zet

Shell printf is Not Same as Other Languages

If you are coming to shell programming (bash, POSIX, whatever) from another language that has a printf function you likely will not expect the way the shell version behaves. Most notably, it will repeated print the filled in template string for each argument that follows it. Other languages would give you some kind of error about the number or type or arguments on syncing up.

This actually allows some pretty creative idioms. For example, you can use this to join the incoming arguments to a function:

#!/usr/bin/bash

commands=(foo bar help usage)

join() {
  delim="$1"
  first="$2"
  shift 2
  printf "%s" "$first" "${@/#/$delim}"
}

join '|' commands

This site is open source. Improve this page.