brew install

brew_install.sh

#!/bin/bash
set -u

abort() {
  printf "%s\n" "$@"
  exit 1
}

if [ -z "${BASH_VERSION:-}" ]; then
  abort "Bash is required to interpret this script."
fi

# Check if script is run non-interactively (e.g. CI)
# If it is run non-interactively we should not prompt for passwords.
if [[ ! -t 0 || -n "${CI-}" ]]; then
  NONINTERACTIVE=1
fi

# First check OS.
OS="$(uname)"
if [[ "$OS" == "Linux" ]]; then
  HOMEBREW_ON_LINUX=1
elif [[ "$OS" != "Darwin" ]]; then
  abort "Homebrew is only supported on macOS and Linux."
fi

# Required installation paths. To install elsewhere (which is unsupported)
# you can untar https://github.com/Homebrew/brew/tarball/master
# anywhere you like.
if [[ -z "${HOMEBREW_ON_LINUX-}" ]]; then
  UNAME_MACHINE="$(/usr/bin/uname -m)"

  if [[ "$UNAME_MACHINE" == "arm64" ]]; then
    # On ARM macOS, this script installs to /opt/homebrew only
    HOMEBREW_PREFIX="/opt/homebrew"
    HOMEBREW_REPOSITORY="${HOMEBREW_PREFIX}"
  else
    # On Intel macOS, this script installs to /usr/local only
    HOMEBREW_PREFIX="/usr/local"
    HOMEBREW_REPOSITORY="${HOMEBREW_PREFIX}/Homebrew"
  fi
  HOMEBREW_CACHE="${HOME}/Library/Caches/Homebrew"
  HOMEBREW_CORE_DEFAULT_GIT_REMOTE="https://github.com/Homebrew/homebrew-core"

  STAT="stat -f"
  CHOWN="/usr/sbin/chown"
  CHGRP="/usr/bin/chgrp"
  GROUP="admin"
  TOUCH="/usr/bin/touch"
else
  UNAME_MACHINE="$(uname -m)"

  # On Linux, it installs to /home/linuxbrew/.linuxbrew if you have sudo access
  # and ~/.linuxbrew (which is unsupported) if run interactively.
  HOMEBREW_PREFIX_DEFAULT="/home/linuxbrew/.linuxbrew"
  HOMEBREW_CACHE="${HOME}/.cache/Homebrew"
  HOMEBREW_CORE_DEFAULT_GIT_REMOTE="https://github.com/Homebrew/linuxbrew-core"

  STAT="stat --printf"
  CHOWN="/bin/chown"
  CHGRP="/bin/chgrp"
  GROUP="$(id -gn)"
  TOUCH="/bin/touch"
fi
HOMEBREW_BREW_DEFAULT_GIT_REMOTE="https://github.com/Homebrew/brew"

# Use remote URLs of Homebrew repositories from environment if set.
HOMEBREW_BREW_GIT_REMOTE="${HOMEBREW_BREW_GIT_REMOTE:-"${HOMEBREW_BREW_DEFAULT_GIT_REMOTE}"}"
HOMEBREW_CORE_GIT_REMOTE="${HOMEBREW_CORE_GIT_REMOTE:-"${HOMEBREW_CORE_DEFAULT_GIT_REMOTE}"}"
# The URLs with and without the '.git' suffix are the same Git remote. Do not prompt.
if [[ "$HOMEBREW_BREW_GIT_REMOTE" == "${HOMEBREW_BREW_DEFAULT_GIT_REMOTE}.git" ]]; then
  HOMEBREW_BREW_GIT_REMOTE="${HOMEBREW_BREW_DEFAULT_GIT_REMOTE}"
fi
if [[ "$HOMEBREW_CORE_GIT_REMOTE" == "${HOMEBREW_CORE_DEFAULT_GIT_REMOTE}.git" ]]; then
  HOMEBREW_CORE_GIT_REMOTE="${HOMEBREW_CORE_DEFAULT_GIT_REMOTE}"
fi
export HOMEBREW_{BREW,CORE}_GIT_REMOTE

