have to modify this unless you have an extremely busy server.

- \--daemon

  xymond\_channel is normally started by  *[xymonlaunch(8)](/xymonlaunch/8.md)* as a task defined in the *[tasks.cfg(5)](/tasks.cfg/5.md)* file. If you are not using xymonlaunch, then starting xymond\_channel with this option causes it to run as a stand-alone background task.

- \--pidfile=FILENAME

  If running as a stand-alone daemon, xymond\_channel will save the process-ID  of the daemon in FILENAME. This is useful for automated startup- and shutdown- scripts.

- \--env=FILENAME

  Loads the environment variables defined in FILENAME before starting xymond\_channel. This is normally used only when running as a stand-alone daemon; if xymond\_channel is started by xymonlaunch, then the environment is controlled by the task definition  in the *[tasks.cfg(5)](/tasks.cfg/5.md)* file.

- \--log=FILENAME

  Redirect output to this log-file.

- \--md5 / --no-md5

  Enable/disable checksumming of messages passed from xymond\_channel to the worker module. This may be useful if you suspect that data may be corrupted, e.g. when sent to a remote worker module. Note that enabling this may break communication with old versions of Xymon worker modules. Default: Disabled.

- \--debug

  Enable debugging output.

## FILES

This program does not use any configuration files.

## SEE ALSO

[xymond(8)](/xymond/8.md), [xymon(7)](/xymon/7.md)