There is a module that lets me access a scalar variable as if it were a file: Tie::Handle::Scalar but I can't seem to find one to do the opposite - access a file as if it were a scalar variable.

The reason I want to do this is that I was looking at YAPE::HTML and it wanted a string containing HTML to parse and I had an HTML file. If I could get YAPE::HTML to think it had a string but was really accessing my file then I wouldn't have to slurp it in (not such a big problem for relatively small files but Out of memory! errors lurk around every corner).

After a while in the CB I couldn't find a suitable wheel. I looked at perldoc perltie but it won't let me override the core string functions. I decided the only way was to create an object and somehow force any string ops to use the object's methods - fine if I am writing the script as I can say $pseudo_string->substr(0,10) but not so fine if I am trying to fool A::N::Other package into thinking it has got a real scalar variable that it can do substr($pseudo_string,0,10). I read the WARNING section in perldoc perlobj about indirect object syntax and while my proposed solution does not suffer from the first problem:

The first problem is that an indirect object is limited to a name, a
scalar variable, or a block, because it would have to do too much
lookahead otherwise...

As if that weren't bad enough, think about this: Perl must guess *at
compile time* whether "name" and "move" above are functions or methods.
Usually Perl gets it right, but when it doesn't it, you get a function
call compiled as a method, or vice versa.

I made a start (see code below) but the only way I can substr my $pseudo_string using indirect syntax is by fully qualifying the method name: Pseudo::Tie::Scalar::Handle::substr $pseudo_string, 10, 20. Which defeats the purpose if I have to then modify A::N::Other package.

Am I barking up the wrong tree? Or just barking? How can I force the indirect syntax of A::N::Other package to call the $pseudo_string's methods instead of core functions?

package Pseudo::Tie::Scalar::Handle;
use strict;
use warnings;

use Fcntl;
use IO::File;

sub new {
    my($class,$file) = @_;
    my $fh = IO::File->new($file,O_RDWR|O_CREAT);
    return unless defined $fh;
    bless {
        file   => $file,
        handle => $fh,
    }, $class;
}

sub AUTOLOAD {
    no strict 'vars';
    warn "$AUTOLOAD not implemented for a Pseudo::Tie::Scalar::Handle 
+object\n";
}

sub DESTROY {}

sub substr ($$;$$) {
    my $self = shift;
    my $fh = $self->{handle};
    seek $fh, shift, 0;
    my $size = shift;
    my $chunk;
    if (defined $size) {
        warn "substr replacement not implemented\n" if @_;
        read $fh, $chunk, $size;
    } else {
        $chunk = do { local $/; <$fh> }
    }
    return $chunk;
}

1;

package main;
use strict;
use warnings;

my $pseudo_string = Pseudo::Tie::Scalar::Handle->new('/test.txt');

print "\nnot-working: ",substr $pseudo_string, 0, 43;
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   larryk                                          
perl -le "s,,reverse killer,e,y,rifle,lycra,,print"