# Question about the system method

**URL:** <https://www.ruby-forum.com/t/question-about-the-system-method/154568>\
**Category:** Ruby\
**Created:** [December 1, 2008, 6:35pm UTC](https://www.ruby-forum.com/t/question-about-the-system-method/154568 "2008-12-01T18:35:55Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Jarod\_Z](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/e274bd/32.png) [@Jarod\_Z](https://www.ruby-forum.com/u/Jarod_Z)\
**Post date:** [December 1, 2008, 6:35pm UTC](https://www.ruby-forum.com/t/question-about-the-system-method/154568/1 "2008-12-01T18:35:55Z")

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Hi, all

```
 I want to use system method to run a background process, like

 system("ruby deamon.rb") # the deamon.rb runs a dead loop

 When my main process ends, I want to end the background process

```

too.

```
 How can I do it?

 If I can get the pid of background process, I can use

```

Process.kill. But the system method dosen’t return the pid.

```
 Does anyone here know the solution?

 Thank you

```

Jarod Z.

---

<div class="post-metadata">

**Author:** ![Jarod\_Z](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/e274bd/32.png) [@Jarod\_Z](https://www.ruby-forum.com/u/Jarod_Z)\
**Post date:** [December 1, 2008, 6:38pm UTC](https://www.ruby-forum.com/t/question-about-the-system-method/154568/2 "2008-12-01T18:38:57Z")

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On Mon, Dec 1, 2008 at 12:29 PM, Jarod Z. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
wrote:

> Hi, all
> 
> ```
> I want to use system method to run a background process, like
> 
> system("ruby deamon.rb") # the deamon.rb runs a dead loop
> 
> When my main process ends, I want to end the background process
> 
> ```
> 
> too.
> 
> ```
> How can I do it?
> 
> ```

The basic answer is to use IO.popen() - see  
[http://www.ruby-doc.org/core/classes/IO.html#M002267](http://www.ruby-doc.org/core/classes/IO.html#M002267)

For more advances applications you may want to take a look at Daemons:  
[http://daemons.rubyforge.org/](http://daemons.rubyforge.org/)

–  
Avdi

Home: [http://avdi.org](http://avdi.org)  
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---

<div class="post-metadata">

**Author:** ![Jarod\_Z](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/e274bd/32.png) [@Jarod\_Z](https://www.ruby-forum.com/u/Jarod_Z)\
**Post date:** [December 2, 2008, 2:45am UTC](https://www.ruby-forum.com/t/question-about-the-system-method/154568/3 "2008-12-02T02:45:40Z")

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IO.popen() works well.  
Thanks a lot!!

Jarod Z.