use warnings;
use strict;

my $ok = eval {
    blah() or die "damn thing failed!";
    1;
};

if ($ok){
    print "success\n";
}
else {
    print "failed, doing something else\n";
}

sub blah {
    # simulate a fail
    return 0;
}

##</code><code>##

eval { blah() or die "failed"; };

if ($@){
    ...
}

##</code><code>##

if ($@ =~ /timeout/){
    ...
}