bin/brew: move logic to Library.

`bin/brew` is getting a bit bloated and it's annoying to open all of
`HOMEBREW_PREFIX` in your editor of choice and have it search through
the `Cellar`. Let's instead keep the bare minimum in `bin/brew` and
move the rest to `Library`.

Closes Homebrew/homebrew#49185.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>

1 files changed, 172 insertions, 0 deletions

diff --git a/Library/brew.sh b/Library/brew.sh
new file mode 100644
index 000000000..015ee17e5
--- /dev/null
+++ b/Library/brew.sh
@@ -0,0 +1,172 @@
+odie() {
+  if [[ -t 2 ]] # check whether stderr is a tty.
+  then
+    echo -ne "\033[4;31mError\033[0m: " >&2 # highlight Error with underline and red color
+  else
+    echo -n "Error: " >&2
+  fi
+  if [[ $# -eq 0 ]]
+  then
+    /bin/cat >&2
+  else
+    echo "$*" >&2
+  fi
+  exit 1
+}
+
+chdir() {
+  cd "$@" >/dev/null || odie "Error: failed to cd to $*!"
+}
+
+# Force UTF-8 to avoid encoding issues for users with broken locale settings.
+if [[ "$(locale charmap 2> /dev/null)" != "UTF-8" ]]
+then
+  export LC_ALL="en_US.UTF-8"
+fi
+
+# Where we store built products; /usr/local/Cellar if it exists,
+# otherwise a Cellar relative to the Repository.
+if [[ -d "$HOMEBREW_PREFIX/Cellar" ]]
+then
+  HOMEBREW_CELLAR="$HOMEBREW_PREFIX/Cellar"
+else
+  HOMEBREW_CELLAR="$HOMEBREW_REPOSITORY/Cellar"
+fi
+
+case "$*" in
+  --prefix) echo "$HOMEBREW_PREFIX"; exit 0 ;;
+  --cellar) echo "$HOMEBREW_CELLAR"; exit 0 ;;
+  --repository|--repo) echo "$HOMEBREW_REPOSITORY"; exit 0 ;;
+esac
+
+if [[ "$HOMEBREW_PREFIX" = "/" || "$HOMEBREW_PREFIX" = "/usr" ]]
+then
+  # it may work, but I only see pain this route and don't want to support it
+  odie "Cowardly refusing to continue at this prefix: $HOMEBREW_PREFIX"
+fi
+
+# Users may have these set, pointing the system Ruby
+# at non-system gem paths
+unset GEM_HOME
+unset GEM_PATH
+
+if [[ -z "$HOMEBREW_DEVELOPER" ]]
+then
+  unset HOMEBREW_RUBY_PATH
+fi
+
+if [[ "$(uname -s)" = "Darwin" ]]
+then
+  HOMEBREW_OSX="1"
+fi
+
+if [[ -z "$HOMEBREW_RUBY_PATH" ]]
+then
+  if [[ -n "$HOMEBREW_OSX" ]]
+  then
+    HOMEBREW_RUBY_PATH="/System/Library/Frameworks/Ruby.framework/Versions/Current/usr/bin/ruby"
+  else
+    HOMEBREW_RUBY_PATH="$(which ruby)"
+  fi
+fi
+
+export HOMEBREW_BREW_FILE
+export HOMEBREW_RUBY_PATH
+export HOMEBREW_PREFIX
+export HOMEBREW_REPOSITORY
+export HOMEBREW_LIBRARY
+export HOMEBREW_CELLAR
+
+if [[ -n "$HOMEBREW_OSX" ]]
+then
+  if [[ "$('/usr/bin/xcode-select' --print-path)" = "/" ]]
+  then
+    odie <<EOS
+Your xcode-select path is currently set to '/'.
+This causes the 'xcrun' tool to hang, and can render Homebrew unusable.
+If you are using Xcode, you should:
+  sudo xcode-select -switch /Applications/Xcode.app
+Otherwise, you should:
