[ruby-talk:5409] Re: Path for requires statements

"Chris Morris" <[e-mail]> writes:

> Newbie alert: ruby can't find the file I'm referring to in a require
> statement. The file required is in the same directory as the original source
> file. Obviously, this doesn't work. Where does ruby get its path info?

The default path to search is set when Ruby is installed, and includes 
all the standard Ruby directories, along with the current
directory. You can get a list by printing out the $: array:

     puts $:
  =>
     /tc/usr/lib/ruby/site_ruby/1.6/i686-linux
     /tc/usr/lib/ruby/site_ruby/1.6
     /tc/usr/lib/ruby/site_ruby
     /tc/usr/lib/ruby/1.6/i686-linux
     /tc/usr/lib/ruby/1.6
     .

You can modify this at runtime using the -I option, and the RUBYLIB
environment variable:

     RUBYLIB=wombat:koala  ruby -Iwallaby -e 'puts $:'
   =>
     wallaby
     wombat
     koala
     /tc/usr/lib/ruby/site_ruby/1.6/i686-linux
     /tc/usr/lib/ruby/site_ruby/1.6
     /tc/usr/lib/ruby/site_ruby
     /tc/usr/lib/ruby/1.6/i686-linux
     /tc/usr/lib/ruby/1.6
     .

However, if you run a script out of a directory that isn't your
current working directory, and that script tries to require a file in
its own directory, it won't find it unless that directory also happens 
to be in the path.

     dave[~ 22:45:42] cd tmp
     dave[~/tmp 22:47:01] cat >a.rb
     require 'b.rb'
     dave[~/tmp 22:47:09] cat >b.rb
     puts "hello"
     dave[~/tmp 22:47:41] ruby a.rb
     hello
     dave[~/tmp 22:47:43] cd ..
     dave[~ 22:47:44] ruby tmp/a.rb
     tmp/a.rb:1:in `require': No such file to load -- b.rb (LoadError)
             from tmp/a.rb:1
     dave[~ 22:47:48]


Regards


Dave