Modules should detect data errors and return an appropriate error value, but it is not their place to shut down the program. The author of the main routine has to decide whether to shut down, use some default value, or handle the problem some other way.

After all, if the program is running a nuclear reactor .....

--
TTTATCGGTCGTTATATAGATGTTTGCA

I'm not sure I understand your question. The most common way to print a message and exit is with die:

$date1 =~ /(\d\d)(\d\d)(\d\d)/
  or die "Invalid date format";
$time1 =~ /(\d\d):(\d\d)/
  or die "Invalid time format";
[download]

Or are you talking about catching the error from gmtime? You're doing that properly, and I don't believe there's a better way to do it. When I have code like this, I will often wrap the entire thing in an eval, like this:

eval {
    my $ref = shift;
    my $date1 = shift @$ref;
    my $time1 = shift @$ref;
    die unless $date1 =~ /(\d\d)(\d\d)(\d\d)/;
    my @date2 = ($1,$2,$3);
    die unless $time1 =~ /(\d\d):(\d\d)/;
    my @time2 = ($1,$2);
    my $t;
    $t = timegm(0,$time2[1],$time2[0],$date2[1],$date2[0]-1,$dat
+e2[2]+100)};
};
print "-1\n" and exit if $@;
[download]

I couldn't get your code and Time::Local to invalidate Feb. 31, 2003 08:40 by passing a ref to ('023103','08:40') so I whipped this up. As you can see, I choose to use die statements as opposed to the print and exit combo.

use Date::Calc qw(check_date check_time);

our $DEBUG = 1; # set to 0 to disable

print "woohoo!\n" if valid( ['033103','12:59'] ); # March 31, 2003 12:
+59 valid
print "w00t!\n" if valid( ['022803','13:00'] );      # February 28, 20
+03 13:00 valid
print "Yippee!\n" if valid( ['023103','08:40'] ); # February 31, 2003 
+8:40 invalid

sub valid {
    my $ref = shift;
    my $date = shift @$ref;
    my $time = shift @$ref;
    die "Invalid date format $date" unless $date =~ /(\d\d)(\d\d)(\d\d
+)/;
    my ($month, $day, $year) = ($1, $2, $3);
    $year += ($year <= 69) ? 2000 : 1900;
    die "Invalid date $date" unless (check_date($year,$month,$day));
    die "Invalid time format $time" unless $time =~ /(\d\d):(\d\d)/;
    my ($hour, $minute) = ($1, $2);
    die "Invalid time $time" unless (check_time($hour,$min,$sec));
    print "$date $time is valid.\n" if $DEBUG;
    return 1;
}
[download]

update: fixed $year update code

Or is there another way to catch the error?

As Time::Local calls croak() when a date is out of range, not really.

You could, of course, write a wrapper that would always call timegm() in an eval for you.

Or, if you aren't adverse to doing your own bounds checking or it isn't necessary, you could import the timegm_nocheck() function and use that instead.

-sauoq
"My two cents aren't worth a dime.";