Author image Dave Lambley
and 1 contributors

NAME

Linux::PipeMagic - Perl extension to use the zero copy IO syscalls

SYNOPSIS

  use Linux::PipeMagic qw/ systee syssplice /;
  systee($fh_in, $fh_out, $num_bytes, 0);
  syssplice($fh_in, $fh_out, $num_bytes, 0);

DESCRIPTION

Linux::PipeMagic is a Perl XS wrapper around the splice(2) and tee(2) syscalls. You can use them to efficiently data from one file descriptor to another inside the kernel (splice), or to efficiently copy data from one pipe to another (tee).

FUNCTIONS

sysplice($fh_in, $fh_out, $num_bytes, $flags)

Moves $num_bytes from $fh_in to $fh_out. This is roughly equivilent to,

    sysread($fh_in, my $buf, $num_bytes);
    syswrite($fh_out, $buf);

although the transfer takes place entirely in kernel-space.

Returns the number of bytes transferred.

systee($fh_in, $fh_out, $num_bytes, $flags)

Copies $num_bytes from $fh_in to $fh_out. The filehandles must both be of pipes. This works similarly to syssplice, but does not advance the read pointer in $fh_in.

Returns the number of bytes transferred.

CONSTANTS

  • SPLICE_F_MOVE

  • SPLICE_F_NONBLOCK

  • SPLICE_F_MORE

  • SPLICE_F_GIFT

SEE ALSO

See the Linux manpages for more details on how splice and tee can be used, including the flags.

AUTHOR

Dave Lambley, <cpan@davel.org.uk>

COPYRIGHT AND LICENSE

Copyright (C) 2011 by Dave Lambley

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.10.1 or, at your option, any later version of Perl 5 you may have available.