Make generic caveats for launchd plist files.

Library/Homebrew/formula.rb

@@ -139,10 +139,13 @@ class Formula
   def var; HOMEBREW_PREFIX+'var' end
 
   # override this to provide a plist
-  def startup_plist; nil; end
+  def plist; nil; end
+  alias :startup_plist :plist
   # plist name, i.e. the name of the launchd service
   def plist_name; 'homebrew.mxcl.'+name end
   def plist_path; prefix+(plist_name+'.plist') end
+  def plist_manual; self.class.plist_manual end
+  def plist_startup; self.class.plist_startup end
 
   def build
     self.class.build
@@ -633,6 +636,7 @@ private
     end
 
     attr_rw :homepage, :keg_only_reason, :skip_clean_all, :cc_failures
+    attr_rw :plist_startup, :plist_manual
 
     Checksum::TYPES.each do |cksum|
       class_eval %Q{
@@ -717,6 +721,11 @@ private
       build.add name, description
     end
 
+    def plist_options options
+      @plist_startup = options[:startup]
+      @plist_manual = options[:manual]
+    end
+
     def conflicts_with formula, opts={}
       dependencies.add ConflictRequirement.new(formula, name, opts)
     end

Library/Homebrew/formula_installer.rb

@@ -160,7 +160,6 @@ class FormulaInstaller
     end
 
     keg = Keg.new(f.prefix)
-
     if keg.completion_installed? :bash
       ohai 'Caveats', <<-EOS.undent
         Bash completion has been installed to:
@@ -174,6 +173,45 @@ class FormulaInstaller
           #{HOMEBREW_PREFIX}/share/zsh/site-functions
         EOS
     end
+
+    if f.plist or keg.plist_installed?
+      if f.plist_startup and false
+        destination = '/Library/LaunchDaemons'
+      else
+        destination = '~/Library/LaunchAgents'
+      end
+
+      plist_filename = f.plist_path.basename
+      plist_link = "#{destination}/#{plist_filename}"
+      plist_domain = f.plist_path.basename('.plist')
+      launchctl_load = "launchctl load -w #{plist_link}"
+      destination_path = Pathname.new File.expand_path destination
+      plist_path = destination_path/plist_filename
+      s = []
+
+      # we readlink because this path probably doesn't exist since caveats
+      # occurs before the link step of installation
+      if not (plist_path).file? and not (plist_path).symlink?
+        s << "To have launchd start #{f.name} at login:"
+        s << "    mkdir -p #{destination}" unless destination_path.directory?
+        s << "    ln -sfv #{HOMEBREW_PREFIX}/opt/#{f.name}/*.plist #{destination}" #sudo
+        s << "Then to load #{f.name} now:"
+        s << "    #{launchctl_load}"
+        if f.plist_manual
+          s << "Or, if you don't want/need launchctl, you can just run:"
+          s << "    #{f.plist_manual}"
+        end
+      elsif Kernel.system "/bin/launchctl list #{plist_domain} &>/dev/null"
+        s << "You should reload #{f.name}:"
+        s << "    launchctl unload -w #{plist_link}"
+        s << "    #{launchctl_load}"
+      else
+        s << "To load #{f.name}:"
+        s << "    #{launchctl_load}"
+      end
+
+      ohai 'Caveats', s
+    end
   end
 
   def finish
@@ -288,13 +326,12 @@ class FormulaInstaller
   end
 
   def install_plist
-    if f.startup_plist
+    return unless f.plist
     # A plist may already exist if we are installing from a bottle
     f.plist_path.unlink if f.plist_path.exist?
-      f.plist_path.write f.startup_plist
+    f.plist_path.write f.plist
     f.plist_path.chmod 0644
   end
-  end
 
   def fix_install_names
     Keg.new(f.prefix).fix_install_names

Library/Homebrew/keg.rb

@@ -76,6 +76,12 @@ class Keg < Pathname
     dir.directory? and not dir.children.length.zero?
   end
 
+  def plist_installed?
+    Dir.chdir self do
+      not Dir.glob("*.plist").empty?
+    end
+  end
+
   def version
     require 'version'
     Version.new(basename.to_s)