unlink: Use CLI::Parser to parse args

Library/Homebrew/cmd/unlink.rb

@@ -7,15 +7,35 @@
 #:    be unlinked, but will not actually unlink or delete any files.
 
 require "ostruct"
+require "cli_parser"
 
 module Homebrew
   module_function
 
+  def unlink_args
+    Homebrew::CLI::Parser.new do
+      usage_banner <<~EOS
+        `unlink` [<options>] <formula>
+
+        Remove symlinks for <formula> from the Homebrew prefix. This can be useful
+        for temporarily disabling a formula:
+        `brew unlink` <formula> `&&` <commands> `&& brew link` <formula>
+      EOS
+      switch "-n", "--dry-run",
+        description: "List all files which would be unlinked, but will  not actually unlink or "\
+                     "delete any files."
+      switch :verbose
+      switch :debug
+    end
+  end
+
   def unlink
-    raise KegUnspecifiedError if ARGV.named.empty?
+    unlink_args.parse
+
+    raise KegUnspecifiedError if args.remaining.empty?
 
     mode = OpenStruct.new
-    mode.dry_run = true if ARGV.dry_run?
+    mode.dry_run = true if args.dry_run?
 
     ARGV.kegs.each do |keg|
       if mode.dry_run
@@ -26,7 +46,7 @@ module Homebrew
 
       keg.lock do
         print "Unlinking #{keg}... "
-        puts if ARGV.verbose?
+        puts if args.verbose?
         puts "#{keg.unlink(mode)} symlinks removed"
       end
     end