From: Chuck Remes <cremes.devlist@...>
Date: 2010-08-31T02:29:27+09:00
Subject: Re: fork() function is unimplemented on this machine


On Aug 30, 2010, at 11:47 AM, Ralph Shnelvar wrote:

> I am trying to implement the code on page 181 of *Programming Ruby 1.9*
> 
> The code on that page reads
> 
> - - -
> trap("CLD") do
>  pid = Process.wait
>  puts "Child pid #{pid}: terminated
> end
> fork { exec("sort testfile >output.txt") }
> - - -
> 
> 
> When I attempt to run similar code I first get that
>  unsupported signal SIGCLD
> 
> I tried SIGCHLD ... same problem.
> 
> Signals.list generates
>  {"SEGV"=>11, "KILL"=>9, "TERM"=>15, "INT"=>2, "FPE"=>8, "ABRT"=>22, "ILL"=>4, "EXIT"=>0}
> 
> So I next tried 
> 
> - - -
> trap("EXIT") do
>  pid = Process.wait
>  puts "Child pid #{pid}: terminated
> end
> fork { exec("sort testfile >output.txt") }
> - - -
> 
> and that's when I get the msg 
>  fork() function is unimplemented on this machine
> 
> 
> 
> Is fork truly not implemented for 1.8.6 and Windows?

As far as I know, Windows does not support fork.

> How can I execute (spawn) an external program in 1.8.6 and know when the program is finished?

For one, upgrade to Ruby 1.9.1 or 1.9.2 at minimum. After doing so, check out Kernel#spawn.

http://ruby-doc.org/ruby-1.9/classes/Kernel.src/M002642.html

This code is supported under Windows.

> here are the various signals for ruby documented?

I don't know.

cr