[SOLVED] Return results for Ubuntu Updates in a Variable

Issue

I am trying to get the result from /usr/lib/update-notifier/apt-check on a Ubuntu 16 Server into a Array to make a XML response for a monitoring tool, but somehow the value of this apt-check just refuses to get in my Variable. For simplicity sake, I have omitted the XML creation part.

#!/bin/bash
APTCHECK="/usr/lib/update-notifier/apt-check"
APTResult="$(${APTCHECK})"
echo "Result is $APTResult"
exit 0

if you now run this code with bash -x you will see that the result is returned to the Terminal, but not assigned to the Variable. If I substitute the "command" to something simple like "ls -lah" everything works fine.

I just don't know why this is not working ? Anybody ?

Solution

apt-check prints to the stderr, so you need to capture that instead with aptresult=$(/usr/lib/update-notifier/apt-check 2>&1).

The other option is with the --human-readable switch, which'll print to the stdout. The only problem then is that you have to parse the text output (unless the text output is what you actually want).

Answered By - Olli K