in reply to Finding Time Difference of Localtime

Don't use localtime in the first place. Use time or gmtime and POSIX::strftime instead.

#!/usr/bin/perl

use strict;
use warnings;
use POSIX qw(strftime);
my $start = time();
sleep 10;
my $end = time();
my $duration = $end - $start;
print "It took me $duration seconds\n";
my $start_date = strftime "%Y-%m-%d %H:%M:%S", localtime($start);
my $end_date = strftime "%Y-%m-%d %H:%M:%S", localtime($end);
print "I was started on $start_date and ended on $end_date\n";

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Updated after Aldebaran actually checked the code.

Replies are listed 'Best First'.
Re^2: Finding Time Difference of Localtime
by Aldebaran (Curate) on Dec 01, 2019 at 00:42 UTC
    Don't use localtime in the first place. Use time or gmtime and POSIX::strftime instead.

    I just happened on to this and wonder if this is the behavior that Corion was expecting out of this. This isn't "my thread" or anything; I was just searching (again) for ways to time programs. I'm hoping to find a native one that works on Termux.

    $ ./1.strftime.pl 
Argument "Sun Dec  1 00:29:42 2019" isn't numeric in subtraction (-) a
+t ./1.strftime.pl line 9.
Argument "Sun Dec  1 00:29:52 2019" isn't numeric in subtraction (-) a
+t ./1.strftime.pl line 9.
It took me 0 seconds
Usage: POSIX::strftime(fmt, sec, min, hour, mday, mon, year, wday = -1
+, yday = -1, isdst = -1) at ./1.strftime.pl line 11.
$ cat 1.strftime.pl 
#!/usr/bin/perl

use strict;    
use warnings;
use POSIX qw(strftime);
my $start = gmtime();
sleep 10;
my $end = gmtime();
my $duration = $end - $start;
print "It took me $duration seconds\n";
my $start_date = strftime "%Y-%m-%d %H:%M:%S", $start;
my $end_date = strftime "%Y-%m-%d %H:%M:%S", $end;
print "I was started on $start_date and ended on $end_date\n";

$

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[reply]
[d/l]

      Whoops! Thank you for checking this, that's not what I want.

      You want to use time, not gmtime, and use strftime( localtime( $start )) to turn the seconds back into strings.

      I'll fix the above post.

[reply]
[d/l]
        You want to use time, not gmtime, and use strftime( localtime( $start )) to turn the seconds back into strings.

        That gets us there:

        $ ./2.strftime.pl 
It took me 10 seconds
I was started on 2019-12-03 11:41:38 and ended on 2019-12-03 11:41:48
$ cat 2.strftime.pl

        [download]
        #!/usr/bin/perl
use strict;
use warnings;
use POSIX qw(strftime);
my $start = time();
sleep 10;
my $end      = time();
my $duration = $end - $start;
print "It took me $duration seconds\n";
my $start_date = strftime "%Y-%m-%d %H:%M:%S",(localtime($start));
my $end_date   = strftime "%Y-%m-%d %H:%M:%S",(localtime($end));
print "I was started on $start_date and ended on $end_date\n";

        [download]
        I'll fix the above post.

        Fixing a post from 2010 might have a butterfly effect. Getting better behavior from output is what happens with code review and replication in "the monastery."

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[d/l]
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