sprintf(), Time::Local and Date::Calc

japhy — Tue, 17 Oct 2000 21:19:15 +0000

If you want to do simple string formatting, use the sprintf() and printf() functions (borrowed from C, of course):

($day,$mon,$year) = (3,4,1982);
$date = sprintf "%02d/%02d/%4d", $mon, $day, $year;
print $date;  # 04/03/1982

Read perldoc -f sprintf and perldoc -f printf for information on those functions.

For date calculations, you should be safe in using the Time::Local module (it comes with Perl):

use Time::Local;
$now = '10/17/2000';
$plus_days = 500;
$future = add_days($now,$plus_days);
 
sub add_days {
  my ($date,$days) = @_;
  my ($m,$d,$y) = split '/', $date;
  my $time;
 
  $m--, $y -= 1900;  # $m is 9, $y is 100
  $time = timelocal(0,0,0,$d,$m,$y);
  $time += 86400 * $days;
  ($d,$m,$y) = (localtime($time))[3,4,5];
  return sprintf "%02d/%02d/%4d", $m+1, $d, $y+1900;
}

If you're doing more complex date computation, I highly suggest looking into the Date::Calc module, available on CPAN.

[Edited by japhy on 10-17-2000 at 05:21 PM]

Denise — Mon, 09 Oct 2000 18:22:54 +0000

Thanks all,

I had:

if($day < 10) {$day = "0$day";}
if($month < 10) {$day = "0$month";}

So I think we're all in the same ball park!

Denise

Rob Pengelly — Mon, 09 Oct 2000 16:29:22 +0000

I don't know of a 'proper' way to do it. But this would work:

$num="0$num",if(length($v)==1);

Vincent Puglia — Mon, 09 Oct 2000 16:02:08 +0000

Hi Denise,

Do you mean something like:

if (x < 10) print("0",x)

BTW: my perl is shaky, so I'm hoping Ken will correct the syntax if it's wrong

vinny

Denise — Sun, 08 Oct 2000 21:28:11 +0000

Hi Vincent,

Thanks for the tip but I eventually worked out a Perl sub routine. The only thing I'm stuck on now is displaying the date correctly. Well, I can bluff a way around it but was wondering whether anyone knew the easiest/proper way of displaying integers in two figures. ie: 1 to "01" and 2 to "02"?

Denise

Vincent Puglia — Sat, 07 Oct 2000 20:04:25 +0000

Hi Denise,

Don't really remember the exact syntax, but in javascript something like:

var myMSec = myDate.getMilliseconds(); // myDate is 10/3/00 in date format
var myDaysinMSec = numOfDays * (60 * 60 * 24 * 1000)
var totalMsecs = myMSec + myDaysinMSec;
var newDate = setTime(totalMsecs);

I'll check later tonight, but if someone knows for certain, please slap me over the head and correct the code. Thanks
Vinny