Shell features you didn't know you needed (or...

I came across this one needing to turn a Git branch name into a Docker image tag, and having it trip over the fact that our branch naming convention is <user>/<issue>/<short description>, and Docker doesn't like / in tags. Obviously there are many ways of stripping/substituting the /: for example, using tr IMAGE_TAG=$(echo $BRANCH | tr \/ \-) using sed IMAGE_TAG=$(echo $BRANCH | sed -e 's/\//-/g') using perl IMAGE_TAG=$(echo $BRANCH | perl -pe 's/\//-/g') And there's probably others with awk, an