Run GNU programs installed as Keg-only Brew packages: `gnu <command> [<args ...>]`.

run_keg_only_gnu_program.sh

# Runs an executable in a Keg-only Brew package that's not in PATH.
# Finds an executable named `$1` or `g$1` in formula `$1`, `g$1`, `coreutils`, or `findutils`.
# Note: Always searches in that order. This is significant for commands starting with `g`.
# Usage: gnu <command> [<args ...>]
gnu() {
  if (( $# == 0 )); then
    printf >&2 "\e[0;1;31mUsage: %s <command> [args...]\e[0m\n" "${FUNCNAME[0]}"
    return 2
  fi
  if ! command -v brew > /dev/null 2> /dev/null; then
    printf >&2 "\e[0;1;31mBrew is not installed.\e[0m\n"
    return 127
  fi
  local _opt="$HOMEBREW_PREFIX"/opt
  _paths=(
    "$_opt/$1/bin/$1"
    "$_opt/$1/bin/g$1"
    "$_opt/g$1/bin/g$1"
    "$_opt/coreutils/bin/$1"
    "$_opt/coreutils/bin/g$1"
    "$_opt/findutils/bin/$1"
    "$_opt/findutils/bin/g$1"
  )
  local _path
  for _path in "${_paths[@]}"; do
    if [[ -e "$_path" ]]; then
      "$_path" "${@:2}" && return 0 || return $?
    fi
  done
  printf >&2 "\e[1;31mExecutable '%s' not found.\e[0m\n\e[0;31mChecked locations" "$1"
  printf >&2 " for formulas \e[1m%s\e[0;31m and \e[1mcoreutils\e[0;31m:\e[0m\n" "$1"
  printf >&2 "\e[31m  ⁃ %b\n" "${_paths[@]}"
  printf >&2 "\e[31m%s\e[0m\n" "$(brew --prefix "$1" 2>&1)"
  return 1
}

Because the built-in macOS programs are trash.

❌ Bad

$ find --version
find: illegal option -- -
usage: find [-H | -L | -P] [-EXdsx] [-f path] path ... [expression]
       find [-H | -L | -P] [-EXdsx] -f path [path ...] [expression]

emotional state: 😠

$ brew --prefix find
brew --prefix find
Error: No available formula with the name "find". Did you mean ffind, zfind or fend?

emotional state: 😡

---

✅ Good!

$ gnu find --version
find (GNU findutils) 4.10.0
Packaged by Homebrew
Copyright (C) 2024 Free Software Foundation, Inc.
[...]

emotional state: 😇