From: Gennady <gfb@...>
Date: 2004-06-11T00:05:42+09:00
Subject: Re: Signals and threads

nobu.nokada@softhome.net wrote:
> Hi,
> 
> At Thu, 10 Jun 2004 16:37:02 +0900,
> Gennady Bystritsky wrote in [ruby-talk:103056]:
> 
>>sigquit_handler = trap "SIGQUIT", "IGNORE"
>>... <the code spawning a process (with popen) where I want SIGQUIT 
>>ignored>
>>trap "SIGQUIT", sigquit_handler
>>
>>I noticed that when the first trap returns nil, the second one does not 
>>restore a signal handler to "DEFAULT", as I would expect. I have to do 
>>something like that:
>>
>>trap "SIGQUIT", (sigquit_handler or "DEFAULT")
> 
> 
> Which version of ruby do you use?  It should return nil at the
> first.
> 
>   $ ruby18 -v -e 'p trap("SIGQUIT", nil)'
>   ruby 1.8.2 (2004-06-06) [i686-linux]
>   "DEFAULT"
> 
I use 1.6.8, and there trap returns nil if no handler is currently in 
use. I checked in 1.8.0 and it returns "DEFAULT", just as you mentioned. 
Thanks a lot. I will be gradually switching to 1.8.x.

Gennady.

[linux.gfbs:274]gfb> ruby -v -e 'p trap("SIGQUIT", "IGNORE")'
ruby 1.6.8 (2003-10-15) [i686-linux]
nil
[linux.gfbs:275]gfb> ruby8 -v -e 'p trap("SIGQUIT", "IGNORE")'
ruby 1.8.0 (2003-08-04) [i686-linux]
"DEFAULT"