If an operation dies, all the open handles are closed as part of the normal shutdown. Also, with modern perl, you can use a lexical scalar (my $foo;) and the $foo handle will be closed automatically when it goes out of scope.

It is good policy to check all interaction with the os for errors and die, retry, or otherwise handle the error.

Your nest of conditionals is unnecessarily complicated, therefore. I'd rewrite it something like this: 

{
    sysopen my $trigger,
            $config->{xmlpath}.'trigfile.tf',
            O_WRONLY | O_EXCL | O_CREAT
        or die $!;
    flock $trigger, LOCK_EX | LOCK_NB or die $!;
    print $trigger $/ or die $!;
    close $trigger or die $!;
}

[download]
At any stage that dies, the file is closed. if you want to continue in spite of errors, you can replace the die clause with warn $! and last; which will have the same effect on the handle, give the same error message, but will continue at the end of the block. I didn't try to duplicate your html output for errors, but it can be inserted in the error message and CGI::Carp can send the errors to the browser.

After Compline,
Zaxo

In reply to Re: Flock, die and statement order by Zaxo
in thread Flock, die and statement order by Ionizor

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