I was looking at the Non-buffered read from program thread and thinking that using an eval block and alarm would work. However, when the alarm triggers any output from the command is lost. Is there a way to catch the output regardless? I assume this has something to do with signal handling?

eval.pl:

#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;

my @return;
eval {
    local $SIG{ALRM} = sub { die "alarm\n" }; # NB: \n required
    alarm 5;
    @return = `./test.pl`;
    alarm 0;
};

if( $@ ) {   # CASE: Command timed out
    die unless $@ eq "alarm\n";   # propagate unexpected errors
}
else {       # CASE: Did *not* timeout
}

print Data::Dumper->Dump([\@return],['return']);
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test.pl

#!/usr/bin/perl
print "Foo\n";
sleep 2;
print "Bar\n";
sleep 3;
print "Foobar\n";
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output

$return = [];
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