# How to know the OS platform

**URL:** <https://www.ruby-forum.com/t/how-to-know-the-os-platform/105041>\
**Category:** Ruby\
**Created:** [May 25, 2007, 7:20am UTC](https://www.ruby-forum.com/t/how-to-know-the-os-platform/105041 "2007-05-25T07:20:05Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![huang\_zhimin](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/54ee81/32.png) [@huang\_zhimin](https://www.ruby-forum.com/u/huang_zhimin)\
**Post date:** [May 25, 2007, 7:20am UTC](https://www.ruby-forum.com/t/how-to-know-the-os-platform/105041/1 "2007-05-25T07:20:05Z")

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How can i know which OS platform the ruby application is running, MS  
Windows, Mac OS or Linux?

thank you

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**Author:** ![huang\_zhimin](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/54ee81/32.png) [@huang\_zhimin](https://www.ruby-forum.com/u/huang_zhimin)\
**Post date:** [May 25, 2007, 7:50am UTC](https://www.ruby-forum.com/t/how-to-know-the-os-platform/105041/2 "2007-05-25T07:50:08Z")

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On 5/25/07, huang zhimin [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> How can i know which OS platform the ruby application is running, MS  
> Windows, Mac OS or Linux?
> 
> thank you
> 
> –  
> [CodeLineStatistics download | SourceForge.net](http://sourceforge.net/projects/mycodeline/)

I’ve never used this, but does this help?

[http://www.rubycentral.com/book/rubyworld.html#S5](http://www.rubycentral.com/book/rubyworld.html#S5)

Harry

–

A Look into Japanese Ruby List in English  
[http://www.kakueki.com/](http://www.kakueki.com/)

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**Author:** ![huang\_zhimin](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/54ee81/32.png) [@huang\_zhimin](https://www.ruby-forum.com/u/huang_zhimin)\
**Post date:** [May 25, 2007, 8:25am UTC](https://www.ruby-forum.com/t/how-to-know-the-os-platform/105041/3 "2007-05-25T08:25:40Z")

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huang zhimin wrote:

> How can i know which OS platform the ruby application is running, MS  
> Windows, Mac OS or Linux?
> 
> thank you

$ irb

> > puts PLATFORM  
> > x86\_64-linux  
> > =\> nil
> 
> >