1 /* An interface to read and write that retries (if necessary) until complete.
3 Copyright (C) 1993, 1994, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
4 2004, 2005, 2006 Free Software Foundation, Inc.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software Foundation,
18 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
24 # include "full-read.h"
26 # include "full-write.h"
32 # include "safe-read.h"
33 # define safe_rw safe_read
34 # define full_rw full_read
36 # define const /* empty */
38 # include "safe-write.h"
39 # define safe_rw safe_write
40 # define full_rw full_write
44 /* Set errno to zero upon EOF. */
45 # define ZERO_BYTE_TRANSFER_ERRNO 0
47 /* Some buggy drivers return 0 when one tries to write beyond
48 a device's end. (Example: Linux 1.2.13 on /dev/fd0.)
49 Set errno to ENOSPC so they get a sensible diagnostic. */
50 # define ZERO_BYTE_TRANSFER_ERRNO ENOSPC
53 /* Write(read) COUNT bytes at BUF to(from) descriptor FD, retrying if
54 interrupted or if a partial write(read) occurs. Return the number
56 When writing, set errno if fewer than COUNT bytes are written.
57 When reading, if fewer than COUNT bytes are read, you must examine
58 errno to distinguish failure from EOF (errno == 0). */
60 full_rw (int fd
, const void *buf
, size_t count
)
63 const char *ptr
= (const char *) buf
;
67 size_t n_rw
= safe_rw (fd
, ptr
, count
);
68 if (n_rw
== (size_t) -1)
72 errno
= ZERO_BYTE_TRANSFER_ERRNO
;