NAME

       io_sendfile - send data from a file to a socket

SYNTAX

       #include <io.h>

       int64 io_sendfile(int64 sock,int64 fd,uint64 off,uint64 n);

DESCRIPTION

       io_sendfile  sends  data from a file to a socket.  This function tries to do this in a way
       that allows high quality operating systems to do zero-copy TCP (serving the  data  without
       copying  the  file contents to user space or inside kernel space).  This function will use
       special operating system "sendfile" primitives where available and use memory  mapped  I/O
       otherwise.   It  should  always  be  faster than using read() and write() to copy the data
       yourself.

       io_sendfile will return the number of bytes sent.  If an error occurred, it will return -1
       for EAGAIN, or -3 otherwise.

SEE ALSO

       io_wait(3), io_waituntil(3)

                                                                                   io_sendfile(3)