# TODO: bump version when new macOS is released or announced
MACOS_NEWEST_UNSUPPORTED="12.0"
# TODO: bump version when new macOS is released
MACOS_OLDEST_SUPPORTED="10.14"

# For Homebrew on Linux
REQUIRED_RUBY_VERSION=2.6  # https://github.com/Homebrew/brew/pull/6556
REQUIRED_GLIBC_VERSION=2.13  # https://docs.brew.sh/Homebrew-on-Linux#requirements

# no analytics during installation
export HOMEBREW_NO_ANALYTICS_THIS_RUN=1
export HOMEBREW_NO_ANALYTICS_MESSAGE_OUTPUT=1

# string formatters
if [[ -t 1 ]]; then
  tty_escape() { printf "\033[%sm" "$1"; }
else
  tty_escape() { :; }
fi
tty_mkbold() { tty_escape "1;$1"; }
tty_underline="$(tty_escape "4;39")"
tty_blue="$(tty_mkbold 34)"
tty_red="$(tty_mkbold 31)"
tty_bold="$(tty_mkbold 39)"
tty_reset="$(tty_escape 0)"

have_sudo_access() {
  local -a args
  if [[ -n "${SUDO_ASKPASS-}" ]]; then
    args=("-A")
  elif [[ -n "${NONINTERACTIVE-}" ]]; then
    args=("-n")
  fi

  if [[ -z "${HAVE_SUDO_ACCESS-}" ]]; then
    if [[ -n "${args[*]-}" ]]; then
      SUDO="/usr/bin/sudo ${args[*]}"
    else
      SUDO="/usr/bin/sudo"
    fi
    if [[ -n "${NONINTERACTIVE-}" ]]; then
      ${SUDO} -l mkdir &>/dev/null
    else
      ${SUDO} -v && ${SUDO} -l mkdir &>/dev/null
    fi
    HAVE_SUDO_ACCESS="$?"
  fi

  if [[ -z "${HOMEBREW_ON_LINUX-}" ]] && [[ "$HAVE_SUDO_ACCESS" -ne 0 ]]; then
    abort "Need sudo access on macOS (e.g. the user $USER needs to be an Administrator)!"
  fi

  return "$HAVE_SUDO_ACCESS"
}

shell_join() {
  local arg
  printf "%s" "$1"
  shift
  for arg in "$@"; do
    printf " "
    printf "%s" "${arg// /\ }"
  done
}

chomp() {
  printf "%s" "${1/"$'\n'"/}"
}

ohai() {
  printf "${tty_blue}==>${tty_bold} %s${tty_reset}\n" "$(shell_join "$@")"
}

warn() {
  printf "${tty_red}Warning${tty_reset}: %s\n" "$(chomp "$1")"
}

execute() {
  if ! "$@"; then
    abort "$(printf "Failed during: %s" "$(shell_join "$@")")"
  fi
}

execute_sudo() {
  local -a args=("$@")
  if have_sudo_access; then
    if [[ -n "${SUDO_ASKPASS-}" ]]; then
      args=("-A" "${args[@]}")
    fi
    ohai "/usr/bin/sudo" "${args[@]}"
    execute "/usr/bin/sudo" "${args[@]}"
  else
    ohai "${args[@]}"
    execute "${args[@]}"
  fi
}

getc() {
  local save_state
  save_state=$(/bin/stty -g)
  /bin/stty raw -echo
  IFS= read -r -n 1 -d '' "$@"
  /bin/stty "$save_state"
}

ring_bell() {
  # Use the shell's audible bell.
  if [[ -t 1 ]]; then
    printf "\a"
  fi
}

wait_for_user() {
  local c
  echo
  echo "Press RETURN to continue or any other key to abort"
  getc c
  # we test for \r and \n because some stuff does \r instead
  if ! [[ "$c" == $'\r' || "$c" == $'\n' ]]; then
    exit 1
  fi
}

