How to add an hour or a minute to a time?


 
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# 15  
Old 07-26-2011
Thanks radoulov. It works.

Can you please explain what is the difference between the two, in what cases each has to be used and why doesnt $date_var != '' work?
# 16  
Old 07-26-2011
Numerical and string comparisons require different operators.

This is from perldoc perlop:

Quote:
Relational Operators
Binary "<" returns true if the left argument is numerically less than
the right argument.

Binary ">" returns true if the left argument is numerically greater
than the right argument.

Binary "<=" returns true if the left argument is numerically less than
or equal to the right argument.

Binary ">=" returns true if the left argument is numerically greater
than or equal to the right argument.

Binary "lt" returns true if the left argument is stringwise less than
the right argument.

Binary "gt" returns true if the left argument is stringwise greater
than the right argument.

Binary "le" returns true if the left argument is stringwise less than
or equal to the right argument.

Binary "ge" returns true if the left argument is stringwise greater
than or equal to the right argument.

Equality Operators
Binary "==" returns true if the left argument is numerically equal to
the right argument.

Binary "!=" returns true if the left argument is numerically not equal
to the right argument.


Binary "<=>" returns -1, 0, or 1 depending on whether the left argument
is numerically less than, equal to, or greater than the right argument.
If your platform supports NaNs (not-a-numbers) as numeric values, using
them with "<=>" returns undef. NaN is not "<", "==", ">", "<=" or ">="
anything (even NaN), so those 5 return false. NaN != NaN returns true,
as does NaN != anything else. If your platform doesn't support NaNs
then NaN is just a string with numeric value 0.

perl -le '$a = "NaN"; print "No NaN support here" if $a == $a'
perl -le '$a = "NaN"; print "NaN support here" if $a != $a'

Binary "eq" returns true if the left argument is stringwise equal to
the right argument.

Binary "ne" returns true if the left argument is stringwise not equal
to the right argument.


Binary "cmp" returns -1, 0, or 1 depending on whether the left argument
is stringwise less than, equal to, or greater than the right argument.

Binary "~~" does a smart match between its arguments. Smart matching is
described in "Smart matching in detail" in perlsyn.

"lt", "le", "ge", "gt" and "cmp" use the collation (sort) order
specified by the current locale if "use locale" is in effect. See
perllocale.
This User Gave Thanks to radoulov For This Post:
# 17  
Old 07-29-2011
Hi,

This works perfectly fine.
But, $my $min_to_add = 1 * 1 * 60; and my $hr_to_sub = 1 * 1 * 86400; i may need to change the values in future. so am keeping them in a separate configuration file like

Code:
MIN = 1 * 1 * 60 
HR = 24 * 60 * 60

in the script, i use a package use et_config and Et_Config_Init()
I call them inside the script like
Code:
my $min_to_add = Et_Config_Value("MIN");
my $hr_to_sub = Et_Config_Value("HR");

The issue here is, when i use those values directly in the script, it takes the multiplied value as 1 * 1 * 60 =60 but when i get them from the configuration file, it remains as 1 * 1 * 60 only as such , so i am not getting the result expected.

Is there any function that can do this?
The configuration file is mandatory. How can this be achieved?

Code:

Code:
my $date_var = "Jun  6 2011  8:02AM";
if ($date_var != '')
{
my $min_to_add = 1 * 1 * 60;
my $from_dt = qx/
  date -d "$date_var" +%s
  / + $min_to_add;
my $min_var = strftime( '%B %d %Y %I:%M%p', localtime $from_dt );
print("\n the mins added  is $min_var\n");

my $hr_to_add = 1 * 60 * 60;
my $to_dt = qx/
  date -d "$min_var" +%s
  / + $hr_to_add;
my $hr_var = strftime( '%B %d %Y %I:%M%p', localtime $to_dt );
print("\n the hours  added is $hr_var\n");
}
else
{
use POSIX qw(strftime);
my $to_dt = strftime "%b %d %Y %H:%M%p", localtime;
print("\n The original time is  $to_dt\n");
my $hr_to_sub = 1 * 1 * 86400;
my $from_dt
 = qx/
  date -d "$to_dt" +%s
  / - $hr_to_sub;
my $to_dt_now = strftime( '%B %d %Y %H:%M%p', localtime $from_dt );
print("\n the to date now  is $to_dt_now \n");
}


Last edited by radoulov; 07-29-2011 at 10:33 AM.. Reason: Please use code tags!
# 18  
Old 07-29-2011
This is what I would store in the configuration file:

Code:
MIN = 1
HR = 24

And I'll calculate the values in run-time:

Code:
my $min_to_add =  Et_Config_Value("MIN") * 60;
...

 
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