True. Changing a variable in memory will not change a file. Except when using Tie::File which should be perfect for you.

Normally, to change something in a file, you need to read the file, do your change, and write the file back out. 

use strict;
use warnings;

use POSIX     qw( strftime );
use Text::CSV qw( );
use Tie::File qw( );

use constant INHOUSE =>"Open House Information";

{
   my $today = strftime('%Y/%m/%d', localtime());

   tie(my @db, 'Tie::File', 'dbase1.exm')
      or die("Unable to open database: $!\n");

   my $csv = Text::CSV->new();

   foreach my $line (@db) {
      $csv->parse($line)
         or die("Unable to parse \"$line\"\n");

      my @fields = $csv->fields();
      my ($status, $date) = $fields[22, 23];

      # Convert date to sortable format.
      my ($m, $d, $y) = split(/\//, $date);
      $date = "20$y/$m/$d";

      my $kill = ($date < $today);  # Are you sure this isn't backward
+s?

      if ($status eq INHOUSE && $kill) {
         $status = '';
      }

      # Reassemble the line and updated the file.
      $fields[22] = $status;

      $csv->combine(@fields)
         or die("Unable to recreate line from fields @fields\n");

      # Changing $line causes the file to be updated.
      $line = $csv->string();
   }

   untie @db;
}

[download]

If you're trying to remove the entire line, it's even easier: 

use strict;
use warnings;

use POSIX     qw( strftime );
use Text::CSV qw( );
use Tie::File qw( );

use constant INHOUSE =>"Open House Information";

{
   my $today = strftime('%Y/%m/%d', localtime());

   tie(my @db, 'Tie::File', 'dbase1.exm')
      or die("Unable to open database: $!\n");

   my $csv = Text::CSV->new();

   @db = grep {
      $csv->parse($line)
         or die("Unable to parse \"$line\"\n");

      my @fields = $csv->fields();
      my ($status, $date) = $fields[22, 23];

      # Convert date to sortable format.
      my ($m, $d, $y) = split(/\//, $date);
      $date = "20$y/$m/$d";

      $status ne INHOUSE || $date >= $today
   } @db;

   untie @db;
}

[download]

In reply to Re^3: replace in lines by ikegami
in thread replace in lines by pglinx

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.