Move some brew.rb logic to bin/brew.

Library/brew.rb

@@ -4,11 +4,6 @@ std_trap = trap("INT") { exit! 130 } # no backtrace thanks
 
 HOMEBREW_BREW_FILE = ENV["HOMEBREW_BREW_FILE"]
 
-if ARGV == %w[--prefix]
-  puts File.dirname(File.dirname(HOMEBREW_BREW_FILE))
-  exit 0
-end
-
 require "pathname"
 HOMEBREW_LIBRARY_PATH = Pathname.new(__FILE__).realpath.parent.join("Homebrew")
 $:.unshift(HOMEBREW_LIBRARY_PATH.to_s)
@@ -22,38 +17,6 @@ elsif ARGV.first == "-v"
   ARGV << ARGV.shift
 end
 
-if OS.mac?
-  # Check for bad xcode-select before other checks, because `doctor` and
-  # many other things will hang. Note that this bug was fixed in 10.9
-  if MacOS.version < :mavericks && MacOS.active_developer_dir == "/"
-    odie <<-EOS.undent
-      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
-  end
-
-  # Check for user agreement of the Xcode license before permitting
-  # any other brew usage to continue. This prevents the situation where
-  # people are instructed to "please re-run as root via sudo" on brew commands.
-  # The check can only fail when Xcode is installed & the active developer dir.
-  if MacOS::Xcode.installed? && `/usr/bin/xcrun clang 2>&1` =~ /license/ && !$?.success?
-    odie <<-EOS.undent
-      You have not agreed to the Xcode license. Please resolve this by running:
-        sudo xcodebuild -license
-    EOS
-  end
-end
-
-case HOMEBREW_PREFIX.to_s
-when "/", "/usr"
-  # it may work, but I only see pain this route and don't want to support it
-  abort "Cowardly refusing to continue at this prefix: #{HOMEBREW_PREFIX}"
-end
-
 if OS.mac? && MacOS.version < "10.6"
   abort <<-EOABORT.undent
     Homebrew requires Snow Leopard or higher. For Tiger and Leopard support, see:
@@ -61,10 +24,6 @@ if OS.mac? && MacOS.version < "10.6"
   EOABORT
 end
 
-# Many Pathname operations use getwd when they shouldn't, and then throw
-# odd exceptions. Reduce our support burden by showing a user-friendly error.
-Dir.getwd rescue abort "The current working directory doesn't exist, cannot proceed."
-
 def require?(path)
   require path
 rescue LoadError => e
@@ -94,20 +53,6 @@ begin
 
   cmd = HOMEBREW_INTERNAL_COMMAND_ALIASES.fetch(cmd, cmd)
 
-  sudo_check = %w[ install reinstall postinstall link pin unpin
-                   update upgrade create migrate tap switch ]
-
-  if sudo_check.include? cmd
-    if Process.uid.zero? && !File.stat(HOMEBREW_BREW_FILE).uid.zero?
-      raise <<-EOS.undent
-        Cowardly refusing to `sudo brew #{cmd}`
-        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
-    end
-  end
-
   # Add contributed commands to PATH before checking.
   Dir["#{HOMEBREW_LIBRARY}/Taps/*/*/cmd"].each do |tap_cmd_dir|
     ENV["PATH"] += "#{File::PATH_SEPARATOR}#{tap_cmd_dir}"

bin/brew

@@ -37,6 +37,19 @@ 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
+  echo "Cowardly refusing to continue at this prefix: $HOMEBREW_PREFIX" >&2
+  exit 1
+fi
+
 # Users may have these set, pointing the system Ruby
 # at non-system gem paths
 unset GEM_HOME
@@ -47,9 +60,14 @@ then
   unset HOMEBREW_RUBY_PATH
 fi
 
+if [ "$(uname -s)" = "Darwin" ]
+then
+  HOMEBREW_OSX="1"
+fi
+
 if [ -z "$HOMEBREW_RUBY_PATH" ]
 then
-  if [ "$(uname -s)" = "Darwin" ]
+  if [ -n "$HOMEBREW_OSX" ]
   then
     HOMEBREW_RUBY_PATH="/System/Library/Frameworks/Ruby.framework/Versions/Current/usr/bin/ruby"
   else
@@ -64,6 +82,42 @@ export HOMEBREW_REPOSITORY
 export HOMEBREW_LIBRARY
 export HOMEBREW_CELLAR
 
+if [ -n "$HOMEBREW_OSX" ]
+then
+  if [ "$('xcode-select' --print-path)" = "/" ]
+  then
+    cat >&2 <<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
+    exit 1
+  fi
+
+  XCRUN_OUTPUT="$(/usr/bin/xcrun clang 2>&1)"
+  XCRUN_STATUS="$?"
+
+  if [ "$XCRUN_STATUS" -ne 0 ] && [[ "$XCRUN_OUTPUT" = *license* ]]
+  then
+    cat >&2 <<EOS
+You have not agreed to the Xcode license. Please resolve this by running:
+  sudo xcodebuild -license
+EOS
+    exit 1
+  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 "$(pwd)" ]
+then
+  echo "The current working directory doesn't exist, cannot proceed." >&2
+  exit 1
+fi
+
 for i in "$@"
 do
   if [[ "$1" = -v ]]
@@ -72,10 +126,26 @@ do
     set -- "$@" -v
   fi
   [[ "$i" =~ ^- ]] && continue
+  HOMEBREW_COMMAND="$i"
   HOMEBREW_BASH_COMMAND="$HOMEBREW_LIBRARY/Homebrew/cmd/$i.sh"
   break
 done
 
+if [ "$(id -u)" = "0" ] && [ "$(stat -f%u "$HOMEBREW_BREW_FILE")" != "0" ]
+then
+  case "$HOMEBREW_COMMAND" in
+    install|reinstall|postinstall|link|pin|unpin|update|update-bash|upgrade|create|migrate|tap|switch)
+      cat >&2 <<EOS
+Cowardly refusing to 'sudo brew $HOMEBREW_COMMAND'
+You can use brew with sudo, but only if the brew executable is owned by root.
+However, this is both not recommended and completely unsupported so do so at
+your own risk.
+EOS
+      exit 1
+      ;;
+  esac
+fi
+
 if [ -n "$HOMEBREW_BASH_COMMAND" ] && [ -x "$HOMEBREW_BASH_COMMAND" ]
 then
   # source rather than executing directly to ensure the entire file is read into