# Executing a command from a ruby script

**URL:** <https://www.ruby-forum.com/t/executing-a-command-from-a-ruby-script/112676>\
**Category:** Ruby\
**Created:** [August 22, 2007, 1:46am UTC](https://www.ruby-forum.com/t/executing-a-command-from-a-ruby-script/112676 "2007-08-22T01:46:11Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![greg](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/71c47a/32.png) [@greg](https://www.ruby-forum.com/u/greg)\
**Post date:** [August 22, 2007, 1:46am UTC](https://www.ruby-forum.com/t/executing-a-command-from-a-ruby-script/112676/1 "2007-08-22T01:46:11Z")

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Hi All,

I want to execute a command from a script e.g. var=`ls -l`, however I  
don’t want to specify the file until I have done some things in the  
ruby script, so I need something like var=`ls -l $file`. However, this  
is not working. Could anyone help me out. I would really appreciate  
it!

Thanks,  
Greg

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<div class="post-metadata">

**Author:** ![greg](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/71c47a/32.png) [@greg](https://www.ruby-forum.com/u/greg)\
**Post date:** [August 22, 2007, 1:49am UTC](https://www.ruby-forum.com/t/executing-a-command-from-a-ruby-script/112676/2 "2007-08-22T01:49:11Z")

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Hi,

Am Mittwoch, 22. Aug 2007, 08:44:59 +0900 schrieb greg:

> I need something like var=`ls -l $file`.

var=`ls -l #{file}`

Bertram

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**Author:** ![greg](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/71c47a/32.png) [@greg](https://www.ruby-forum.com/u/greg)\
**Post date:** [August 22, 2007, 1:56am UTC](https://www.ruby-forum.com/t/executing-a-command-from-a-ruby-script/112676/3 "2007-08-22T01:56:11Z")

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Works perfectly! You are awesome!

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<div class="post-metadata">

**Author:** ![greg](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/71c47a/32.png) [@greg](https://www.ruby-forum.com/u/greg)\
**Post date:** [August 22, 2007, 2:31am UTC](https://www.ruby-forum.com/t/executing-a-command-from-a-ruby-script/112676/4 "2007-08-22T02:31:13Z")

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Hi,

Am Mittwoch, 22. Aug 2007, 08:48:17 +0900 schrieb Bertram S.:

> Am Mittwoch, 22. Aug 2007, 08:44:59 +0900 schrieb greg:
> 
> > I need something like var=`ls -l $file`.
> 
> var=`ls -l #{file}`

Be aware of the security risk:

```
file = "; rm -rf *"
var=`ls -l #{file}`

```

Bertram

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**Author:** ![greg](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/71c47a/32.png) [@greg](https://www.ruby-forum.com/u/greg)\
**Post date:** [August 22, 2007, 2:23am UTC](https://www.ruby-forum.com/t/executing-a-command-from-a-ruby-script/112676/5 "2007-08-22T02:23:12Z")

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Hi,

Am Mittwoch, 22. Aug 2007, 08:54:58 +0900 schrieb greg:

> You are awesome!

Not me. Ruby is.

Bertram