Re: Fix kill(0, $pid) on Windows

Jan Dubois wrote:
> On Tue, 17 Apr 2007, youshi10u.washington.edu wrote:
>> Try this:
>>
>> perl -e 'kill 15, undef; print "Hello, cruel
world!";'
>>
>> And yes, I was the person that originally sent the
bug report. If
>> someone could provide me with the POSIX spec that
says that an
>> undefined value equals 0, and a 0 value with kill
works out to kill
>> the calling process, I'd appreciate it.
> 
> From `perldoc -f kill`:
> 
>     kill SIGNAL, LIST
>             Sends a signal to a list of processes.
Returns the number of
>             processes successfully signaled (which is
not necessarily the
>             same as the number actually killed).
> 
> Processes are identified by PID, which is a number.
`perldoc perlsyn`
> says this:
> 
>                                          When used as a
number, "undef" is
>     treated as 0; when used as a string, it is treated
as the empty string,
> 
> This means that kill(15, undef) should be treated the
same as kill(15, 0)
> due to Perl data transformation rules.
> 
> POSIX (http://www.opengroup.org/onlinepubs/009695399/f
unctions/kill.html) 
> says this about using a PID of 0:
> 
>     If pid is 0, sig shall be sent to all processes
(excluding an
>     unspecified set of system processes) whose process
group ID is equal
>     to the process group ID of the sender, and for
which the process has
>     permission to send a signal.
> 
> Therefore `kill(15, undef)` should send signal 15 to
all processes in
> the current process group, including the process
issuing the kill()
> call itself.
> 
> Cheers,
> -Jan

Jan,
	Could someone maybe write that as a gotcha in the perldoc?
It seems to 
be a bit more encompassing, knowledgewise, to realize that,
and it also 
seems like it could bite some devs in the proverbial rear if
they didn't 
know that.

	Thanks though for the lesson .
-Garrett