You could do this with the __END__ tag. Just keep your number there. Something like the following would work (actually tested and updated, but occasionally I get one right): 
#!/usr/bin/perl -w

use strict;

chomp(my $num = <DATA>);

print "My counter is set to $num.\n";

$num++;

{
    local *FILE;
    local $/ = "\n__END__";
    open (FILE, "counter.pl") || die "Can't open my file for reading: 
+$!\n";
    chomp(my $file = <FILE>);
    close FILE;
    open (FILE, ">counter.pl") || die "Can't open file for writing: $!
+";
    print FILE $file, "\n__END__\n$num";
    close FILE;
}
__END__
0

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I wouldn't do it this way, though. It's easy to get these wrong and overwrite your program in the blink of an eye, and it's easy to use one of the DBM modules that comes with Perl and get things right. Still, it's good to know some of these techniques.

In reply to Re: Self-Modifying-Perl-Script by chromatic
in thread Self-Modifying-Perl-Script by crazyinsomniac

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