Have you noticed that most terminal commands are at least two letters long?
This is certainly the case for built in unix commands:
Two letter examples: ls, cd, cp, mv, rm.
Three letter examples: pwd, cat, kill, awk, cut.
Longer examples: alias, chmod, chown, crontab, time, xargs.
There is no single letter command to be found among the built in ones. But what if we widen our search to non built in ones?
node, python, git, wget, yarn, go, postgresql, cmake, imagemagick, openssl, mysql, vim, ffmpeg
No single letters found there either.
This means you are in luck! The single letters are yours to define. You may give your bash aliases single letter names.
That’s 26 free commands (qwertyuiopasdfghjklzxcvbnm) that can be typed really quickly because they are as short as it gets.