flex.rb

class Flex < Formula
  desc "Fast Lexical Analyzer, generates Scanners (tokenizers)"
  homepage "http://flex.sourceforge.net"
  url "https://ftp.gnu.org/old-gnu/gnu-0.2/src/flex-2.5.4.tar.gz"
  sha1 "308b912c41f68504f1256e57218bde266fc07c57"

  keg_only :provided_by_osx, "Some formulae require a newer version of flex."

  depends_on "gettext"

  def install
    system "./configure", "--disable-dependency-tracking",
                          "--disable-shared",
                          "--prefix=#{prefix}"
    system "make", "install"
  end

  test do
    (testpath/"test.flex").write <<-EOS.undent
      CHAR   [a-z][A-Z]
      %%
      {CHAR}+      printf("%s", yytext);
      [ \\t\\n]+   printf("\\n");
      %%
      int main()
      {
        yyin = stdin;
        yylex();
      }
    EOS
    system "#{bin}/flex", "test.flex"
    system ENV.cc, "lex.yy.c", "-L#{lib}", "-lfl", "-o", "test"
    assert_equal shell_output("echo \"Hello World\" | ./test"), <<-EOS.undent
      Hello
      World
    EOS
  end
end