ttytter: fix readline support

Closes Homebrew/homebrew#41835.

Formula/ttytter.rb

@@ -1,24 +1,37 @@
-require 'formula'
-
 class Ttytter < Formula
   desc "Twitter command-line client"
-  homepage 'http://www.floodgap.com/software/ttytter/'
-  url 'http://www.floodgap.com/software/ttytter/dist2/2.1.00.txt'
-  sha1 'a72b2c4b7da8a370ff15c7f5a1a3ecf9056590f0'
+  homepage "http://www.floodgap.com/software/ttytter/"
+  url "http://www.floodgap.com/software/ttytter/dist2/2.1.00.txt"
+  sha256 "86c6e7767c65e3179d4ed6368e27df5c4b200285207c3df3164c5a84a73517b1"
+
+  depends_on "readline" => :optional
+
+  resource "Term::ReadLine::TTYtter" do
+    url "https://cpan.metacpan.org/authors/id/C/CK/CKAISER/Term-ReadLine-TTYtter-1.4.tar.gz"
+    mirror "http://www.cpan.org/authors/id/C/CK/CKAISER/Term-ReadLine-TTYtter-1.4.tar.gz"
+    sha256 "ac373133cee1b2122a8273fe7b4244613d0eecefe88b668bd98fe71d1ec4ac93"
+  end
 
   def install
     bin.install "#{version}.txt" => "ttytter"
+
+    if build.with? "readline"
+      ENV.prepend_create_path "PERL5LIB", libexec/"lib/perl5"
+      resource("Term::ReadLine::TTYtter").stage do
+        system "perl", "Makefile.PL", "INSTALL_BASE=#{libexec}"
+        system "make"
+        system "make", "install"
+      end
+      bin.env_script_all_files(libexec/"bin", :PERL5LIB => ENV["PERL5LIB"])
+      chmod 0755, libexec/"bin/ttytter"
+    end
   end
 
-  def caveats; <<-EOS.undent
-    To take full advantage of readline features you must install readline:
-      brew install readline
-
-    and the Perl Module Term::ReadLine::TTYtter
-      cpan -i Term::ReadLine::TTYtter
-
-    Or if you have cpanminus:
-      cpanm Term::ReadLine::TTYtter
-    EOS
+  test do
+    IO.popen("#{bin}/ttytter", "r+") do |pipe|
+      assert_equal "-- using SSL for default URLs.", pipe.gets.chomp
+      pipe.puts "^C"
+      pipe.close_write
+    end
   end
 end