# RbConfig::CONFIG\['CPP'\] question

**URL:** <https://www.ruby-forum.com/t/rbconfig-config-cpp-question/191578>\
**Category:** Ruby\
**Created:** [July 14, 2010, 7:10pm UTC](https://www.ruby-forum.com/t/rbconfig-config-cpp-question/191578 "2010-07-14T19:10:41Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![rogerdpack](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/45deac/32.png) [@rogerdpack](https://www.ruby-forum.com/u/rogerdpack)\
**Post date:** [July 14, 2010, 7:10pm UTC](https://www.ruby-forum.com/t/rbconfig-config-cpp-question/191578/1 "2010-07-14T19:10:41Z")

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Currently we have this:

> > require ‘rbconfig’  
> > RbConfig::CONFIG[‘CC’]  
> > =\> “gcc”
> 
> > RbConfig::CONFIG[‘CPP’]  
> > =\> “gcc -E”

The first one I understand–it’s the C compiler. The second one I don’t  
though-- “-E” just means to run only the pre-processor. Is that right?  
-r

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**Author:** ![rogerdpack](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/45deac/32.png) [@rogerdpack](https://www.ruby-forum.com/u/rogerdpack)\
**Post date:** [July 14, 2010, 7:54pm UTC](https://www.ruby-forum.com/t/rbconfig-config-cpp-question/191578/2 "2010-07-14T19:54:08Z")

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On Jul 14, 2010, at 1:10 PM, Roger P. wrote:

> though-- “-E” just means to run only the pre-processor. Is that  
> right?  
> -r

CPP =\> C Pre-Processor  
^ ^ ^

Yes!

-Rob

Rob B.  
removed\_email\_address@domain.invalid [http://AgileConsultingLLC.com/](http://AgileConsultingLLC.com/)  
removed\_email\_address@domain.invalid [http://GaslightSoftware.com/](http://GaslightSoftware.com/)

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<div class="post-metadata">

**Author:** ![rogerdpack](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/45deac/32.png) [@rogerdpack](https://www.ruby-forum.com/u/rogerdpack)\
**Post date:** [July 14, 2010, 7:55pm UTC](https://www.ruby-forum.com/t/rbconfig-config-cpp-question/191578/3 "2010-07-14T19:55:44Z")

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> CPP =\> C Pre-Processor  
> ^ ^ ^
> 
> Yes!

Thanks.