glibc/posix/pread.c

45 lines
1.3 KiB
C

/* Copyright (C) 1991-2020 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
<https://www.gnu.org/licenses/>. */
#include <errno.h>
#include <unistd.h>
/* Read NBYTES into BUF from FD at the given position OFFSET without
changing the file pointer. Return the number read or -1. */
ssize_t
__libc_pread (int fd, void *buf, size_t nbytes, off_t offset)
{
if (nbytes == 0)
return 0;
if (fd < 0)
{
__set_errno (EBADF);
return -1;
}
if (buf == NULL || offset < 0)
{
__set_errno (EINVAL);
return -1;
}
__set_errno (ENOSYS);
return -1;
}
strong_alias (__libc_pread, __pread)
weak_alias (__libc_pread, pread)
stub_warning (pread)