bash - shell script : replace contents -

i have file following info

filename:versioninfo.properties

installed version:13.7.0-2 previous version:13.6.0-12 

filename: rollback.sh

#!/bin/bash uninstall_rpm clientinfrastructure $version 

how can value variable $version previous version of versioninfo.properties file. $version should have value 13.6.0-12

sed solution:

version=$(sed -n 's/previous version:\(.*\)/\1/p' versioninfo.properties) 

to use in script can do:

#!/bin/bash version=$(sed -n 's/previous version:\(.*\)/\1/p' versioninfo.properties) uninstall_rpm clientinfrastructure "$version" 

if have in script can on command line.

uninstall_rpm clientinfrastructure "$(sed -n 's/previous version:\(.*\)/\1/p' versioninfo.properties)"