Get all lines containing a string in a huge text file - as fast as possible?

Question

In Powershell, how to read and get as fast as possible the last line (or all the lines) which contains a specific string in a huge text file (about 200000 lines / 30 MBytes) ?

Answer 1

Have you tried:

gc myfile.txt | % { if($_ -match "my_string") {write-host $_}}

Or, you can create a "grep"-like function:

function grep($f,$s) {
    gc $f | % {if($_ -match $s){write-host $_}}
    }

Then you can just issue: grep $myfile.txt $my_string