# Require 101 **URL:** \ **Category:** Ruby\ **Created:** [January 5, 2006, 10:27pm UTC](https://www.ruby-forum.com/t/require-101/94480 "2006-01-05T22:27:45Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![brian](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/97f17d/32.png) [@brian](https://www.ruby-forum.com/u/brian)\ **Post date:** [January 5, 2006, 10:27pm UTC](https://www.ruby-forum.com/t/require-101/94480/1 "2006-01-05T22:27:45Z")
Hello all, What does the return value of a require statement supposed to indicate? My understanding was that ‘true’ meant the required library got properly loaded. When I open a new IRB session and type, say, “require ‘builder’” I get a false returned. require ‘builder’’ =\> false However, it appears that the statement does in fact load the library (the new classes in the library become available, etc). Why is the statement returning false (or how can I diagnose why) and is it something to be concerned over? —Brian ---
**Author:** ![brian](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/97f17d/32.png) [@brian](https://www.ruby-forum.com/u/brian)\ **Post date:** [January 5, 2006, 10:42pm UTC](https://www.ruby-forum.com/t/require-101/94480/2 "2006-01-05T22:42:49Z")
Brian B. wrote: > require ‘builder’’ > =\> false > > However, it appears that the statement does in fact load the library > (the > new classes in the library become available, etc). Why is the statement > returning false (or how can I diagnose why) and is it something to be > concerned over? A false return means the file was already in $", and so wasn’t loaded again. I’m guessing that some earlier require’d file has already brought in builder.rb If the file can’t be found, and exception is raised. ---
**Author:** ![brian](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/97f17d/32.png) [@brian](https://www.ruby-forum.com/u/brian)\ **Post date:** [January 5, 2006, 10:55pm UTC](https://www.ruby-forum.com/t/require-101/94480/3 "2006-01-05T22:55:06Z")
Brian B. wrote: > Hello all, > > What does the return value of a require statement supposed to indicate? > My > understanding was that ‘true’ meant the required library got properly > loaded. > > When I open a new IRB session and type, say, “require ‘builder’” I get a > false returned. > > require ‘builder’’ > =\> false > > However, it appears that the statement does in fact load the library > (the > new classes in the library become available, etc). Why is the statement > returning false (or how can I diagnose why) and is it something to be > concerned over? Because Builder has that stupid autorequire attribute set in its gem spec. When you require builder, RubyGems determines that builder isn’t in your list of available libraries, so it activates the gem and automatically requires the file listed in the autorequire attribute (which happens to be builder). Then RubyGems allows your original require to take place, which requires the builder file again. But, since builder was already autorequired, this time it returns a false. Yes, this is a bug. Yes, it is fixed in the CVS head of RubyGems. This is one of the (many) reasons I now believe autorequire was a mistake. I should email the author of builder and encourage him to remove the autorequire in the gem spec. Wait, oh, nevermind. – – Jim W. ---
**Author:** ![brian](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/97f17d/32.png) [@brian](https://www.ruby-forum.com/u/brian)\ **Post date:** [January 5, 2006, 11:00pm UTC](https://www.ruby-forum.com/t/require-101/94480/4 "2006-01-05T23:00:50Z")
> A false return means the file was already in $", and so wasn’t loaded > again. I’m guessing that some earlier require’d file has already brought > in builder.rb This theory does not square with the fact that the require line does seem to load a previously unloaded library. > Builder::XmlMarkup.new # fails with a NameError > require ‘builder’ #returns false > Builder::XmlMarkup.new # now if works Brian ---
**Author:** ![brian](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/97f17d/32.png) [@brian](https://www.ruby-forum.com/u/brian)\ **Post date:** [January 6, 2006, 12:18am UTC](https://www.ruby-forum.com/t/require-101/94480/5 "2006-01-06T00:18:58Z")
> Because Builder has that stupid autorequire attribute set in its gem > spec. Thank you for the explanation. I stumbled across this with builder while walking through an article about builder ([Creating XML with Ruby and Builder](http://www.xml.com/pub/a/2006/01/04/creating-xml-with-ruby-and-builder.html) ) but I seem to often enough encounter what seem to be invalid ‘false’ returns when requiring other libraries. Is this autocomplete problem a problem with quite a few other gems? And does it spread easily because any require which includes a require with that bug will also be returning false? If so it sounds like the long and the short of it for us users of gems is we can often (and maybe even generally should) ignor the return value of require because it gives so many false positives. Fair statement or overstating the bug? Brian ---
**Author:** ![brian](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/97f17d/32.png) [@brian](https://www.ruby-forum.com/u/brian)\ **Post date:** [January 5, 2006, 11:06pm UTC](https://www.ruby-forum.com/t/require-101/94480/6 "2006-01-05T23:06:51Z")
Brian B. wrote: > seem to > load a previously unloaded library. Sorry. I failed to consider that RubyGems was possibly coming into play here. ---
**Author:** ![brian](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/97f17d/32.png) [@brian](https://www.ruby-forum.com/u/brian)\ **Post date:** [January 6, 2006, 1:01am UTC](https://www.ruby-forum.com/t/require-101/94480/7 "2006-01-06T01:01:05Z")
On Jan 5, 2006, at 3:18 PM, Brian B. wrote: > returns when requiring other libraries. Is this autocomplete > or overstating the bug? > > Brian Yes for the short answer. I have found that usually if it returns fals then things are ok. If it errors out with an exception then its not ok. Cheers- -Ezra