In response to the current /. poll, Most Useful UNIX Tool: I have the following from my ~/.zhistory at work:

Which is interesting to me. I can explain some of the counts:

• I run cat $file | (grep|sed|awk) | ... too often out of a good/bad habit.
• exit is small because I’ve bound x to exit (which itself is a bad habit; I should have just started using Control-D.
• ssh > telnet
• I don’t have root, so init isn’t really used, and my regex isn’t careful enough to eliminate disk_init.
• sed is mega-useful, but is usually the second command in a pipeline. I want to start using perl -pe more.