/usr/lib/ruby/1.8/langscan/ is in liblangscan-ruby 1.2+cvs20070125-1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/ruby/1.8/langscan/_common.rb
/usr/lib/ruby/1.8/langscan/_easyscanner.rb
/usr/lib/ruby/1.8/langscan/_pairmatcher.rb
/usr/lib/ruby/1.8/langscan/_type.rb
/usr/lib/ruby/1.8/langscan/autoconf.rb
/usr/lib/ruby/1.8/langscan/automake.rb
/usr/lib/ruby/1.8/langscan/brainfuck.rb
/usr/lib/ruby/1.8/langscan/c.rb
/usr/lib/ruby/1.8/langscan/csharp.rb
/usr/lib/ruby/1.8/langscan/css.rb
/usr/lib/ruby/1.8/langscan/d.rb
/usr/lib/ruby/1.8/langscan/eiffel.rb
/usr/lib/ruby/1.8/langscan/elisp.rb
/usr/lib/ruby/1.8/langscan/io.rb
/usr/lib/ruby/1.8/langscan/java.rb
/usr/lib/ruby/1.8/langscan/javascript.rb
/usr/lib/ruby/1.8/langscan/lua.rb
/usr/lib/ruby/1.8/langscan/ocaml.rb
/usr/lib/ruby/1.8/langscan/perl/
/usr/lib/ruby/1.8/langscan/perl.rb
/usr/lib/ruby/1.8/langscan/perl/tokenizer.pl
/usr/lib/ruby/1.8/langscan/php.rb
/usr/lib/ruby/1.8/langscan/python.rb
/usr/lib/ruby/1.8/langscan/rpmspec.rb
/usr/lib/ruby/1.8/langscan/ruby/
/usr/lib/ruby/1.8/langscan/ruby.rb
/usr/lib/ruby/1.8/langscan/ruby/compat/
/usr/lib/ruby/1.8/langscan/ruby/compat/ripper/
/usr/lib/ruby/1.8/langscan/ruby/compat/ripper.rb
/usr/lib/ruby/1.8/langscan/ruby/compat/ripper/core.rb
/usr/lib/ruby/1.8/langscan/ruby/compat/ripper/filter.rb
/usr/lib/ruby/1.8/langscan/ruby/compat/ripper/lexer.rb
/usr/lib/ruby/1.8/langscan/ruby/compat/ripper/sexp.rb
/usr/lib/ruby/1.8/langscan/scheme.rb
/usr/lib/ruby/1.8/langscan/sh.rb
/usr/lib/ruby/1.8/langscan/text.rb