+  sudo rm -rf /usr/share/xcode-select
+EOS
+  fi
+
+  XCRUN_OUTPUT="$(/usr/bin/xcrun clang 2>&1)"
+  XCRUN_STATUS="$?"
+
+  if [[ "$XCRUN_STATUS" -ne 0 && "$XCRUN_OUTPUT" = *license* ]]
+  then
+    odie <<EOS
+You have not agreed to the Xcode license. Please resolve this by running:
+  sudo xcodebuild -license
+EOS
+  fi
+fi
+
+# Many Pathname operations use getwd when they shouldn't, and then throw
+# odd exceptions. Reduce our support burden by showing a user-friendly error.
+if [[ ! -d "$(pwd)" ]]
+then
+  odie "The current working directory doesn't exist, cannot proceed."
+fi
+
+if [[ "$1" = -v ]]
+then
+  # Shift the -v to the end of the parameter list
+  shift
+  set -- "$@" -v
+fi
+
+HOMEBREW_COMMAND="$1"
+shift
+case "$HOMEBREW_COMMAND" in
+  ls)          HOMEBREW_COMMAND="list";;
+  homepage)    HOMEBREW_COMMAND="home";;
+  -S)          HOMEBREW_COMMAND="search";;
+  up)          HOMEBREW_COMMAND="update";;
+  ln)          HOMEBREW_COMMAND="link";;
+  instal)      HOMEBREW_COMMAND="install";; # gem does the same
+  rm)          HOMEBREW_COMMAND="uninstall";;
+  remove)      HOMEBREW_COMMAND="uninstall";;
+  configure)   HOMEBREW_COMMAND="diy";;
+  abv)         HOMEBREW_COMMAND="info";;
+  dr)          HOMEBREW_COMMAND="doctor";;
+  --repo)      HOMEBREW_COMMAND="--repository";;
+  environment) HOMEBREW_COMMAND="--env";;
+  --config)    HOMEBREW_COMMAND="config";;
+esac
+
+if [[ -f "$HOMEBREW_LIBRARY/Homebrew/cmd/$HOMEBREW_COMMAND.sh" ]] ; then
+  HOMEBREW_BASH_COMMAND="$HOMEBREW_LIBRARY/Homebrew/cmd/$HOMEBREW_COMMAND.sh"
+elif [[ -n "$HOMEBREW_DEVELOPER" && -f "$HOMEBREW_LIBRARY/Homebrew/dev-cmd/$HOMEBREW_COMMAND.sh" ]] ; then
+  HOMEBREW_BASH_COMMAND="$HOMEBREW_LIBRARY/Homebrew/dev-cmd/$HOMEBREW_COMMAND.sh"
+fi
+
+if [[ "$(id -u)" = "0" && "$(/usr/bin/stat -f%u "$HOMEBREW_BREW_FILE")" != "0" ]]
+then
+  case "$HOMEBREW_COMMAND" in
+    install|reinstall|postinstall|link|pin|update|update-ruby|upgrade|create|migrate|tap|switch)
+      odie <<EOS
+Cowardly refusing to 'sudo brew $HOMEBREW_COMMAND'
+You can use brew with sudo, but only if the brew executable is owned by root.
+However, this is both not recommended and completely unsupported so do so at
+your own risk.
+EOS
+      ;;
+  esac
+fi
+
+if [[ -n "$HOMEBREW_BASH_COMMAND" ]]
+then
+  # source rather than executing directly to ensure the entire file is read into
+  # memory before it is run. This makes running a Bash script behave more like
+  # a Ruby script and avoids hard-to-debug issues if the Bash script is updated
+  # at the same time as being run.
+  #
+  # Hide shellcheck complaint:
+  # shellcheck source=/dev/null
+  source "$HOMEBREW_BASH_COMMAND"
+  { "homebrew-$HOMEBREW_COMMAND" "$@"; exit $?; }
+else
+  exec "$HOMEBREW_RUBY_PATH" -W0 "$HOMEBREW_LIBRARY/brew.rb" "$HOMEBREW_COMMAND" "$@"
+fi