misc/sys/uio.h

   1 /* Copyright (C) 1991,1992,1996-1999,2003,2009,2012
   2    Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _SYS_UIO_H
  20 #define _SYS_UIO_H      1
  21
  22 #include <features.h>
  23
  24 #include <sys/types.h>
  25
  26 __BEGIN_DECLS
  27
  28 /* This file defines `struct iovec'.  */
  29 #include <bits/uio.h>
  30
  31
  32 /* Read data from file descriptor FD, and put the result in the
  33    buffers described by IOVEC, which is a vector of COUNT 'struct iovec's.
  34    The buffers are filled in the order specified.
  35    Operates just like 'read' (see <unistd.h>) except that data are
  36    put in IOVEC instead of a contiguous buffer.
  37
  38    This function is a cancellation point and therefore not marked with
  39    __THROW.  */
  40 extern ssize_t readv (int __fd, const struct iovec *__iovec, int __count)
  41   __wur;
  42
  43 /* Write data pointed by the buffers described by IOVEC, which
  44    is a vector of COUNT 'struct iovec's, to file descriptor FD.
  45    The data is written in the order specified.
  46    Operates just like 'write' (see <unistd.h>) except that the data
  47    are taken from IOVEC instead of a contiguous buffer.
  48
  49    This function is a cancellation point and therefore not marked with
  50    __THROW.  */
  51 extern ssize_t writev (int __fd, const struct iovec *__iovec, int __count)
  52   __wur;
  53
  54
  55 #ifdef __USE_BSD
  56 # ifndef __USE_FILE_OFFSET64
  57 /* Read data from file descriptor FD at the given position OFFSET
  58    without change the file pointer, and put the result in the buffers
  59    described by IOVEC, which is a vector of COUNT 'struct iovec's.
  60    The buffers are filled in the order specified.  Operates just like
  61    'pread' (see <unistd.h>) except that data are put in IOVEC instead
  62    of a contiguous buffer.
  63
  64    This function is a cancellation point and therefore not marked with
  65    __THROW.  */
  66 extern ssize_t preadv (int __fd, const struct iovec *__iovec, int __count,
  67                        __off_t __offset) __wur;
  68
  69 /* Write data pointed by the buffers described by IOVEC, which is a
  70    vector of COUNT 'struct iovec's, to file descriptor FD at the given
  71    position OFFSET without change the file pointer.  The data is
  72    written in the order specified.  Operates just like 'pwrite' (see
  73    <unistd.h>) except that the data are taken from IOVEC instead of a
  74    contiguous buffer.
  75
  76    This function is a cancellation point and therefore not marked with
  77    __THROW.  */
  78 extern ssize_t pwritev (int __fd, const struct iovec *__iovec, int __count,
  79                         __off_t __offset) __wur;
  80 # else
  81 #  ifdef __REDIRECT
  82 extern ssize_t __REDIRECT (preadv, (int __fd, const struct iovec *__iovec,
  83                                     int __count, __off64_t __offset),
  84                            preadv64) __wur;
  85 extern ssize_t __REDIRECT (pwritev, (int __fd, const struct iovec *__iovec,
  86                                      int __count, __off64_t __offset),
  87                            pwritev64) __wur;
  88 #  else
  89 #   define preadv preadv64
  90 #   define pwritev pwritev64
  91 #  endif
  92 # endif
  93
  94 # ifdef __USE_LARGEFILE64
  95 /* Read data from file descriptor FD at the given position OFFSET
  96    without change the file pointer, and put the result in the buffers
  97    described by IOVEC, which is a vector of COUNT 'struct iovec's.
  98    The buffers are filled in the order specified.  Operates just like
  99    'pread' (see <unistd.h>) except that data are put in IOVEC instead
 100    of a contiguous buffer.
 101
 102    This function is a cancellation point and therefore not marked with
 103    __THROW.  */
 104 extern ssize_t preadv64 (int __fd, const struct iovec *__iovec, int __count,
 105                          __off64_t __offset) __wur;
 106
 107 /* Write data pointed by the buffers described by IOVEC, which is a
 108    vector of COUNT 'struct iovec's, to file descriptor FD at the given
 109    position OFFSET without change the file pointer.  The data is
 110    written in the order specified.  Operates just like 'pwrite' (see
 111    <unistd.h>) except that the data are taken from IOVEC instead of a
 112    contiguous buffer.
 113
 114    This function is a cancellation point and therefore not marked with
 115    __THROW.  */
 116 extern ssize_t pwritev64 (int __fd, const struct iovec *__iovec, int __count,
 117                           __off64_t __offset) __wur;
 118 # endif
 119 #endif  /* Use BSD */
 120
 121 __END_DECLS
 122
 123 #endif /* sys/uio.h */