Perl

Perl is everywhere. I really need to learn perl.

Perl Interpreter

Perl doesn't use an interpreter quite like python, but there is a debug prompt which lets you use it that way:

perl -de 1								#start interpreter

DB<1> print "hello world"			#example print command
hello world
DB<2>

Multiline Search/Replace

# Replace `Gradient "Nose"` and the 2x lines following it
# with `Gradient "Head"
perl -0777 -pe 's/Gradient "Nose".*\n.*\n.*/Gradient "Head"/g' myfile.txt