major_minor() {
  echo "${1%%.*}.$(x="${1#*.}"; echo "${x%%.*}")"
}

version_gt() {
  [[ "${1%.*}" -gt "${2%.*}" ]] || [[ "${1%.*}" -eq "${2%.*}" && "${1#*.}" -gt "${2#*.}" ]]
}
version_ge() {
  [[ "${1%.*}" -gt "${2%.*}" ]] || [[ "${1%.*}" -eq "${2%.*}" && "${1#*.}" -ge "${2#*.}" ]]
}
version_lt() {
  [[ "${1%.*}" -lt "${2%.*}" ]] || [[ "${1%.*}" -eq "${2%.*}" && "${1#*.}" -lt "${2#*.}" ]]
}

should_install_command_line_tools() {
  if [[ -n "${HOMEBREW_ON_LINUX-}" ]]; then
    return 1
  fi

  if version_gt "$macos_version" "10.13"; then
    ! [[ -e "/Library/Developer/CommandLineTools/usr/bin/git" ]]
  else
    ! [[ -e "/Library/Developer/CommandLineTools/usr/bin/git" ]] ||
      ! [[ -e "/usr/include/iconv.h" ]]
  fi
}

get_permission() {
  $STAT "%A" "$1"
}

user_only_chmod() {
  [[ -d "$1" ]] && [[ "$(get_permission "$1")" != "755" ]]
}

exists_but_not_writable() {
  [[ -e "$1" ]] && ! [[ -r "$1" && -w "$1" && -x "$1" ]]
}

get_owner() {
  $STAT "%u" "$1"
}

file_not_owned() {
  [[ "$(get_owner "$1")" != "$(id -u)" ]]
}

get_group() {
  $STAT "%g" "$1"
}

file_not_grpowned() {
  [[ " $(id -G "$USER") " != *" $(get_group "$1") "*  ]]
}

# Please sync with 'test_ruby()' in 'Library/Homebrew/utils/ruby.sh' from Homebrew/brew repository.
test_ruby() {
  if [[ ! -x $1 ]]
  then
    return 1
  fi

  "$1" --enable-frozen-string-literal --disable=gems,did_you_mean,rubyopt -rrubygems -e \
    "abort if Gem::Version.new(RUBY_VERSION.to_s.dup).to_s.split('.').first(2) != \
              Gem::Version.new('$REQUIRED_RUBY_VERSION').to_s.split('.').first(2)" 2>/dev/null
}

no_usable_ruby() {
  local ruby_exec
  IFS=$'\n' # Do word splitting on new lines only
  for ruby_exec in $(which -a ruby 2>/dev/null); do
    if test_ruby "$ruby_exec"; then
      IFS=$' \t\n' # Restore IFS to its default value
      return 1
    fi
  done
  IFS=$' \t\n' # Restore IFS to its default value
  return 0
}

outdated_glibc() {
  local glibc_version
  glibc_version=$(ldd --version | head -n1 | grep -o '[0-9.]*$' | grep -o '^[0-9]\+\.[0-9]\+')
  version_lt "$glibc_version" "$REQUIRED_GLIBC_VERSION"
}

if [[ -n "${HOMEBREW_ON_LINUX-}" ]] && no_usable_ruby && outdated_glibc
then
    abort "$(cat <<-EOFABORT
	Homebrew requires Ruby $REQUIRED_RUBY_VERSION which was not found on your system.
	Homebrew portable Ruby requires Glibc version $REQUIRED_GLIBC_VERSION or newer,
	and your Glibc version is too old.
	See ${tty_underline}https://docs.brew.sh/Homebrew-on-Linux#requirements${tty_reset}
	Install Ruby $REQUIRED_RUBY_VERSION and add its location to your PATH.
	EOFABORT
    )"
fi

# USER isn't always set so provide a fall back for the installer and subprocesses.
if [[ -z "${USER-}" ]]; then
  USER="$(chomp "$(id -un)")"
  export USER
fi

# Invalidate sudo timestamp before exiting (if it wasn't active before).
if ! /usr/bin/sudo -n -v 2>/dev/null; then
  trap '/usr/bin/sudo -k' EXIT
fi

# Things can fail later if `pwd` doesn't exist.
# Also sudo prints a warning message for no good reason
cd "/usr" || exit 1

