In college during the introduction to command-line class the professor simply required everyone to write only POSIX-compliant shell scripts. And your shell scri

In college during the introduction to command-line class the professor simply required everyone to write only POSIX-compliant shell scripts. And your shell scripts must work with newlines in file names. We did fun things like parsing (a subset of) HTML using only sed (did you know about sed's hold space and pattern space?). It was basically an intellectual puzzle for geeks with too much time on hand.