Perl is a computer language often used for scripting purposes. While the name is said to stand for "Practical Extraction and Report Language", it isn't actually an acronym. (Larry Wall, the creator, calls it "Pathologically Eclectic Rubbish Lister".)

It's known for the terseness with with you can express operations, a feature which has earned it the moniker of a write-only language.

For example, to scan through a file and make a global change, it can be expressed as tersely as :

open INFILE, "input.txt";
open OUTFILE, ">output.txt";
while (<INFILE>) {	
	s/Old text/New text/;
	print OUTFILE ;