PerlIO::mmap - Memory mapped IO

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

"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 v5.40.1 2025-07-03 PerlIO::mmap(3perl)

PerlIO::mmap - Memory mapped IO

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