Reimplementing grep One of’s challenges is to reimplement grep in bash. Here’s a walk through of how I solved it. Solution 1 #/bin/env bash grep "${@}" exit 0 This solution probably isn’t in the spirit of the challenge, but it does satisfy all the tests. Time to go home. Solution 2 For the same reasons why you shouldn’t use a word in its own definition, reimplementations shouldn’t use the original tool.