misc/sys/uio.h

   1 /* Copyright (C) 1991-2015 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #ifndef _SYS_UIO_H
  19 #define _SYS_UIO_H      1
  20
  21 #include <features.h>
  22
  23 #include <sys/types.h>
  24
  25 __BEGIN_DECLS
  26
  27 /* This file defines `struct iovec'.  */
  28 #include <bits/uio.h>
  29
  30
  31 /* Read data from file descriptor FD, and put the result in the
  32    buffers described by IOVEC, which is a vector of COUNT 'struct iovec's.
  33    The buffers are filled in the order specified.
  34    Operates just like 'read' (see <unistd.h>) except that data are
  35    put in IOVEC instead of a contiguous buffer.
  36
  37    This function is a cancellation point and therefore not marked with
  38    __THROW.  */
  39 extern ssize_t readv (int __fd, const struct iovec *__iovec, int __count)
  40   __wur;
  41
  42 /* Write data pointed by the buffers described by IOVEC, which
  43    is a vector of COUNT 'struct iovec's, to file descriptor FD.
  44    The data is written in the order specified.
  45    Operates just like 'write' (see <unistd.h>) except that the data
  46    are taken from IOVEC instead of a contiguous buffer.
  47
  48    This function is a cancellation point and therefore not marked with
  49    __THROW.  */
  50 extern ssize_t writev (int __fd, const struct iovec *__iovec, int __count)
  51   __wur;
  52
  53
  54 #ifdef __USE_MISC
  55 # ifndef __USE_FILE_OFFSET64
  56 /* Read data from file descriptor FD at the given position OFFSET
  57    without change the file pointer, and put the result in the buffers
  58    described by IOVEC, which is a vector of COUNT 'struct iovec's.
  59    The buffers are filled in the order specified.  Operates just like
  60    'pread' (see <unistd.h>) except that data are put in IOVEC instead
  61    of a contiguous buffer.
  62
  63    This function is a cancellation point and therefore not marked with
  64    __THROW.  */
  65 extern ssize_t preadv (int __fd, const struct iovec *__iovec, int __count,
  66                        __off_t __offset) __wur;
  67
  68 /* Write data pointed by the buffers described by IOVEC, which is a
  69    vector of COUNT 'struct iovec's, to file descriptor FD at the given
  70    position OFFSET without change the file pointer.  The data is
  71    written in the order specified.  Operates just like 'pwrite' (see
  72    <unistd.h>) except that the data are taken from IOVEC instead of a
  73    contiguous buffer.
  74
  75    This function is a cancellation point and therefore not marked with
  76    __THROW.  */
  77 extern ssize_t pwritev (int __fd, const struct iovec *__iovec, int __count,
  78                         __off_t __offset) __wur;
  79 # else
  80 #  ifdef __REDIRECT
  81 extern ssize_t __REDIRECT (preadv, (int __fd, const struct iovec *__iovec,
  82                                     int __count, __off64_t __offset),
  83                            preadv64) __wur;
  84 extern ssize_t __REDIRECT (pwritev, (int __fd, const struct iovec *__iovec,
  85                                      int __count, __off64_t __offset),
  86                            pwritev64) __wur;
  87 #  else
  88 #   define preadv preadv64
  89 #   define pwritev pwritev64
  90 #  endif
  91 # endif
  92
  93 # ifdef __USE_LARGEFILE64
  94 /* Read data from file descriptor FD at the given position OFFSET
  95    without change the file pointer, and put the result in the buffers
  96    described by IOVEC, which is a vector of COUNT 'struct iovec's.
  97    The buffers are filled in the order specified.  Operates just like
  98    'pread' (see <unistd.h>) except that data are put in IOVEC instead
  99    of a contiguous buffer.
 100
 101    This function is a cancellation point and therefore not marked with
 102    __THROW.  */
 103 extern ssize_t preadv64 (int __fd, const struct iovec *__iovec, int __count,
 104                          __off64_t __offset) __wur;
 105
 106 /* Write data pointed by the buffers described by IOVEC, which is a
 107    vector of COUNT 'struct iovec's, to file descriptor FD at the given
 108    position OFFSET without change the file pointer.  The data is
 109    written in the order specified.  Operates just like 'pwrite' (see
 110    <unistd.h>) except that the data are taken from IOVEC instead of a
 111    contiguous buffer.
 112
 113    This function is a cancellation point and therefore not marked with
 114    __THROW.  */
 115 extern ssize_t pwritev64 (int __fd, const struct iovec *__iovec, int __count,
 116                           __off64_t __offset) __wur;
 117 # endif
 118 #endif  /* Use misc.  */
 119
 120 __END_DECLS
 121
 122 #endif /* sys/uio.h */