Module for calculating previous day's date

[sangith]

Hi,

Is there any module which checks for the previous day's date. For eg I run the program which gives me the current date and I have to check another log file to see if it contains the timestamp as the previous day's date. If it is present, I have to print that particular line to the screen.

So please let me know if there is a module available to check for the previous day date.

Thanks,
Sangith

[miller]

You'll have to calculate it. Look into this module for date manipulation routines:

cpan Date::Calc

- Miller

[sangith]

Thanks for your reply. I will look into the document that you mentioned.

Thanks,
Sangith

[KevinADC]

if you can get the date/time in seconds from the epoch calculating yesterdays date is very easy:

$yesterday = time - 86400;
print scalar $yesterday;

[alcazar]

You can even use localtime as below with some simple manipulations as below.

$yesterday_date=get_yesterday();
print "$yesterday_date";
 
sub get_yesterday
{
my ($csec,$cmin,$chr,$cmday,$cmon,$cyear,$cwday,$cyday) = localtime(time) ;
 
  $cmday-=1;
  if(length($cmday) == 1) { $cmday = '0' . $cmday }
 
  $cmon+=1;
  if(length($cmon) == 1) { $cmon = '0' . $cmon }
 
  $cyear+=1900;
 
  my $cDate = "$cmday/$cmon/$cyear";
 
return $cDate;
}

NOTE:localtime function would return the time which is set on the local macine/web server on which the perl script is executed.

cheers,
Alcazar

Thanks for your reply. I will look into the document that you mentioned.

Thanks,
Sangith

[KevinADC]

alcazar,

the better way is to subtract a days worth of seconds from time:

my ($csec,$cmin,$chr,$cmday,$cmon,$cyear,$cwday,$cyday) = localtime(time-86400) ;

now you accurately have yesterdays date.

Your suggested way will not always work properly. For example, if the day of the month is 1 (one), you will end up with zero after subtracting one day. There is no such day in a month as zero. Also, the month will not roll back properly either.

Kevin

[miller]

You can even use localtime as below with some simple manipulations as below.

Yes, as Kevin said, rolling your own data calculation routines is a waste of time. Either do calculations in time since epoch, or use the Date::Calc module to manipulate based individual date parts. There is no reason to do it otherwise, and plenty of reasons not to.

- Miller