misc/sys/uio.h

   1 /* Copyright (C) 1991-2018 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 #include <sys/types.h>
  23 #include <bits/types/struct_iovec.h>
  24 #include <bits/uio_lim.h>
  25 #ifdef __IOV_MAX
  26 # define UIO_MAXIOV __IOV_MAX
  27 #else
  28 # undef UIO_MAXIOV
  29 #endif
  30
  31 __BEGIN_DECLS
  32
  33 /* Read data from file descriptor FD, and put the result in the
  34    buffers described by IOVEC, which is a vector of COUNT 'struct iovec's.
  35    The buffers are filled in the order specified.
  36    Operates just like 'read' (see <unistd.h>) except that data are
  37    put in IOVEC instead of a contiguous buffer.
  38
  39    This function is a cancellation point and therefore not marked with
  40    __THROW.  */
  41 extern ssize_t readv (int __fd, const struct iovec *__iovec, int __count)
  42   __wur;
  43
  44 /* Write data pointed by the buffers described by IOVEC, which
  45    is a vector of COUNT 'struct iovec's, to file descriptor FD.
  46    The data is written in the order specified.
  47    Operates just like 'write' (see <unistd.h>) except that the data
  48    are taken from IOVEC instead of a contiguous buffer.
  49
  50    This function is a cancellation point and therefore not marked with
  51    __THROW.  */
  52 extern ssize_t writev (int __fd, const struct iovec *__iovec, int __count)
  53   __wur;
  54
  55
  56 #ifdef __USE_MISC
  57 # ifndef __USE_FILE_OFFSET64
  58 /* Read data from file descriptor FD at the given position OFFSET
  59    without change the file pointer, and put the result in the buffers
  60    described by IOVEC, which is a vector of COUNT 'struct iovec's.
  61    The buffers are filled in the order specified.  Operates just like
  62    'pread' (see <unistd.h>) except that data are put in IOVEC instead
  63    of a contiguous buffer.
  64
  65    This function is a cancellation point and therefore not marked with
  66    __THROW.  */
  67 extern ssize_t preadv (int __fd, const struct iovec *__iovec, int __count,
  68                        __off_t __offset) __wur;
  69
  70 /* Write data pointed by the buffers described by IOVEC, which is a
  71    vector of COUNT 'struct iovec's, to file descriptor FD at the given
  72    position OFFSET without change the file pointer.  The data is
  73    written in the order specified.  Operates just like 'pwrite' (see
  74    <unistd.h>) except that the data are taken from IOVEC instead of a
  75    contiguous buffer.
  76
  77    This function is a cancellation point and therefore not marked with
  78    __THROW.  */
  79 extern ssize_t pwritev (int __fd, const struct iovec *__iovec, int __count,
  80                         __off_t __offset) __wur;
  81
  82 # else
  83 #  ifdef __REDIRECT
  84 extern ssize_t __REDIRECT (preadv, (int __fd, const struct iovec *__iovec,
  85                                     int __count, __off64_t __offset),
  86                            preadv64) __wur;
  87 extern ssize_t __REDIRECT (pwritev, (int __fd, const struct iovec *__iovec,
  88                                      int __count, __off64_t __offset),
  89                            pwritev64) __wur;
  90 #  else
  91 #   define preadv preadv64
  92 #   define pwritev pwritev64
  93 #  endif
  94 # endif
  95
  96 # ifdef __USE_LARGEFILE64
  97 /* Read data from file descriptor FD at the given position OFFSET
  98    without change the file pointer, and put the result in the buffers
  99    described by IOVEC, which is a vector of COUNT 'struct iovec's.
 100    The buffers are filled in the order specified.  Operates just like
 101    'pread' (see <unistd.h>) except that data are put in IOVEC instead
 102    of a contiguous buffer.
 103
 104    This function is a cancellation point and therefore not marked with
 105    __THROW.  */
 106 extern ssize_t preadv64 (int __fd, const struct iovec *__iovec, int __count,
 107                          __off64_t __offset) __wur;
 108
 109 /* Write data pointed by the buffers described by IOVEC, which is a
 110    vector of COUNT 'struct iovec's, to file descriptor FD at the given
 111    position OFFSET without change the file pointer.  The data is
 112    written in the order specified.  Operates just like 'pwrite' (see
 113    <unistd.h>) except that the data are taken from IOVEC instead of a
 114    contiguous buffer.
 115
 116    This function is a cancellation point and therefore not marked with
 117    __THROW.  */
 118 extern ssize_t pwritev64 (int __fd, const struct iovec *__iovec, int __count,
 119                           __off64_t __offset) __wur;
 120 # endif
 121 #endif  /* Use misc.  */
 122
 123
 124 #ifdef __USE_GNU
 125 # ifndef __USE_FILE_OFFSET64
 126 /* Same as preadv but with an additional flag argumenti defined at uio.h.  */
 127 extern ssize_t preadv2 (int __fp, const struct iovec *__iovec, int __count,
 128                         __off_t __offset, int ___flags) __wur;
 129
 130 /* Same as preadv but with an additional flag argument defined at uio.h.  */
 131 extern ssize_t pwritev2 (int __fd, const struct iovec *__iodev, int __count,
 132                          __off_t __offset, int __flags) __wur;
 133
 134 # else
 135 #  ifdef __REDIRECT
 136 extern ssize_t __REDIRECT (pwritev2, (int __fd, const struct iovec *__iovec,
 137                                       int __count, __off64_t __offset,
 138                                       int __flags),
 139                            pwritev64v2) __wur;
 140 extern ssize_t __REDIRECT (preadv2, (int __fd, const struct iovec *__iovec,
 141                                      int __count, __off64_t __offset,
 142                                      int __flags),
 143                            preadv64v2) __wur;
 144 #  else
 145 #   define preadv2 preadv64v2
 146 #   define pwritev2 pwritev64v2
 147 #  endif
 148 # endif
 149
 150 # ifdef __USE_LARGEFILE64
 151 /* Same as preadv but with an additional flag argumenti defined at uio.h.  */
 152 extern ssize_t preadv64v2 (int __fp, const struct iovec *__iovec,
 153                            int __count, __off64_t __offset,
 154                            int ___flags) __wur;
 155
 156 /* Same as preadv but with an additional flag argument defined at uio.h.  */
 157 extern ssize_t pwritev64v2 (int __fd, const struct iovec *__iodev,
 158                             int __count, __off64_t __offset,
 159                             int __flags) __wur;
 160 # endif
 161 #endif /* Use GNU.  */
 162
 163 __END_DECLS
 164
 165 /* Some operating systems provide system-specific extensions to this
 166    header.  */
 167 #ifdef __USE_GNU
 168 # include <bits/uio-ext.h>
 169 #endif
 170
 171 #endif /* sys/uio.h */