System date and substraction

[TecnoAlpha]

Hello Guys,

I'm biggener to perl and i want to get the system date and do substraction from it as the below example:

Get the system date say in this format: 04-08-08

Do substraction say -2 so the result will be 02-08-08

So can you help me guys to get the right procedure to get the systm date and be able to do substraction to get the proper result.

Appreciate it.

- TecnoAlpha

 

[max1x]

As other will point out, what have you tried or so far and if this is school work.

You can take a look at perl module Date::Calc.

In a *nix based env
$date = `date +%d-%m-%y`;
or @myDate = localtime() and then get the necessary fields.

 

[TecnoAlpha]

Hello max1x,

LOL =), well I'm working as a system engineer, and im trying to learn perl by my self, and practice.

I got the system date by:
my $now = localtime time;

but the issue once i tried to call Date::Calc, i got the below:

Can't locate Date/Calc.pm in @INC (@INC contains: /usr/lib/perl5/5.8.5/i386-linux-thread-multi /usr/lib/perl5/5.8.5 /usr/lib/perl5/site_perl/5.8.5/i386-linux-thread-multi /usr/lib/perl5/site_perl/5.8.4/i386-linux-thread-multi /usr/lib/perl5/site_perl/5.8.3/i386-linux-thread-multi /usr/lib/perl5/site_perl/5.8.2/i386-linux-thread-multi /usr/lib/perl5/site_perl/5.8.1/i386-linux-thread-multi /usr/lib/perl5/site_perl/5.8.0/i386-linux-thread-multi /usr/lib/perl5/site_perl/5.8.5 /usr/lib/perl5/site_perl/5.8.4 /usr/lib/perl5/site_perl/5.8.3 /usr/lib/perl5/site_perl/5.8.2 /usr/lib/perl5/site_perl/5.8.1 /usr/lib/perl5/site_perl/5.8.0 /usr/lib/perl5/site_perl /usr/lib/perl5/vendor_perl/5.8.5/i386-linux-thread-multi /usr/lib/perl5/vendor_perl/5.8.4/i386-linux-thread-multi /usr/lib/perl5/vendor_perl/5.8.3/i386-linux-thread-multi /usr/lib/perl5/vendor_perl/5.8.2/i386-linux-thread-multi /usr/lib/perl5/vendor_perl/5.8.1/i386-linux-thread-multi /usr/lib/perl5/vendor_perl/5.8.0/i386-linux-thread-multi /usr/lib/perl5/vendor_perl/5.8.5 /usr/lib/perl5/vendor_perl/5.8.4 /usr/lib/perl5/vendor_perl/5.8.3 /usr/lib/perl5/vendor_perl/5.8.2 /usr/lib/perl5/vendor_perl/5.8.1 /usr/lib/perl5/vendor_perl/5.8.0 /usr/lib/perl5/vendor_perl .) at ./test2.pl line 5.
BEGIN failed--compilation aborted at ./test2.pl line 5.


Looks this API is not included in the Perl library, isn't there an easy way just to subtract from the system date !!!

Thanks.

 

[stevexff]

If there was an easy way to do it, no-one would have bothered to write the Date::Calc module.

The system date is held as the number of seconds since 00:00:00 on Jan 1 1970. All localtime does is format it to make it more readable. So to subtract two days you'd need something like

my $two_days_ago = localtime(time - (2 * 1440 * 60));

which is a bit clunky.

You can install Date::Calc easily using CPAN if you have root access.

Steve

[small]"Every program can be reduced by one instruction, and every program has at least one bug. Therefore, any program can be reduced to one instruction which doesn't work." (Object:erlDesignPatterns)[/small]

 

[TecnoAlpha]

Hi Steve, got ur point, at least i know how it works now.

I'll manage to try both, appreciate it =)

All regards.

 

[prex1]

If you want to subtract [tt]$nd[/tt] days from present time you just do
[tt]$ago=time-$nd*86400;[/tt]
then you normally transform this in a [tt]localtime[/tt] for displaying purposes,e.g.
[tt]print scalar localtime$ago;[/tt]

Franco

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