From: brabuhr@...
Date: 2011-02-10T21:22:40+09:00
Subject: Re: System calls with ` in parameters

On Wed, Feb 9, 2011 at 6:48 PM, Gerad S. <geradstemke@gmail.com> wrote:
> Because of this, the syntax of:
>
> `echo "#{someVar}" | ./some-script.py > "#{outputFile}"`
>
> is breaking when #{someVar} contains the tick `.  This causes the
> command to fail because it executes up to the tick ` in someVar and not
> to the end as intended.
>
> I have also tried using the system() command as follows:
>
> system("echo \"#{someVar}\" | ./some-script.py > \"#{outputFile}\"")
>
> But this fails when there is a tick ` in #{someVar} as well.

Could you show us a working example of the problem?

>> s = "foo `date` baz"
=> "foo `date` baz"

>> system "echo #{s}"
foo Thu Feb 10 07:18:23 EST 2011 baz
=> true

>> system "echo \"#{s}\""
foo Thu Feb 10 07:18:32 EST 2011 baz
=> true

>> system "echo '#{s}'"
foo `date` baz
=> true

>> require 'shellwords'
=> true
>> `echo #{Shellwords.escape(s)}`
=> "foo `date` baz\n"