require "timelocal.pl";

@old_time = ($sec, ..., $isdst);
$old_seconds = &timelocal( @old_time);
$new_seconds = time();

if ( $new_seconds - $old_seconds > 3600 * 24 * 15) {
   print "Interval is greater than 15 days\n";
}
[download]

Anyway, could you giva a little more detail? What is the original form of the two dates being compared? (Seconds since the epoch? "Mnth Dy Year HH:MI:SS"? Something else?) I don't recall now whether Perl 4 has both the "localtime" and the "timelocal" functions -- if so, you might be able to work with those.

update: OK, having seen your reply, one more question... (warning: heading for Klugeville here): I gather you don't need accuracy to the hour, minute or second -- you just need to count the days between two given dates. So, what sort of time-depth do you have to deal with? Any dates before 1900? Before 1970?

If there is a definite threshold date, such that no computation will involve a date before that, you could establish that date as the start of your own "epoch". Then, you could use a modern version of perl on some other system (or use any tool of your choice) to create a look-up table of months and years: for each month/year, the table gives the number of days from the beginning of your epoch to the beginning of the month. Format this table in such a way that your Perl 4.x script can "require date_lookup.tbl", or simply read the table data into an array a hash.

Given such a table, you can easily take any two date strings convert them to "number of days since start of the epoch" (use month/year to get the table index and add the day-of-month to that), and then just subtract to get the number of days between them.

It'd be a huge amount of trouble, trust me. Have you ever had to deal with getting something approved by the government? The original format is a simple forward slash (or dash) delimited string, with the month, day, and year (i.e. - 12/31/1990). Perl 4 does have localtime, so I am able to get the current date information. Timelocal, however, is not available.

#!/usr/local/bin/perl4

# Global config option for hours off of GMT.  i.e. EST is -5.
# NOTE: You may want to use something like 4.5 to average when Dayligh
+t
# savings time is in affect.

$GMToffset = -5;

# We Run from the commandline as sample program
$diff = &diffTime($ARGV[0], $ARGV[1]);
print "Diff Seconds: $diff\n";
$diffDays = $diff/(3600*24);
print "Diff Days: $diffDays\n";

if ($diffDays < -16) {    ### NOTE that it's negative for past days.
  print "\n*** Windows up for more than 16 days!\n";
}
exit(0);


# FUNCTION: diffTime (date time)
# Usage &difftime( DD/MM/YYYY [HH:MM:SS] )
# A hyphen may be used as the date separator. only colons valid for ti
+me
# Returns seconds from current time.  Negative for past events Posotiv
+e for
# future events.
sub diffTime {
   local($rebootDate, $rebootTime, $rDmon, $rDday, $rDyear, $rDhour, $
+rDmin, $rDsec);
   local(@monthdays);
   local($sec, $leapCount, $i, $time);

   $rebootDate = $_[0];   # First Argument
   $rebootTime = $_[1];   # Second Argument

   unless (($rDmon, $rDday, $rDyear) = $rebootDate =~ /(\d{1,2})[\/-]{
+1}(\d{1,2})[\/-]{1}(\d{4})/) {
      print STDERR "Invalid Date\n\n";
      exit(1);
   }

   @monthdays=(31,28,31,30,31,30,31,31,30,31,30,31);

   ### NOTE: This will break in the year 2100
   if ($rDyear%4 == 0) { $monthdays[2]=29; }
   $sec = ($rDyear - 1970 ) * 365 * 24 * 60 * 60;
   $leapCount = int(($rDyear - 1972) / 4);
   $sec = $sec + ($leapCount * 24 * 60 * 60);

   for ( $i = $rDmon-2; $i >= 0; $i--) {
      $sec = $sec + ( $monthdays[$i] * 24 * 60 * 60);
   }
   $sec = $sec + ($rDday * 24 * 60 * 60);
   if ($rebootTime) {
      unless (($rDhour, $rDmin, $rDsec) = $rebootTime =~ /(\d{1,2})[:]
+{1}(\d{1,2})[:]{1}(\d{1,2})/) {
         print STDERR "Invalid Time\n\n";
         exit(2);
      }
      $sec = $sec + ($rDhour * 3600) + ($rDmin * 60) + $rDsec;
   }
   unless ($GMToffset) { $GMToffset = 0; }
   $time = time() + $GMToffset * 60 * 60;
   return $sec - $time;
}
[download]

Where are you getting the date from? If it is a file modification date, you could just check like this:

if (-M $filename > 15) {
    print("Reboot more than 15 days ago.");
}
[download]

(No, I haven't tested this, especially on perl4 on Windows.)

The only way something like this would work is if there is a Windows file that is written to whenever the system is rebooted. Again, the systems are locked down, so I have few options for finding the system uptime on Windows. The only thing I've found so far that gives any indications is the 'net statistics' command. I know this is a pain in the a$$. When I can use Perl 5 I do. If I had the option, I'd be able to write this in no time. With Perl 4, however, I'm a bit stuck. I appreciate the responses guys. How difficult do you think it'd be to write my own date difference subroutines? I'd imagine it's quite involved since there's an entire module dedicated to this alone.

Abandon all hope now. Perl 4.0.36 is at least a decade old and didn't support modules. You'd be better served by getting a more reasonable sysadmin.

Come on ... if they want scripts, they should seriously consider migrating to 21-st century software. If old scripts need Perl 4, Perl 5 could be installed as perl5.

After all, we no longer have a man walk a hundred feet in front of a car, waving a red lantern to warn people of the approaching hazard. ..... Do we?

After all, we no longer have a man walk a hundred feet in front of a car, waving a red lantern to warn people of the approaching hazard. ..... Do we?

If it's the government agency with whom I used to contract, that is precisely what they'd do.

--
tbone1, YAPS (Yet Another Perl Schlub)
And remember, if he succeeds, so what.
- Chick McGee