# Using backticks ( \`cmd\`) hang child processes?

**URL:** <https://www.ruby-forum.com/t/using-backticks-cmd-hang-child-processes/118604>\
**Category:** Ruby\
**Created:** [October 29, 2007, 1:30pm UTC](https://www.ruby-forum.com/t/using-backticks-cmd-hang-child-processes/118604 "2007-10-29T13:30:48Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![noam](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/57b2e6/32.png) [@noam](https://www.ruby-forum.com/u/noam)\
**Post date:** [October 29, 2007, 1:30pm UTC](https://www.ruby-forum.com/t/using-backticks-cmd-hang-child-processes/118604/1 "2007-10-29T13:30:48Z")

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Hi All,

i execute small ruby code:

puts(“in x\n”)  
x = Thread.current  
y = Thread.start {  
i = 0;  
while (1)  
puts(“in y #{i}\n”)  
STDOUT.flush()  
i +=1;  
end  
puts(“in y1\n”)  
STDOUT.flush()

```
  }
 puts("in x1\n")
 STDOUT.flush()

```

# system(“sleep 5”)

```
 `sleep 5`

```

it seems that using `sleep 5` cause y thread to hang.  
if i change in and remark `sleep 5` and unmark system command , it seems  
to work just fine.

is it a bug?  
is this is the righr behavior?  
i’m using a little bit old version of ruby (1.8.2) but still, i didn’t  
find any post about this issue.

i’ll happy to hear any comment about this issue.

Thanks,  
Noam.

---

<div class="post-metadata">

**Author:** ![noam](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/57b2e6/32.png) [@noam](https://www.ruby-forum.com/u/noam)\
**Post date:** [October 29, 2007, 3:42pm UTC](https://www.ruby-forum.com/t/using-backticks-cmd-hang-child-processes/118604/2 "2007-10-29T15:42:20Z")

</div>

any one? something?

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<div class="post-metadata">

**Author:** ![noam](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/57b2e6/32.png) [@noam](https://www.ruby-forum.com/u/noam)\
**Post date:** [October 29, 2007, 5:19pm UTC](https://www.ruby-forum.com/t/using-backticks-cmd-hang-child-processes/118604/3 "2007-10-29T17:19:15Z")

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On Oct 29, 2007, at 6:30 AM, Noam Noam wrote:

> i’ll happy to hear any comment about this issue.

it’s all over the archives. probably you are windows and it’s a  
known issue. your option is to use systemu, for one.

are you on windows?

a @ [http://codeforpeople.com/](http://codeforpeople.com/)

---

<div class="post-metadata">

**Author:** ![noam](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/57b2e6/32.png) [@noam](https://www.ruby-forum.com/u/noam)\
**Post date:** [October 30, 2007, 5:39pm UTC](https://www.ruby-forum.com/t/using-backticks-cmd-hang-child-processes/118604/4 "2007-10-30T17:39:00Z")

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ara.t.howard wrote:

> On Oct 29, 2007, at 6:30 AM, Noam Noam wrote:
> 
> > > are you on windows?
> 
> a @ [http://codeforpeople.com/](http://codeforpeople.com/)

i’m using cygwin.  
where did you see this issue in the archives?  
Thanks

Noam