Comments on: Tip: Running command line / shell commands in Ruby using %x

By: Tony Mann

Tony Mann — Thu, 09 Dec 2010 02:01:30 +0000

Example #2 is not right. It should be:

@whois = %x[whois #{dom}]

That is, no backslashes. If you backslash, then you are asking the shell to do the interpolation instead of Ruby.

By: margaret

margaret — Thu, 10 Jul 2008 16:58:03 +0000

I prove the three options but i’m get the follow error: Errno::ECONNREFUSED in … What i am doing bad?? i prove exec command too and the server shut down after execute the command.

Tanks

By: gaw.in

gaw.in — Thu, 05 Jun 2008 08:41:25 +0000

# Steve: you could start a thread and retrieve the result later.

dom = ‘clockobj.co.uk’
t = Thread.new { `whois #{dom}` }
puts “Proceed with your code…”
puts t.value

By: steve

steve — Tue, 25 Dec 2007 15:54:49 +0000

I’m kind of a newbe, but do these operations wait for the command line/shell command to complete, ie as if you were calling the function from a shell or command line and the whois operation was complete, to return to the ruby app and execute the next line of code? Maybe this is obvious, but I haven’t seen said details specified. Thanks either way for the %x[], very helpfull

By: Jon

Jon — Thu, 01 Nov 2007 14:53:38 +0000

Thanks for the comment, indeed this also works in exactly the same way. Interesting enough the syntax highlighting in RadRails doesn’t like %x[] so if you are using this, you may prefer the back tick approach i.e. @whois = `whois #{dom}`

By: Ikai

Ikai — Thu, 01 Nov 2007 14:52:54 +0000

Hey there, Thought I’d let you know there are a few different ways – I didn’t know about %x, but it is very similar to the backtick (`). Example: `dig yahoo.com` `dig #{domain}` Double quote rules apply. Of course, I might start adopting the %x[] format for readability – unless you are using an IDE or VIM (my choice) with syntax highlighting, backticks are hard to spot.