# Auto Selecting ports

**URL:** <https://www.ruby-forum.com/t/auto-selecting-ports/83766>\
**Category:** Ruby\
**Created:** [March 19, 2006, 1:35am UTC](https://www.ruby-forum.com/t/auto-selecting-ports/83766 "2006-03-19T01:35:31Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![aaronpowell](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/7bcc69/32.png) [@aaronpowell](https://www.ruby-forum.com/u/aaronpowell)\
**Post date:** [March 19, 2006, 1:35am UTC](https://www.ruby-forum.com/t/auto-selecting-ports/83766/1 "2006-03-19T01:35:31Z")

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Hi, I’m trying to start up a WEBrick server on an unused port on my  
system. On linux, I just tell it to use port 0, and I’m assigned an  
open port. This doesn’t work on OS X for some reason. Does anyone have  
a better way to do this? Here’s my test code:

require ‘webrick’

server = WEBrick::HTTPServer.new(  
:Port =\> 0,  
:DocumentRoot =\> Dir::pwd + “/htdocs”  
)

puts “Using port: #{server[:Port]}”

trap(“INT”) { server.stop }  
server.start

On linux, I get this:

[2006-03-18 15:56:25] INFO WEBrick 1.3.1  
[2006-03-18 15:56:25] INFO ruby 1.8.4 (2005-12-24) [i386-linux]  
Using port: 33278  
[2006-03-18 15:56:25] INFO WEBrick::HTTPServer#start: pid=22031  
port=33278

And I can connect to that port. On OS X, I get this:

[2006-03-18 15:56:21] INFO WEBrick 1.3.1  
[2006-03-18 15:56:21] INFO ruby 1.8.2 (2004-12-25) [powerpc-darwin8.0]  
Using port: 0  
[2006-03-18 15:56:21] INFO WEBrick::HTTPServer#start: pid=14353 port=0

And I cannot connect to port 0. Does anyone have any suggestions for  
me? I would appreciate any help I can get. Thanks!

–Aaron