Will this do it for you?

#!/usr/bin/env perl

# Just because you can be a SOB doesn't mean you should
# or among the things you probably shouldn't do is this:
#     modify (read/write) the program's DATA section -
#     but hey, it was interesting and amusing.

use Carp;
use English qw(-no_match_vars);
use strict;
use warnings;

    open my $READER,'+<',$PROGRAM_NAME
        or Carp::confess "Can't open '$PROGRAM_NAME'! $OS_ERROR";
    open my $WRITER,'+<',$PROGRAM_NAME                      # Don't us
+e '+>'
        or Carp::confess "Can't open '$PROGRAM_NAME'! $OS_ERROR";
    seek $READER,tell DATA ,0;
    seek $WRITER,tell DATA,0;
    # The overflow buffer:
    my @Buffer_a;
    #print "READER: @{[tell $READER ]} \n";
    while (<$READER>) {
        #print "Read: '$_'\n";
        # Read (past tense) a line - buffer its replacement ...
        {
            # Modify the line here!
            my $Update_s="x s $_";

            push @Buffer_a,$Update_s;
            };

        #print "WRITER: @{[tell $WRITER ]} \n";
        # Write from the overflow buffer if we can ...
        while (@Buffer_a && tell($READER)-tell($WRITER) > length $Buff
+er_a[0]) {
            # Enough room to write $Buffer_a[0] so write it ...
            #print "Writing '$Buffer_a[0]'\n";
            print {$WRITER} shift @Buffer_a
                or Carp::confess "Error while writing \$WRITER: $OS_ER
+ROR";
            #print "WRITER: @{[tell $WRITER]} \n";
             };
        #print "READER: @{[tell $READER]} \n";
         };
    # Nothing more to read ...
    close $READER
        or Carp::confess "Can't close '$PROGRAM_NAME'! $OS_ERROR";
    #print "WRITER: @{[tell $WRITER]} \n";
    # If there's anything in the buffer write it ...
    while (@Buffer_a) {
        #print "Writing '$Buffer_a[0]'\n";
        print {$WRITER} shift @Buffer_a
            or Carp::confess "Error while writing \$WRITER: $OS_ERROR"
+;
        #print "WRITER: @{[tell $WRITER]} \n";
         };
    # Truncate the file, in case, what we're writing is shorter than w
+hat we read
    truncate $WRITER,tell$WRITER;
    #  ... and close
    close $WRITER
        or Carp::confess "Can't close '$PROGRAM_NAME'! $OS_ERROR";
    exit;

__END__
0
1
2
3
4
5
6
7
8
9
[download]

---

---

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! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

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:
	&		&
	<		&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.