LinuxGuruz
  • Last 5 Forum Topics
    Replies
    Views
    Last post


The Web Only This Site
  • BOOKMARK

  • ADD TO FAVORITES

  • REFERENCES


  • MARC

    Mailing list ARChives
    - Search by -
     Subjects
     Authors
     Bodies





    FOLDOC

    Computing Dictionary




  • Text Link Ads






  • LINUX man pages
  • Linux Man Page Viewer


    The following form allows you to view linux man pages.

    Command:

    splice

    
    
    

    SYNOPSIS

           #define _GNU_SOURCE         /* See feature_test_macros(7) */
           #include <fcntl.h>
    
           ssize_t splice(int fd_in, loff_t *off_in, int fd_out,
                          loff_t *off_out, size_t len, unsigned int flags);
    
    
    

    DESCRIPTION

           splice()  moves  data  between  two  file  descriptors  without copying
           between kernel address space and user address space.  It  transfers  up
           to  len  bytes  of  data  from  the  file  descriptor fd_in to the file
           descriptor fd_out, where one of the descriptors must refer to a pipe.
    
           If fd_in refers to a pipe, then off_in must be NULL.  If fd_in does not
           refer  to  a  pipe  and  off_in is NULL, then bytes are read from fd_in
           starting from the current file offset, and the current file  offset  is
           adjusted  appropriately.   If fd_in does not refer to a pipe and off_in
           is not NULL, then off_in must point to a  buffer  which  specifies  the
           starting offset from which bytes will be read from fd_in; in this case,
           the current file offset of fd_in is not changed.  Analogous  statements
           apply for fd_out and off_out.
    
           The  flags  argument  is  a bit mask that is composed by ORing together
           zero or more of the following values:
    
           SPLICE_F_MOVE      Attempt to move pages instead of copying.   This  is
                              only a hint to the kernel: pages may still be copied
                              if the kernel cannot move the pages from  the  pipe,
                              or  if  the  pipe buffers don't refer to full pages.
                              The initial implementation of this flag  was  buggy:
                              therefore  starting  in  Linux  2.6.21 it is a no-op
                              (but is still permitted in a splice() call); in  the
                              future, a correct implementation may be restored.
    
           SPLICE_F_NONBLOCK  Do  not  block  on  I/O.  This makes the splice pipe
                              operations nonblocking, but splice()  may  neverthe-
                              less  block  because  the  file descriptors that are
                              spliced to/from may  block  (unless  they  have  the
                              O_NONBLOCK flag set).
    
           SPLICE_F_MORE      More  data  will  be  coming in a subsequent splice.
                              This is a helpful hint when the fd_out refers  to  a
                              socket  (see  also  the  description  of MSG_MORE in
                              send(2), and the description of TCP_CORK in tcp(7))
    
           SPLICE_F_GIFT      Unused for splice(); see vmsplice(2).
    
    
    

    RETURN VALUE

           Upon successful  completion,  splice()  returns  the  number  of  bytes
           spliced  to or from the pipe.  A return value of 0 means that there was
           no data to transfer, and it would not  make  sense  to  block,  because
           there are no writers connected to the write end of the pipe referred to
           ESPIPE Either  off_in  or  off_out  was not NULL, but the corresponding
                  file descriptor refers to a pipe.
    
    
    

    VERSIONS

           The splice() system call first appeared in Linux 2.6.17;  library  sup-
           port was added to glibc in version 2.5.
    
    
    

    CONFORMING TO

           This system call is Linux-specific.
    
    
    

    NOTES

           The three system calls splice(), vmsplice(2), and tee(2), provide user-
           space programs with full  control  over  an  arbitrary  kernel  buffer,
           implemented  within  the  kernel  using the same type of buffer that is
           used for a pipe.  In overview, these system calls perform the following
           tasks:
    
           splice()    moves data from the buffer to an arbitrary file descriptor,
                       or vice versa, or from one buffer to another.
    
           tee(2)      "copies" the data from one buffer to another.
    
           vmsplice(2) "copies" data from user space into the buffer.
    
           Though we talk of copying, actual copies are  generally  avoided.   The
           kernel  does  this by implementing a pipe buffer as a set of reference-
           counted pointers  to  pages  of  kernel  memory.   The  kernel  creates
           "copies"  of pages in a buffer by creating new pointers (for the output
           buffer) referring to the pages, and increasing the reference counts for
           the pages: only pointers are copied, not the pages of the buffer.
    
    
    

    EXAMPLE

           See tee(2).
    
    
    

    SEE ALSO

           sendfile(2), tee(2), vmsplice(2)
    
    
    

    Linux 2012-05-04 SPLICE(2)

    
    
  • MORE RESOURCE


  • Linux

    The Distributions





    Linux

    The Software





    Linux

    The News



  • MARKETING






  • Toll Free

webmaster@linuxguruz.com
Copyright © 1999 - 2016 by LinuxGuruz