osx man page for perlio::mmap

PerlIO::mmap(3pm)					 Perl Programmers Reference Guide					 PerlIO::mmap(3pm)

NAME
       PerlIO::mmap - Memory mapped IO

SYNOPSIS
	open my $fh, '<:mmap', $filename;

DESCRIPTION
       This layer does "read" and "write" operations by mmap()ing the file if possible, but falls back to the default behavior if not.

IMPLEMENTATION NOTE
       "PerlIO::mmap" only exists to use XSLoader to load C code that provides support for using memory mapped IO. One does not need to explicitly
       "use PerlIO::mmap;".

perl v5.16.2							    2012-10-25							 PerlIO::mmap(3pm)