Vim for hackers
Run a OS command on each line in the file
:%!COMMAND
:%!sort # sort all the lines alphabetically
:%!sort | uniq #remove duplicate lines
:%!tac #reverse lines (last line to first line)
:%!base64 -d #base64 decode one line at a time
Extract IP addresses in a file
:%!grep -oE '([0-9]{1,3}\.){3}[0-9]{1,3}'