bkp - toggle ".bkp" extension

bkp.bash

#! /usr/bin/env bash

# All my gist code is licensed under the MIT license.

# Add this somewhere in your .bashrc

# bkp
# - toggle a ".bkp" extension to a file(s)
function bkp () {
  # print usage on -h/--help or no arguments
  if [[ "$#" -eq 1 && ("$1" == "-h" || "$1" == "--help") ]]; then
    echo "${bold}Usage:${reset} bkp <file>..."
    echo "  - If the file has a '.bkp' extension, remove it"
    echo "  - If the file does not have a '.bkp' extension, add it"
    echo "  - Do nothing if a file with the new name already exists"
    return 1
  fi

  # first, create array of all the final files
  local newFiles=()
  for file in "$@"; do
    if [[ "$file" == *.bkp ]]; then
      newFiles+=("${file%.bkp}")
    else
      newFiles+=("${file}.bkp")
    fi
  done

  # bail out if any of the new files already exists
  for file in "${newFiles[@]}"; do
    if [[ -f "$file" ]]; then
      echo "${red}Error:${reset} This script would overwrite ${bold}$file${reset}. Bailing out."
      return 1
    fi
  done

  # rename files
  local index=0
  for file in "$@"; do
    mv "$file" "${newFiles[$index]}"
    index=$((index + 1))
  done
}