Files
libguestfs/gnulib/lib/safe-read.c
Richard W.M. Jones e2c7bddf10 Update copyright dates for 2023
Run this command across the source:

  perl -pi.bak -e 's/(20[012][0-9])-20[12][012]/$1-2023/g' `git ls-files`

and remove changes to po{,-docs}/*.po{,t} (these will be regenerated
later when we run 'make dist').
2023-02-07 10:50:48 +00:00

80 lines
2.2 KiB
C

/* An interface to read and write that retries after interrupts.
Copyright (C) 1993-1994, 1998, 2002-2006, 2009-2023 Free Software
Foundation, Inc.
(NB: I modified the original GPL boilerplate here to LGPLv2+. This
is because of the weird way that gnulib uses licenses, where the
real license is covered in the modules/X file. The real license
for this file is LGPLv2+, not GPL. - RWMJ)
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <config.h>
/* Specification. */
#ifdef SAFE_WRITE
# include "safe-write.h"
#else
# include "safe-read.h"
#endif
/* Get ssize_t. */
#include <sys/types.h>
#include <unistd.h>
#include <limits.h>
#include <errno.h>
#ifdef EINTR
# define IS_EINTR(x) ((x) == EINTR)
#else
# define IS_EINTR(x) 0
#endif
enum { SYS_BUFSIZE_MAX = INT_MAX >> 20 << 20 };
#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)
{
for (;;)
{
ssize_t result = rw (fd, buf, count);
if (0 <= result)
return result;
else if (IS_EINTR (errno))
continue;
else if (errno == EINVAL && SYS_BUFSIZE_MAX < count)
count = SYS_BUFSIZE_MAX;
else
return result;
}
}