cleanup: add an option to perform a 'dry run'

Sometimes you want to know what `brew cleanup` will do before it
actually removes anything. Introduce a '-n' option (chosen to match
other UNIX tools) to do this.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/Library/Homebrew/cmd/cleanup.rb b/Library/Homebrew/cmd/cleanup.rb
index 0f9f2c3cb..0aec10f56 100644
--- a/Library/Homebrew/cmd/cleanup.rb
+++ b/Library/Homebrew/cmd/cleanup.rb
@@ -13,7 +13,7 @@ module Homebrew extend self
         end
       end
       # seems like a good time to do some additional cleanup
-      Homebrew.prune
+      Homebrew.prune unless ARGV.include? '-n'
     else
       ARGV.formulae.each do |f|
         cleanup_formula f
@@ -36,7 +36,7 @@ module Homebrew extend self
       f.rack.children.each do |keg|
         if f.installed_prefix != keg
           print "Removing #{keg}..."
-          rm_rf keg
+          rm_rf keg unless ARGV.include? '-n'
           puts
         end
       end