glibc/sysdeps/posix/truncate.c

45 lines
1.3 KiB
C

/* Truncate a file given by name. Generic POSIX.1 version.
Copyright (C) 1995-2016 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 <sys/types.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
/* Truncate PATH to LENGTH bytes. */
int
__truncate (const char *path, off_t length)
{
int fd, ret, save;
fd = __open (path, O_WRONLY | (length == 0 ? O_TRUNC : 0));
if (fd < 0)
return -1;
if (length == 0)
ret = 0;
else
ret = __ftruncate (fd, length);
save = errno;
(void) __close (fd);
if (ret < 0)
__set_errno (save);
return ret;
}
weak_alias (__truncate, truncate)