NAME

    PeekPoke::FFI - Perl extension for reading and writing to arbitrary
    memory locations

VERSION

    version 0.02

SYNOPSIS

     # function interface
     use PeekPoke::FFI qw( peek poke );
     my $value = peek( 0xdeadbeaf );
     poke( 0xdeadbeaf, $value + 1 );
    
     # OO-interface
     use PeekPoke::FFI;
     my $pp = PeekPoke::FFI->new( type => 'sint32', base => 0xdeadbeaf );
     my $value = $pp->peek( 0xdeadbeaf );
     $pp->poke( 0xdeadbeaf, 0 - $value );

DESCRIPTION

    Very occasionally I need to get/set bytes from arbitrary bits of memory
    from a Perl script or module. If you know what you are doing it isn't
    too tricky to get an arbitrary byte from Perl. Setting one is a little
    harder, but can be done with tricks. This module implements these
    tricks so that I don't have to remind myself of how to do it the next
    time I need to reach for this particular tool.

CONSTRUCTOR

 new

     my $pp = PeekPoke::FFI->new(%opts);

    Create a PeekPoke::FFI instance. If you need to get/set values other
    than bytes, or if you want to set a base address, then you will want to
    create

    type

      The FFI::Platypus type to use for peeking and poking. Defaults to
      uint8. Only integer and floating point types are supported.

    base

      The base address to use. The offset will be added to this value.

METHODS

 peek

     my $value = $pp->peek($offset);
     my $value = peek($offset);

    Get the value at the given offset.

 poke

     $pp->poke($offset, $value);
     poke($offset, $value);

    Set the value at the given offset.

CAVEATS

    Most of the time you shouldn't be peeking and poking at random bits of
    memory. Sometimes during development it can be useful for various
    reasons. Use with extreme caution in production.

SEE ALSO

    PeekPoke

      This is an XS module that has been around for donkey's years. It only
      works with the native Perl integer values (IV) which is not usually
      what I want.

AUTHOR

    Graham Ollis <plicease@cpan.org>

COPYRIGHT AND LICENSE

    This software is copyright (c) 2020 by Graham Ollis.

    This is free software; you can redistribute it and/or modify it under
    the same terms as the Perl 5 programming language system itself.