####################################################################### script
if ! command -v git >/dev/null; then
    abort "$(cat <<EOABORT
You must install Git before installing Homebrew. See:
  ${tty_underline}https://docs.brew.sh/Installation${tty_reset}
EOABORT
)"
fi

if ! command -v curl >/dev/null; then
    abort "$(cat <<EOABORT
You must install cURL before installing Homebrew. See:
  ${tty_underline}https://docs.brew.sh/Installation${tty_reset}
EOABORT
)"
fi

# shellcheck disable=SC2016
ohai 'Checking for `sudo` access (which may request your password).'

if [[ -z "${HOMEBREW_ON_LINUX-}" ]]; then
  have_sudo_access
else
  if [[ -n "${NONINTERACTIVE-}" ]] ||
     [[ -w "${HOMEBREW_PREFIX_DEFAULT}" ]] ||
     [[ -w "/home/linuxbrew" ]] ||
     [[ -w "/home" ]]; then
    HOMEBREW_PREFIX="$HOMEBREW_PREFIX_DEFAULT"
  else
    trap exit SIGINT
    if ! /usr/bin/sudo -n -v &>/dev/null; then
      ohai "Select the Homebrew installation directory"
      echo "- ${tty_bold}Enter your password${tty_reset} to install to ${tty_underline}${HOMEBREW_PREFIX_DEFAULT}${tty_reset} (${tty_bold}recommended${tty_reset})"
      echo "- ${tty_bold}Press Control-D${tty_reset} to install to ${tty_underline}$HOME/.linuxbrew${tty_reset}"
      echo "- ${tty_bold}Press Control-C${tty_reset} to cancel installation"
    fi
    if have_sudo_access; then
      HOMEBREW_PREFIX="$HOMEBREW_PREFIX_DEFAULT"
    else
      HOMEBREW_PREFIX="$HOME/.linuxbrew"
    fi
    trap - SIGINT
  fi
  HOMEBREW_REPOSITORY="${HOMEBREW_PREFIX}/Homebrew"
fi
HOMEBREW_CORE="${HOMEBREW_REPOSITORY}/Library/Taps/homebrew/homebrew-core"

if [[ "${EUID:-${UID}}" == "0" ]]; then
  abort "Don't run this as root!"
elif [[ -d "${HOMEBREW_PREFIX}" && ! -x "${HOMEBREW_PREFIX}" ]]; then
  abort "$(cat <<EOABORT
The Homebrew prefix, ${HOMEBREW_PREFIX}, exists but is not searchable.
If this is not intentional, please restore the default permissions and
try running the installer again:
    sudo chmod 775 ${HOMEBREW_PREFIX}
EOABORT
)"
fi

if [[ -z "${HOMEBREW_ON_LINUX-}" ]]; then
  # On macOS, support 64-bit Intel and ARM
  if [[ "$UNAME_MACHINE" != "arm64" ]] && [[ "$UNAME_MACHINE" != "x86_64" ]]; then
    abort "Homebrew is only supported on Intel and ARM processors!"
  fi
else
  # On Linux, support only 64-bit Intel
  if [[ "$UNAME_MACHINE" == "arm64" ]]; then
    abort "$(cat <<EOABORT
Homebrew on Linux is not supported on ARM processors.
You can try an alternate installation method instead:
  ${tty_underline}https://docs.brew.sh/Homebrew-on-Linux#arm${tty_reset}
EOABORT
)"
  elif [[ "$UNAME_MACHINE" != "x86_64" ]]; then
    abort "Homebrew on Linux is only supported on Intel processors!"
  fi
fi

if [[ -z "${HOMEBREW_ON_LINUX-}" ]]; then
  macos_version="$(major_minor "$(/usr/bin/sw_vers -productVersion)")"
  if version_lt "$macos_version" "10.7"; then
    abort "$(cat <<EOABORT
Your Mac OS X version is too old. See:
  ${tty_underline}https://github.com/mistydemeo/tigerbrew${tty_reset}
EOABORT
)"
  elif version_lt "$macos_version" "10.10"; then
    abort "Your OS X version is too old"
  elif version_ge "$macos_version" "$MACOS_NEWEST_UNSUPPORTED" || \
    version_lt "$macos_version" "$MACOS_OLDEST_SUPPORTED"; then
    who="We"
    what=""
    if version_ge "$macos_version" "$MACOS_NEWEST_UNSUPPORTED"; then
      what="pre-release version"
    else
      who+=" (and Apple)"
      what="old version"
    fi
    ohai "You are using macOS ${macos_version}."
    ohai "${who} do not provide support for this ${what}."

