From 82d1989d3245791c9fac22ca848f5497f261c10b Mon Sep 17 00:00:00 2001 From: Ton Voon Date: Wed, 15 Dec 2004 20:47:26 +0000 Subject: Moving m4 files into m4/. Added extra coreutils files required from autoconf tests. Updated Makefile.am to have nagiosplug lib and a separate coreutils lib git-svn-id: https://nagiosplug.svn.sourceforge.net/svnroot/nagiosplug/nagiosplug/trunk@1027 f882894a-f735-0410-b71e-b25c423dba1c --- lib/safe-read.c | 82 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 82 insertions(+) create mode 100644 lib/safe-read.c (limited to 'lib/safe-read.c') diff --git a/lib/safe-read.c b/lib/safe-read.c new file mode 100644 index 00000000..c21d1cf1 --- /dev/null +++ b/lib/safe-read.c @@ -0,0 +1,82 @@ +/* An interface to read and write that retries after interrupts. + Copyright (C) 1993, 1994, 1998, 2002-2003 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2, or (at your option) + any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software Foundation, + Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ + +#if HAVE_CONFIG_H +# include +#endif + +/* Specification. */ +#ifdef SAFE_WRITE +# include "safe-write.h" +#else +# include "safe-read.h" +#endif + +/* Get ssize_t. */ +#include +#if HAVE_UNISTD_H +# include +#endif + +#include +#ifndef errno +extern int errno; +#endif + +#ifdef EINTR +# define IS_EINTR(x) ((x) == EINTR) +#else +# define IS_EINTR(x) 0 +#endif + +#include + +#ifdef SAFE_WRITE +# define safe_rw safe_write +# define rw write +#else +# define safe_rw safe_read +# define rw read +# undef const +# define const /* empty */ +#endif + +/* Read(write) up to COUNT bytes at BUF from(to) descriptor FD, retrying if + interrupted. Return the actual number of bytes read(written), zero for EOF, + or SAFE_READ_ERROR(SAFE_WRITE_ERROR) upon error. */ +size_t +safe_rw (int fd, void const *buf, size_t count) +{ + ssize_t result; + + /* POSIX limits COUNT to SSIZE_MAX, but we limit it further, requiring + that COUNT <= INT_MAX, to avoid triggering a bug in Tru64 5.1. + When decreasing COUNT, keep the file pointer block-aligned. + Note that in any case, read(write) may succeed, yet read(write) + fewer than COUNT bytes, so the caller must be prepared to handle + partial results. */ + if (count > INT_MAX) + count = INT_MAX & ~8191; + + do + { + result = rw (fd, buf, count); + } + while (result < 0 && IS_EINTR (errno)); + + return (size_t) result; +} -- cgit v1.2.3-74-g34f1