in reply to Sorting according to date

Use Date::Calc, here is an example: 
#! /usr/bin/perl -w

use CGI qw/:standard/;
# first install module Date::Calc
use Date::Calc qw(Date_to_Days Add_Delta_Days check_date);

#@array=readpipe 'ls 'directory'/'subdirectory'.*html' ;
@array=readpipe 'ls ./tmp/*html' ;

# we will be sorting later
#sort @array;

@headings=('Title','Issue Date');
@rows=th(\@headings);
foreach $n (@array)
{
    open (HTMLFILE,$n);
    $issue_date="";
    while (<HTMLFILE>)
    {
        if (m/<TITLE>(.+)<\/TITLE>/i){$title=$1};
#        had to change / in the middle?
        if (m/<o:Description>(.+)<o:Description>/i)
        {$issue_date=$1};
    }
    close HTMLFILE;

    #push(@rows, td([$title,$issue_date])
    push(@temp_rows,[$title, $issue_date,
                    # in case your date looks like "DD.MM.YYYY"
                    Date_to_Days((split(/\./, $issue_date, 3))[2,1,0])
                     ]);
}
for my $i (sort {$a->[2] <=> $b->[2] } @temp_rows) {
    push(@rows, td([@{$i}[0,1]]));
}
print
table({width=>"100%",border=>"1",bordercolor=>"#d9dae6",cellspacing=>"
+1",cellpadding=>"1"},Tr({bgcolor=>"#97a5f0"},\@rows));

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Re: Re: Sorting according to date
by sauoq (Abbot) on Jun 09, 2003 at 21:19 UTC

    First you assume the date format he is using and then you go on to suggest a byzantine method of sorting dates in that format...

    If his dates really are in a format like "DD.MM.YYYY" then Date::Calc is hardly necessary: 

    my @sorted = map  { $_->[0] }
             sort { $a->[1] <=> $b->[1] }
             map  { [ $_, join "", reverse (split /\./) ] }
             @dates;

    [download]

    -sauoq
"My two cents aren't worth a dime.";
[reply]
[d/l]
      I like your solution, it is elegant but a bit slower. Conversion of date strings to integers is expensive, but it pays off in the sorting faze. Dates that are close together have 4 to 6 equal characters from the beginning of the string, and the for loop is also faster than map. I made a couple of benchmarks to verify that. The difference in speed is not significant.
      I had to assume some date format to be able to produce working solution. It is easy to modify for different format.
[reply]
        Thank you, O enlightened ones.

        Regards

        Campbell

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