Hi t0m,
I wouldn't really call this a Catalyst bug. It's more some sort of Perl
behavior that I did know of / expect. My Catalyst code is along these
lines (and runs on a Linux 2.6 kernel):
sub catalyst_run_app {
my $original_sig_chld = $SIG{CHLD}; # system calls always return
-1 ("No child processes"), even when the call is sucessful
$SIG{CHLD} = 'DEFAULT'; # system calls will return 0 for success
(-1 is a failure)
use 'App';
eval {
&App::main(); # This function contains a system() call
};
$SIG{CHLD} = $original_sig_chld; # restore original sig chld value
if ($@) { # check for execution errors
# warn that there was an execution error
}
# Display results
}
There's some more info about this at:
http://www.schwer.us/journal/2008/02/06/perl-sigchld-ignore-system-and-you/
I must say that I don't fully appreciate the differences between the
different child signal methods. I'm happy with using 'DEFAULT'.
The easiest way to reproduce this behavior is to run these commands:
perl -e '$SIG{CHLD} = 'IGNORE'; print system('echo')."\n";'
Returns:
-1
Whereas:
perl -e '$SIG{CHLD} = 'DEFAULT'; print system('echo')."\n";'
Returns:
0
I'm not sure what you mean with using $class->handle_request; in
Catalyst/Engine/HTTP.pm. My Catayst app runs using the Catalyst test
server at the moment. I haven't deployed it on a standalone webserver yet.
Cheers,
Florent
Tomas Doran wrote:
On 19 Dec 2008, at 16:21, Florent Angly wrote:
Well, after some more fiddling and researching, I figured this
problem out.
Using the modified command:
system(@formatdb_cmd) == 0 or die("Could not run command:
@formatdb_cmd\nReturn status: $?\nMessage: $!");
I found out that my error message is:
No child processes
It turns out that in Catalyst, $SIG{CHLD} = 'IGNORE'. Setting
$SIG{CHLD} to 'DEFAULT' makes the system() calls return the proper
status.
I assume that you do this like this:
{
local $SIG{CHLD} = 'DEFAULT';
system('my system command');
}
Does doing something similar around $class->handle_request; in
Catalyst/Engine/HTTP.pm make it work in a generic way so that you
don't have to do this hack locally?
And is there any chance you could write a simple test which shows the
return values being lost, so that we can properly fix this in
Catalyst, with appropriate regression testing?
Cheers
t0m
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