    echo "$(cat <<EOS
This installation may not succeed.
After installation, you will encounter build failures with some formulae.
Please create pull requests instead of asking for help on Homebrew\'s GitHub,
Twitter or IRC. You are responsible for resolving any issues you experience
while you are running this ${what}.
EOS
)
"
  fi
fi

ohai "This script will install:"
echo "${HOMEBREW_PREFIX}/bin/brew"
echo "${HOMEBREW_PREFIX}/share/doc/homebrew"
echo "${HOMEBREW_PREFIX}/share/man/man1/brew.1"
echo "${HOMEBREW_PREFIX}/share/zsh/site-functions/_brew"
echo "${HOMEBREW_PREFIX}/etc/bash_completion.d/brew"
echo "${HOMEBREW_REPOSITORY}"

# Keep relatively in sync with
# https://github.com/Homebrew/brew/blob/master/Library/Homebrew/keg.rb
directories=(bin etc include lib sbin share opt var
             Frameworks
             etc/bash_completion.d lib/pkgconfig
             share/aclocal share/doc share/info share/locale share/man
             share/man/man1 share/man/man2 share/man/man3 share/man/man4
             share/man/man5 share/man/man6 share/man/man7 share/man/man8
             var/log var/homebrew var/homebrew/linked
             bin/brew)
group_chmods=()
for dir in "${directories[@]}"; do
  if exists_but_not_writable "${HOMEBREW_PREFIX}/${dir}"; then
    group_chmods+=("${HOMEBREW_PREFIX}/${dir}")
  fi
done

# zsh refuses to read from these directories if group writable
directories=(share/zsh share/zsh/site-functions)
zsh_dirs=()
for dir in "${directories[@]}"; do
  zsh_dirs+=("${HOMEBREW_PREFIX}/${dir}")
done

directories=(bin etc include lib sbin share var opt
             share/zsh share/zsh/site-functions
             var/homebrew var/homebrew/linked
             Cellar Caskroom Frameworks)
mkdirs=()
for dir in "${directories[@]}"; do
  if ! [[ -d "${HOMEBREW_PREFIX}/${dir}" ]]; then
    mkdirs+=("${HOMEBREW_PREFIX}/${dir}")
  fi
done

user_chmods=()
if [[ "${#zsh_dirs[@]}" -gt 0 ]]; then
  for dir in "${zsh_dirs[@]}"; do
    if user_only_chmod "${dir}"; then
      user_chmods+=("${dir}")
    fi
  done
fi

chmods=()
if [[ "${#group_chmods[@]}" -gt 0 ]]; then
  chmods+=("${group_chmods[@]}")
fi
if [[ "${#user_chmods[@]}" -gt 0 ]]; then
  chmods+=("${user_chmods[@]}")
fi

chowns=()
chgrps=()
if [[ "${#chmods[@]}" -gt 0 ]]; then
  for dir in "${chmods[@]}"; do
    if file_not_owned "${dir}"; then
      chowns+=("${dir}")
    fi
    if file_not_grpowned "${dir}"; then
      chgrps+=("${dir}")
    fi
  done
fi

if [[ "${#group_chmods[@]}" -gt 0 ]]; then
  ohai "The following existing directories will be made group writable:"
  printf "%s\n" "${group_chmods[@]}"
fi
if [[ "${#user_chmods[@]}" -gt 0 ]]; then
  ohai "The following existing directories will be made writable by user only:"
  printf "%s\n" "${user_chmods[@]}"
fi
if [[ "${#chowns[@]}" -gt 0 ]]; then
  ohai "The following existing directories will have their owner set to ${tty_underline}${USER}${tty_reset}:"
  printf "%s\n" "${chowns[@]}"
fi
if [[ "${#chgrps[@]}" -gt 0 ]]; then
  ohai "The following existing directories will have their group set to ${tty_underline}${GROUP}${tty_reset}:"
  printf "%s\n" "${chgrps[@]}"
fi
if [[ "${#mkdirs[@]}" -gt 0 ]]; then
  ohai "The following new directories will be created:"
  printf "%s\n" "${mkdirs[@]}"
fi

