Code for parsing a key/value in in file from shell script

Question

I have a file that I need to look up a value by key using a shell script. The file looks like:

HereIsAKey This is the value

How can I do something like:

MyVar=Get HereIsAKey

and then MyVar should equal "This is the value". The key has no whitespace and the value should be everything following whitespace after the key.

Answer 1

if HereIsAKey is unique in your file, try this with grep:

myVar=$(grep -Po "(?<=^HereIsAKey ).*" file)

Answer 2

If you don't have a grep that supports Perl-compatible regular expressions, the following seems to work:

VAR=$(grep "^$KEY " file | cut -d' ' -f2-)