Vim

Opening Multiple Files at once in split mode

:argedit file1.txt file2.txt | all

Extracting IP Addresses

:g/\(\d\{1,3}\.\)\{3}\d\{1,3\}/y A

Count the Number of Words in a File

A simple vim one liner which allows you to count the words in the file as this can be very handy.

:%s/\w\+/\=submatch(0)+1/g | echo line('$')