if should_install_command_line_tools; then
  ohai "The Xcode Command Line Tools will be installed."
fi

non_default_repos=""
additional_shellenv_commands=()
if [[ "$HOMEBREW_BREW_DEFAULT_GIT_REMOTE" != "$HOMEBREW_BREW_GIT_REMOTE" ]]; then
  ohai "HOMEBREW_BREW_GIT_REMOTE is set to a non-default URL:"
  echo "${tty_underline}${HOMEBREW_BREW_GIT_REMOTE}${tty_reset} will be used for Homebrew/brew Git remote."
  non_default_repos="Homebrew/brew"
  additional_shellenv_commands+=("export HOMEBREW_BREW_GIT_REMOTE=\"$HOMEBREW_BREW_GIT_REMOTE\"")
fi

if [[ "$HOMEBREW_CORE_DEFAULT_GIT_REMOTE" != "$HOMEBREW_CORE_GIT_REMOTE" ]]; then
  ohai "HOMEBREW_CORE_GIT_REMOTE is set to a non-default URL:"
  echo "${tty_underline}${HOMEBREW_CORE_GIT_REMOTE}${tty_reset} will be used for Homebrew/core Git remote."
  non_default_repos="${non_default_repos:-}${non_default_repos:+ and }Homebrew/core"
  additional_shellenv_commands+=("export HOMEBREW_CORE_GIT_REMOTE=\"$HOMEBREW_CORE_GIT_REMOTE\"")
fi

if [[ -z "${NONINTERACTIVE-}" ]]; then
  ring_bell
  wait_for_user
fi

if [[ -d "${HOMEBREW_PREFIX}" ]]; then
  if [[ "${#chmods[@]}" -gt 0 ]]; then
    execute_sudo "/bin/chmod" "u+rwx" "${chmods[@]}"
  fi
  if [[ "${#group_chmods[@]}" -gt 0 ]]; then
    execute_sudo "/bin/chmod" "g+rwx" "${group_chmods[@]}"
  fi
  if [[ "${#user_chmods[@]}" -gt 0 ]]; then
    execute_sudo "/bin/chmod" "755" "${user_chmods[@]}"
  fi
  if [[ "${#chowns[@]}" -gt 0 ]]; then
    execute_sudo "$CHOWN" "$USER" "${chowns[@]}"
  fi
  if [[ "${#chgrps[@]}" -gt 0 ]]; then
    execute_sudo "$CHGRP" "$GROUP" "${chgrps[@]}"
  fi
else
  execute_sudo "/bin/mkdir" "-p" "${HOMEBREW_PREFIX}"
  if [[ -z "${HOMEBREW_ON_LINUX-}" ]]; then
    execute_sudo "$CHOWN" "root:wheel" "${HOMEBREW_PREFIX}"
  else
    execute_sudo "$CHOWN" "$USER:$GROUP" "${HOMEBREW_PREFIX}"
  fi
fi

if [[ "${#mkdirs[@]}" -gt 0 ]]; then
  execute_sudo "/bin/mkdir" "-p" "${mkdirs[@]}"
  execute_sudo "/bin/chmod" "g+rwx" "${mkdirs[@]}"
  execute_sudo "$CHOWN" "$USER" "${mkdirs[@]}"
  execute_sudo "$CHGRP" "$GROUP" "${mkdirs[@]}"
fi

if ! [[ -d "${HOMEBREW_REPOSITORY}" ]]; then
  execute_sudo "/bin/mkdir" "-p" "${HOMEBREW_REPOSITORY}"
fi
execute_sudo "$CHOWN" "-R" "$USER:$GROUP" "${HOMEBREW_REPOSITORY}"

