FFI::Raw::MemPtr - FFI::Raw memory pointer type


version 0.32


A FFI::Raw::MemPtr represents a memory pointer which can be passed to functions taking a FFI::Raw::ptr argument.

The allocated memory is automatically deallocated once the object is not in use anymore.


new( $length )

Allocate a new FFI::Raw::MemPtr of size $length bytes.

new_from_buf( $buffer, $length )

Allocate a new FFI::Raw::MemPtr of size $length bytes and copy $buffer into it. This can be used, for example, to pass a pointer to a function that takes a C struct pointer, by using pack() or the Convert::Binary::C module to create the actual struct content.

For example, consider the following C code

    struct some_struct {
      int some_int;
      char some_str[];

    extern void take_one_struct(struct some_struct *arg) {
      if (arg -> some_int == 42)
        puts(arg -> some_str);

It can be called using FFI::Raw as follows:

    use FFI::Raw;

    my $packed = pack('ix![p]p', 42, 'hello');
    my $arg = FFI::Raw::MemPtr -> new_from_buf($packed, length $packed);

    my $take_one_struct = FFI::Raw -> new(
      $shared, 'take_one_struct',
      FFI::Raw::void, FFI::Raw::ptr

    $take_one_struct -> ($arg);

Which would print hello.

new_from_ptr( $ptr )

Allocate a new FFI::Raw::MemPtr pointing to the $ptr, which can be either a FFI::Raw::MemPtr or a pointer returned by another function.

This is the FFI::Raw equivalent of a pointer to a pointer.

tostr( [$length] )

Convert a FFI::Raw::MemPtr to a Perl string. If $length is not provided, the length of the string will be computed using strlen().


Alessandro Ghedini <>


Copyright 2013 Alessandro Ghedini.

This program is free software; you can redistribute it and/or modify it under the terms of either: the GNU General Public License as published by the Free Software Foundation; or the Artistic License.

See for more information.