Re^2: Executing Systems Calls with Care

in reply to Re: Executing Systems Calls with Care
in thread Executing Systems Calls with Care

UPDATE: I modified this post because I thought noone had answered it and I thought better of my question after testing. In the interest of keeping following posts On Topic, this sub_question was initially,
"Will it work if you substitute &some_subroutine; instead of die?" in the section local $SIG{ALRM} = sub { die "alarm\n" };
CURRENT QUESTION:

     local $SIG{ALRM} = sub { die "alarm\n" };
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I can replace the die "alarm\n" section here with a subroutine with no problems (actually tested it ;->)

but this brings up something else that I don't understand.. What causes the above example to enter the

if ($@) 
    {
    die unless $@ eq "alarm\n";   # propagate unexpected errors
    # handle the timed out operation
    }
[download]

section?

-Kevin

my $a='62696c6c77667269656e6440676d61696c2e636f6d';
while ($a=~m/(^.{2})/s)
{print unpack('A',pack('H*',"$1"));$a=~s/^.{2}//s;}
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Re^3: Executing Systems Calls with Care by matija (Priest) on Feb 15, 2005 at 09:23 UTC
Will it work if you substitute `&some_subroutine;` instead of die? Well, in principle, sure. But make sure that he `some_subroutine` realizes that there may be error conditions it can't handle, and dies if it encounters a situation it isn't explicitly designed to handle. You need to be defensive when you're designing this subroutine. Defensive and paranoid.	[reply] [d/l] [select]
Re^3: Executing Systems Calls with Care by phaylon (Curate) on Feb 15, 2005 at 12:05 UTC
As 'perldoc -f eval' says: If the code to be executed doesn't vary, you may use the eval-BLOCK form to trap run-time errors without incurring the penalty of recompiling each time. The error, if any, is still returned in $@. Ordinary morality is for ordinary people. -- Aleister Crowley	[reply]

In Section Seekers of Perl Wisdom