if ! [[ -d "${HOMEBREW_CACHE}" ]]; then
  if [[ -z "${HOMEBREW_ON_LINUX-}" ]]; then
    execute_sudo "/bin/mkdir" "-p" "${HOMEBREW_CACHE}"
  else
    execute "/bin/mkdir" "-p" "${HOMEBREW_CACHE}"
  fi
fi
if exists_but_not_writable "${HOMEBREW_CACHE}"; then
  execute_sudo "/bin/chmod" "g+rwx" "${HOMEBREW_CACHE}"
fi
if file_not_owned "${HOMEBREW_CACHE}"; then
  execute_sudo "$CHOWN" "-R" "$USER" "${HOMEBREW_CACHE}"
fi
if file_not_grpowned "${HOMEBREW_CACHE}"; then
  execute_sudo "$CHGRP" "-R" "$GROUP" "${HOMEBREW_CACHE}"
fi
if [[ -d "${HOMEBREW_CACHE}" ]]; then
  execute "$TOUCH" "${HOMEBREW_CACHE}/.cleaned"
fi

if should_install_command_line_tools && version_ge "$macos_version" "10.13"; then
  ohai "Searching online for the Command Line Tools"
  # This temporary file prompts the 'softwareupdate' utility to list the Command Line Tools
  clt_placeholder="/tmp/.com.apple.dt.CommandLineTools.installondemand.in-progress"
  execute_sudo "$TOUCH" "$clt_placeholder"

  clt_label_command="/usr/sbin/softwareupdate -l |
                      grep -B 1 -E 'Command Line Tools' |
                      awk -F'*' '/^ *\\*/ {print \$2}' |
                      sed -e 's/^ *Label: //' -e 's/^ *//' |
                      sort -V |
                      tail -n1"
  clt_label="$(chomp "$(/bin/bash -c "$clt_label_command")")"

  if [[ -n "$clt_label" ]]; then
    ohai "Installing $clt_label"
    execute_sudo "/usr/sbin/softwareupdate" "-i" "$clt_label"
    execute_sudo "/bin/rm" "-f" "$clt_placeholder"
    execute_sudo "/usr/bin/xcode-select" "--switch" "/Library/Developer/CommandLineTools"
  fi
fi

# Headless install may have failed, so fallback to original 'xcode-select' method
if should_install_command_line_tools && test -t 0; then
  ohai "Installing the Command Line Tools (expect a GUI popup):"
  execute_sudo "/usr/bin/xcode-select" "--install"
  echo "Press any key when the installation has completed."
  getc
  execute_sudo "/usr/bin/xcode-select" "--switch" "/Library/Developer/CommandLineTools"
fi

if [[ -z "${HOMEBREW_ON_LINUX-}" ]] && ! output="$(/usr/bin/xcrun clang 2>&1)" && [[ "$output" == *"license"* ]]; then
  abort "$(cat <<EOABORT
You have not agreed to the Xcode license.
Before running the installer again please agree to the license by opening
Xcode.app or running:
    sudo xcodebuild -license
EOABORT
)"
fi

ohai "Downloading and installing Homebrew..."
(
  cd "${HOMEBREW_REPOSITORY}" >/dev/null || return

  # we do it in four steps to avoid merge errors when reinstalling
  execute "git" "init" "-q"

  # "git remote add" will fail if the remote is defined in the global config
  execute "git" "config" "remote.origin.url" "${HOMEBREW_BREW_GIT_REMOTE}"
  execute "git" "config" "remote.origin.fetch" "+refs/heads/*:refs/remotes/origin/*"

  # ensure we don't munge line endings on checkout
  execute "git" "config" "core.autocrlf" "false"

  execute "git" "fetch" "--force" "origin"
  execute "git" "fetch" "--force" "--tags" "origin"

  execute "git" "reset" "--hard" "origin/master"

  if [[ "${HOMEBREW_REPOSITORY}" != "${HOMEBREW_PREFIX}" ]]; then
    execute "ln" "-sf" "${HOMEBREW_REPOSITORY}/bin/brew" "${HOMEBREW_PREFIX}/bin/brew"
  fi

  if [[ ! -d "${HOMEBREW_CORE}" ]]; then
    ohai "Tapping homebrew/core"
    (
      execute "/bin/mkdir" "-p" "${HOMEBREW_CORE}"
      cd "${HOMEBREW_CORE}" >/dev/null || return

