Making Linux commands shorter

Here are a few ways to shorten your Linux/UNIX/*BSD commands. Keep in mind that some short commands are less readable by others.

Long version Short version Characters won Application
cd $HOME cd 6 Shell
cat file | grep -v some | grep -v thing grep -vE 'some|thing' file 13 Shell
sort file | uniq sort -u file 4 Shell
:wq! :x 2 vi
boot bsd bsd 5 OpenBSD bootloader
grep -v '^#' file | grep -v '^$' grep -vE '^#|^$' file 11 Shell