#!/bin/bash

set +o posix

# Fail fast with concise message when cwd does not exist

if ! [[ -d "$PWD" ]]; then

echo "Error: The current working directory doesn't exist, cannot proceed." >&2

exit 1

fi

quiet_cd() {

cd "$@" >/dev/null || return

}

symlink_target_directory() {

local target target_dirname

target="$(readlink "$1")"

target_dirname="$(dirname "$target")"

local directory="$2"

quiet_cd "$directory" && quiet_cd "$target_dirname" && pwd -P

}

# Enable and use default Bash builtins rather than user-defined functions

builtin enable compgen unset

for cmd in $(builtin compgen -A builtin)

do

builtin unset -f $cmd

builtin enable $cmd

done

unset cmd

BREW_FILE_DIRECTORY="$(quiet_cd "${0%/*}/" && pwd -P)"

HOMEBREW_BREW_FILE="${BREW_FILE_DIRECTORY%/}/${0##*/}"

HOMEBREW_PREFIX="${HOMEBREW_BREW_FILE%/*/*}"

# Default to / prefix if unset or the bin/brew file.

if [[ -z "$HOMEBREW_PREFIX" || "$HOMEBREW_PREFIX" = "$HOMEBREW_BREW_FILE" ]]

then

HOMEBREW_PREFIX="/"

fi

HOMEBREW_REPOSITORY="$HOMEBREW_PREFIX"

# Resolve the bin/brew symlink to find Homebrew's repository

if [[ -L "$HOMEBREW_BREW_FILE" ]]

then

BREW_FILE_DIRECTORY="$(symlink_target_directory "$HOMEBREW_BREW_FILE" "$BREW_FILE_DIRECTORY")"

HOMEBREW_REPOSITORY="${BREW_FILE_DIRECTORY%/*}"

fi

# Try to find a /usr/local HOMEBREW_PREFIX where possible (for bottles)

if [[ -L "/usr/local/bin/brew" && ! -L "$HOMEBREW_PREFIX/Cellar" ]]

then

USR_LOCAL_BREW_FILE_DIRECTORY="$(symlink_target_directory "/usr/local/bin/brew" "/usr/local/bin")"

USR_LOCAL_HOMEBREW_REPOSITORY="${USR_LOCAL_BREW_FILE_DIRECTORY%/*}"

if [[ "$HOMEBREW_REPOSITORY" = "$USR_LOCAL_HOMEBREW_REPOSITORY" ]]

then

HOMEBREW_PREFIX="/usr/local"

fi

fi

HOMEBREW_LIBRARY="$HOMEBREW_REPOSITORY/Library"

# Whitelist and copy to HOMEBREW_* all variables previously mentioned in

# manpage or used elsewhere by Homebrew.

for VAR in AWS_ACCESS_KEY_ID AWS_SECRET_ACCESS_KEY BINTRAY_USER BINTRAY_KEY \

BROWSER DISPLAY EDITOR GIT NO_COLOR PATH VISUAL

do

# Skip if variable value is empty.

[[ -z "${!VAR}" ]] && continue

VAR_NEW="HOMEBREW_${VAR}"

# Skip if existing HOMEBREW_* variable is set.

[[ -n "${!VAR_NEW}" ]] && continue

export "$VAR_NEW"="${!VAR}"

done

# Set CI variable for GitHub Actions, Azure Pipelines, Jenkins

# (Set by default on Circle and Travis CI)

if [[ -n "$GITHUB_ACTIONS" || -n "$TF_BUILD" || -n "$JENKINS_HOME" ]]

then

export CI="1"

fi

# test-bot does environment filtering itself

if [[ -z "$HOMEBREW_NO_ENV_FILTERING" && "$1" != "test-bot" ]]

then

PATH="/usr/bin:/bin:/usr/sbin:/sbin"

FILTERED_ENV=()

# Filter all but the specific variables.

for VAR in HOME SHELL PATH TERM TERMINFO COLUMNS LOGNAME USER CI SSH_AUTH_SOCK SUDO_ASKPASS \

http_proxy https_proxy ftp_proxy no_proxy all_proxy HTTPS_PROXY FTP_PROXY ALL_PROXY \

"${!HOMEBREW_@}" "${!TRAVIS_@}"

do

# Skip if variable value is empty.

[[ -z "${!VAR}" ]] && continue

FILTERED_ENV+=( "${VAR}=${!VAR}" )

done

exec /usr/bin/env -i "${FILTERED_ENV[@]}" /bin/bash "$HOMEBREW_LIBRARY/Homebrew/brew.sh" "$@"

else

# Don't need shellcheck to follow this `source`.

# shellcheck disable=SC1090

source "$HOMEBREW_LIBRARY/Homebrew/brew.sh"

fi