Feature: string search with `.grepLinesGzip()`

[nvnieuwk]

Hi,

Is it possible to add a feature where you use a string value as input to .grepLinesGzip() to make it work like the bash command zgrep? This will be very powerful to dynamically filter lines from the output files without having to look up the exact line numbers of the lines you would want to test for.

Thanks in advance

-Nicolas