centos man page for do_splice_direct

DO_SPLICE_DIRECT(9)						    splice API						       DO_SPLICE_DIRECT(9)

NAME
       do_splice_direct - splices data directly between two files

SYNOPSIS
       long do_splice_direct(struct file * in, loff_t * ppos, struct file * out, loff_t * opos, size_t len, unsigned int flags);

ARGUMENTS
       in
	   file to splice from

       ppos
	   input file offset

       out
	   file to splice to

       opos
	   output file offset

       len
	   number of bytes to splice

       flags
	   splice modifier flags

DESCRIPTION
       For use by do_sendfile. splice can easily emulate sendfile, but doing it in the application would incur an extra system call (splice in +
       splice out, as compared to just sendfile). So this helper can splice directly through a process-private pipe.

COPYRIGHT
Kernel Hackers Manual 3.10					     June 2014						       DO_SPLICE_DIRECT(9)