[SOLVED] bash 'echo' displaying NULL result

TashiDuks · 12-07-2016, 11:51 PM

I have configuration file named "mymy.conf" with following content

Code:

 "subject" : "My HTTP alert on $device.node_id"

The following script should display the value of "subject" but it displays nothing/null.

Code:

#! /bin/bash
curSubj=`grep -oP '"subject" : "\K.*(?=\$device.node_id)' .mymy.conf`
echo "$curSubj"

When i run the same syntax in terminal i.e.grep -oP '"subject" : "\K.*(?=\$device.node_id)' it displays the result as My HTTP alert on but when i run the script it does not display the result.

Is there any difference? Help Please.

Thanks

pan64 · 12-08-2016, 12:54 AM

use \\ instead of \, ` will add an additional evaluation step

TashiDuks · 12-08-2016, 01:02 AM

Thanks @pan64 for your response. It worked!!!

Cheers

MadeInGermany · 12-08-2016, 11:31 AM

Or try $(...) instead of `...`
Normally it does not need extra escapes.