irb: require returns false?

[Mike Carbs]

hey everyone (ruby n00b here),

I am trying to compile ruby 1.8.6-p287. I built it using:

/configure --prefix=/usr/local/ruby --enable-pthread --enable-shared

I was playing with how support for things like iconv, gdbm, openssl, etc
worked and did:

irb(main):001:0> require 'gdbm'
LoadError: no such file to load -- gdbm
from (irb):1:in `require'
from (irb):1

so I installed the gdbm devel libs, and did recompiled. Now I get:

irb(main):004:0> require 'gdbm'
=> false

When I use Redhats stock 1.8.5 rpm, I get:

irb(main):001:0> require 'gdbm'
=> true

So my question is... what does "false" mean? The first time I tried, it
complained about not being able to load the file. After installing the
devel package, it now just says false. Does this mean that it properly
loading it but just not enabling it somehow?

Can someone shed some light on this for me?

Thanks!

 

[Jakub Pavlík jn.]

When require returns false it means that the library has already been required.
(At least I don't know any other case...)