urlencode.sh

#!/bin/sh

urlencode() {
  c="${1%${1#?}}"
  if [ -n "$c" ]; then
    case "$c" in
      [a-zA-Z0-9.~_-]) printf "$c" ;;
      *) printf '%%%.2X' "'$c" ;;
    esac
    urlencode "${1#?}"
  fi
}