From: Brian Candler <B.Candler@...>
Date: 2003-08-07T06:56:50+09:00
Subject: Re: $: - where does it get its initial values?

On Thu, Aug 07, 2003 at 05:23:35AM +0900, Tuan Bui wrote:
> Where does $: get its values from?  The book says that it contains an 
> array of places to search for loaded files and that it is "initialized 
> to the list of standard directories, plus any additional ones you 
> specify using RUBYLIB and -I."  Where does ruby get these standard 
> directories?

In ruby.c, look for rb_load_path and calls to ruby_incpush; it is set from a
series of compile-time constants and/or environmnet variables.

    if (rb_safe_level() == 0) {
        ruby_incpush(getenv("RUBYLIB"));
    }

#ifdef RUBY_SEARCH_PATH
    ruby_incpush(RUBY_RELATIVE(RUBY_SEARCH_PATH));
#endif

    ruby_incpush(RUBY_RELATIVE(RUBY_SITE_LIB2));
#ifdef RUBY_SITE_THIN_ARCHLIB
    ruby_incpush(RUBY_RELATIVE(RUBY_SITE_THIN_ARCHLIB));
#endif
    ruby_incpush(RUBY_RELATIVE(RUBY_SITE_ARCHLIB));
    ruby_incpush(RUBY_RELATIVE(RUBY_SITE_LIB));

    ruby_incpush(RUBY_RELATIVE(RUBY_LIB));
#ifdef RUBY_THIN_ARCHLIB
    ruby_incpush(RUBY_RELATIVE(RUBY_THIN_ARCHLIB));
#endif
    ruby_incpush(RUBY_RELATIVE(RUBY_ARCHLIB));

    if (rb_safe_level() == 0) {
        ruby_incpush(".");
    }