glibc/sysdeps/unix/sysv/linux/futimesat.c
2014-02-10 15:07:12 +01:00

140 lines
3.7 KiB
C

/* Copyright (C) 2005-2014 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C 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 2.1 of the License, or (at your option) any later version.
The GNU C 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 the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <fcntl.h>
#include <stddef.h>
#include <stdio.h>
#include <string.h>
#include <utime.h>
#include <sys/time.h>
#include <sysdep.h>
#include <kernel-features.h>
/* Change the access time of FILE relative to FD to TVP[0] and
the modification time of FILE to TVP[1]. */
int
futimesat (fd, file, tvp)
int fd;
const char *file;
const struct timeval tvp[2];
{
int result;
#ifdef __NR_futimesat
# ifndef __ASSUME_ATFCTS
if (__have_atfcts >= 0)
# endif
{
if (file == NULL)
return __futimes (fd, tvp);
result = INLINE_SYSCALL (futimesat, 3, fd, file, tvp);
# ifndef __ASSUME_ATFCTS
if (result == -1 && errno == ENOSYS)
__have_atfcts = -1;
else
# endif
return result;
}
#endif
#ifndef __ASSUME_ATFCTS
char *buf = NULL;
if (file == NULL)
{
static const char procfd[] = "/proc/self/fd/%d";
/* Buffer for the path name we are going to use. It consists of
- the string /proc/self/fd/
- the file descriptor number.
The final NUL is included in the sizeof. A bit of overhead
due to the format elements compensates for possible negative
numbers. */
size_t buflen = sizeof (procfd) + sizeof (int) * 3;
buf = alloca (buflen);
__snprintf (buf, buflen, procfd, fd);
file = buf;
}
else if (fd != AT_FDCWD && file[0] != '/')
{
size_t filelen = strlen (file);
if (__glibc_unlikely (filelen == 0))
{
__set_errno (ENOENT);
return -1;
}
static const char procfd[] = "/proc/self/fd/%d/%s";
/* Buffer for the path name we are going to use. It consists of
- the string /proc/self/fd/
- the file descriptor number
- the file name provided.
The final NUL is included in the sizeof. A bit of overhead
due to the format elements compensates for possible negative
numbers. */
size_t buflen = sizeof (procfd) + sizeof (int) * 3 + filelen;
buf = alloca (buflen);
__snprintf (buf, buflen, procfd, fd, file);
file = buf;
}
INTERNAL_SYSCALL_DECL (err);
# ifdef __NR_utimes
result = INTERNAL_SYSCALL (utimes, err, 2, file, tvp);
if (__glibc_likely (!INTERNAL_SYSCALL_ERROR_P (result, err)))
return result;
# ifndef __ASSUME_UTIMES
if (INTERNAL_SYSCALL_ERRNO (result, err) != ENOSYS)
goto fail;
# endif
# endif
/* The utimes() syscall does not exist or is not available in the
used kernel. Use utime(). For this we have to convert to the
data format utime() expects. */
# ifndef __ASSUME_UTIMES
struct utimbuf tmp;
struct utimbuf *times;
if (tvp != NULL)
{
times = &tmp;
tmp.actime = tvp[0].tv_sec + tvp[0].tv_usec / 1000000;
tmp.modtime = tvp[1].tv_sec + tvp[1].tv_usec / 1000000;
}
else
times = NULL;
result = INTERNAL_SYSCALL (utime, err, 2, file, times);
if (__glibc_likely (!INTERNAL_SYSCALL_ERROR_P (result, err)))
return result;
fail:
# endif
__atfct_seterrno (INTERNAL_SYSCALL_ERRNO (result, err), fd, buf);
return -1;
#endif
}