Try this 
#!/usr/bin/perl

use strict;
use warnings;

use Tie::File;
use Data::Dumper;

my $file = "file.txt";
my @lines;

#tie @lines, 'Tie::File', $file || die $!;
tie @lines, 'Tie::File', $file or die $!;

my @tmp = splice @lines;

push @lines, <STDIN>;
push @lines, @tmp;

untie @lines;

[download]
Tie::File isn't a standard module but its easily installed as it is pure Perl (i.e. doesn't need a C compiler installed).

CC

Updated: changed '||' to 'or'.

Another update

Given that whatever solution you choose will be running from a web page (via CGI), have you given any thought file locking? What if multiple copies of the CGI script are running at the same time? You could potentially lose a lot of data...

In reply to Re: writing to the top of a file by coec
in thread writing to the top of a file by Anonymous Monk

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.