      execute "git" "init" "-q"
      execute "git" "config" "remote.origin.url" "${HOMEBREW_CORE_GIT_REMOTE}"
      execute "git" "config" "remote.origin.fetch" "+refs/heads/*:refs/remotes/origin/*"
      execute "git" "config" "core.autocrlf" "false"
      execute "git" "fetch" "--force" "origin" "refs/heads/master:refs/remotes/origin/master"
      execute "git" "remote" "set-head" "origin" "--auto" >/dev/null
      execute "git" "reset" "--hard" "origin/master"

      cd "${HOMEBREW_REPOSITORY}" >/dev/null || return
    ) || exit 1
  fi

  execute "${HOMEBREW_PREFIX}/bin/brew" "update" "--force" "--quiet"
) || exit 1

if [[ ":${PATH}:" != *":${HOMEBREW_PREFIX}/bin:"* ]]; then
  warn "${HOMEBREW_PREFIX}/bin is not in your PATH."
fi

ohai "Installation successful!"
echo

ring_bell

# Use an extra newline and bold to avoid this being missed.
ohai "Homebrew has enabled anonymous aggregate formulae and cask analytics."
echo "$(cat <<EOS
${tty_bold}Read the analytics documentation (and how to opt-out) here:
  ${tty_underline}https://docs.brew.sh/Analytics${tty_reset}
No analytics data has been sent yet (or will be during this \`install\` run).
EOS
)
"

ohai "Homebrew is run entirely by unpaid volunteers. Please consider donating:"
echo "$(cat <<EOS
  ${tty_underline}https://github.com/Homebrew/brew#donations${tty_reset}
EOS
)
"

(
  cd "${HOMEBREW_REPOSITORY}" >/dev/null || return
  execute "git" "config" "--replace-all" "homebrew.analyticsmessage" "true"
  execute "git" "config" "--replace-all" "homebrew.caskanalyticsmessage" "true"
) || exit 1

ohai "Next steps:"
case "$SHELL" in
  */bash*)
    if [[ -r "$HOME/.bash_profile" ]]; then
      shell_profile="$HOME/.bash_profile"
    else
      shell_profile="$HOME/.profile"
    fi
    ;;
  */zsh*)
    shell_profile="$HOME/.zprofile"
    ;;
  *)
    shell_profile="$HOME/.profile"
    ;;
esac
if [[ "$UNAME_MACHINE" == "arm64" ]] || [[ -n "${HOMEBREW_ON_LINUX-}" ]]; then
  cat <<EOS
- Add Homebrew to your ${tty_bold}PATH${tty_reset} in ${tty_underline}${shell_profile}${tty_reset}:
    echo 'eval "\$(${HOMEBREW_PREFIX}/bin/brew shellenv)"' >> ${shell_profile}
    eval "\$(${HOMEBREW_PREFIX}/bin/brew shellenv)"
EOS
fi
if [[ -n "${non_default_repos}" ]]; then
  s=""
  if [[ "${#additional_shellenv_commands[@]}" -gt 1 ]]; then
    s="s"
  fi
  echo "- Add the non-default Git remote${s} for ${non_default_repos} in ${tty_underline}${shell_profile}${tty_reset}:"
  printf "    echo '%s' >> ${shell_profile}\n" "${additional_shellenv_commands[@]}"
  printf "    %s\n" "${additional_shellenv_commands[@]}"
fi

echo "- Run \`brew help\` to get started"
echo "- Further documentation: "
echo "    ${tty_underline}https://docs.brew.sh${tty_reset}"

if [[ -n "${HOMEBREW_ON_LINUX-}" ]]; then
  echo "- Install the Homebrew dependencies if you have sudo access:"

  if [[ $(command -v apt-get) ]]; then
    echo "    sudo apt-get install build-essential"
  elif [[ $(command -v yum) ]]; then
    echo "    sudo yum groupinstall 'Development Tools'"
  elif [[ $(command -v pacman) ]]; then
    echo "    sudo pacman -S base-devel"
  elif [[ $(command -v apk) ]]; then
    echo "    sudo apk add build-base"
  fi

  cat <<EOS
    See ${tty_underline}https://docs.brew.sh/linux${tty_reset} for more information
- We recommend that you install GCC:
    brew install gcc

EOS
fi