bin/bagit in bagit-0.3.2 vs bin/bagit in bagit-0.3.4

@@ -1,10 +1,13 @@
 #!/usr/bin/env ruby
 
 require 'bagit'
 require 'docopt'
+require 'logger'
 
+logger = Logger.new(STDOUT)
+
 doc = <<DOCOPT
 BagIt.
 
 Usage: 
   bagit add [-f <file>...] [-t <tagfile>...] BAGPATH
@@ -35,21 +38,27 @@
   #             [--internal-sender-identifier <sender-id>] [--internal-sender-description <sender-desc>] 
   #             [--bag-info-entry <label> <value>] [-f <file>...] [-t <tagfile>...] BAGPATH
 
 begin
   opts = Docopt::docopt(doc, version: BagIt::VERSION)
-  
-  bag = BagIt::Bag.new(opts['BAGPATH'])
 
+  unless opts['validate']
+    bag = BagIt::Bag.new(opts['BAGPATH'])
+  end
   #####################################
   # commands that don't alter the bag #
   #####################################
   if opts['validate']
-    if opts['--oxum']
-      puts bag.valid_oxum?.to_s
+    if File.exists?(opts['BAGPATH']+'/bag-info.txt') && File.directory?(opts['BAGPATH']+'/data') && File.exists?(opts['BAGPATH']+'/manifest-md5.txt') || File.exists?(opts['BAGPATH']+'/manifest-sha1.txt')
+      bag = BagIt::Bag.new(opts['BAGPATH'])
+      if opts['--oxum']
+        logger.info(bag.valid_oxum?.to_s)
+      else
+        logger.info(bag.valid?.to_s)
+      end
     else
-      puts bag.valid?.to_s
+      logger.error("Not a valid bag")
     end
     # validation commands MUST NOT change manifest or bag-info files
     exit
   end
 
@@ -81,11 +90,11 @@
           bag.add_file(File.basename(datafile), datafile)
         elsif opts['delete']
           bag.remove_file(File.basename(datafile))
         end
       rescue Exception => e
-        puts "Failed operation on bag file: #{e.message}"
+        logger.error("Failed operation on bag file: #{e.message}")
       end
     }  
   end
 
   # handle adding tag files
@@ -105,19 +114,19 @@
           bag.delete_tag_file(File.basename(tagfile))
         elsif opts['remove']
           bag.remove_tag_file(File.basename(tagfile))
         end
       rescue Exception => e
-        puts "Failed operation on tag file: #{e.message}"
+        logger.error("Failed operation on tag file: #{e.message}".red)
       end
     }
   end
 
   # if we haven't quit yet, we need to re-manifest
   # only do tags if tag files have been explictly added/removed or it is explictly called 
   bag.tagmanifest! if opts['-T'] or not opts['-t'].nil?
   bag.manifest!
 
 rescue Docopt::Exit => e
-  puts e.message
+  logger.error(e.message.red)
 end