[TBurette]

Make it check for errors by default instead of blindly keeping running (set -euo by default).

Have a way to undelete files (undelete or a trash folder).

Not being so whitespace sensitive. One of those two commands does what you think it does, the other not : grep --exclude-dir= ".git" -rl 123 . grep --exclude-dir=".git" -rl 123 .

Make it easier to iterate through file of a directory no matter what the filenames may contain(dashes, spaces,...)

Be more consistant between different commands.

  adduser vs newgrp
  -o vs + (Or-ing elements)

Use a modern regexp. For example with grep x* works but x? doesn't (you must use x\? or a flag)

Write man pages so that they are useful in the 'I have an idea what this command does and want to learn it' scenario, not just 'I know this command and need a quick refresher on a specific flag'.

[gregjor]

I think you’re mixing up the shell program (sh, bash, csh, zsh, etc.) with the Unix/Linux environment. The names of commands (adduser, newgrp) have nothing to do with the shell. Undeleting would get implemented in the file system (multiple solutions to that exist already). grep is a separate executable (with many variants and alternatives), not part of the shell. Man pages are not part of the shell either.