1 /* An interface to read and write that retries after interrupts.
2 Copyright (C) 1993, 1994, 1998, 2002-2003 Free Software Foundation, Inc.
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2, or (at your option)
9 This program 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
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software Foundation,
16 Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
24 # include "safe-write.h"
26 # include "safe-read.h"
30 #include <sys/types.h>
41 # define IS_EINTR(x) ((x) == EINTR)
43 # define IS_EINTR(x) 0
49 # define safe_rw safe_write
52 # define safe_rw safe_read
55 # define const /* empty */
58 /* Read(write) up to COUNT bytes at BUF from(to) descriptor FD, retrying if
59 interrupted. Return the actual number of bytes read(written), zero for EOF,
60 or SAFE_READ_ERROR(SAFE_WRITE_ERROR) upon error. */
62 safe_rw (int fd, void const *buf, size_t count)
66 /* POSIX limits COUNT to SSIZE_MAX, but we limit it further, requiring
67 that COUNT <= INT_MAX, to avoid triggering a bug in Tru64 5.1.
68 When decreasing COUNT, keep the file pointer block-aligned.
69 Note that in any case, read(write) may succeed, yet read(write)
70 fewer than COUNT bytes, so the caller must be prepared to handle
73 count = INT_MAX & ~8191;
77 result = rw (fd, buf, count);
79 while (result < 0 && IS_EINTR (errno));
81 return (size_t) result;