#!/usr/bin/perl -w
use strict;

use Time::Local;
use POSIX qw(strftime);

####### how to get mtime from a file #########
my @Month_text = qw(Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec);

my $source_path = "./testfile";

(my $m_time) = (stat($source_path))[9] or die "stat failed";
my ($i_month, $day, $year, $hour, $minutes) = (localtime($m_time))[4,3,5,2,1];
$year += 1900;
    
printf "%s %2d %4d %d:%d\n",$Month_text[$i_month],$day,$year,$hour,$minutes,"\n";

#### parsing a date to put into timegm  ######

my $test = "2004-09-03 23:58";
print "starting unparsed string=$test\n";
( $year, my $month, my $days, my $hours,  $minutes) = 
	$test =~ m/\s*(\d+)-(\d+)-(\d+)\s*(\d+):(\d+)/;

print "testing parsed vales    =$year-$month-$days $hours:$minutes \n";

######### The key epoch second routine  #####

#remember for timegm month[0-11] and year is delta from 1900
my $time = timegm(0,$minutes,$hours,$days,$month-1,$year-1900);
print "epoch seconds $time\n";

print "running gmtime() to convert back to components\n";
(my $seconds, $minutes, $hours, $days, $month, $year) = gmtime($time);

printf("the printf version=%04d-%02d-%02d %02d:%02d \n",
  $year+1900, $month+1, $days, $hours, $minutes);

#note don't have to adjust as strftime is using C time structure
print "now running strftime format".'=%Y-%m-%d %H:%M'."\n";
my $str = strftime( "strfttime version =%Y-%m-%d %H:%M ", 
                    0, $minutes, $hours, $days, $month,$year);
print "$str\n";
        
my $string = gmtime($time);
print "string in scalar context from gmtime=$string\n";


__END__
Mar 27 2009 9:30
starting unparsed string=2004-09-03 23:58
testing parsed vales    =2004-09-03 23:58 
epoch seconds 1094255880
running gmtime()
the printf version=2004-09-03 23:58 
now running strftime format=%Y-%m-%d %H:%M
strfttime version =2004-09-03 23:58 
string in scalar context from gmtime=Fri Sep  3 23:58:00 2004