glibc/sysdeps/mach/hurd/readlink.c
2012-02-09 23:18:22 +00:00

65 lines
1.8 KiB
C

/* Copyright (C) 1991,92,93,94,95,97,2002 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 <unistd.h>
#include <hurd.h>
#include <hurd/paths.h>
#include <fcntl.h>
#include <string.h>
/* Read the contents of the symbolic link FILE_NAME into no more than
LEN bytes of BUF. The contents are not null-terminated.
Returns the number of characters read, or -1 for errors. */
ssize_t
__readlink (file_name, buf, len)
const char *file_name;
char *buf;
size_t len;
{
error_t err;
file_t file;
struct stat64 st;
file = __file_name_lookup (file_name, O_READ | O_NOLINK, 0);
if (file == MACH_PORT_NULL)
return -1;
err = __io_stat (file, &st);
if (! err)
if (S_ISLNK (st.st_mode))
{
char *rbuf = buf;
err = __io_read (file, &rbuf, &len, 0, len);
if (!err && rbuf != buf)
{
memcpy (buf, rbuf, len);
__vm_deallocate (__mach_task_self (), (vm_address_t)rbuf, len);
}
}
else
err = EINVAL;
__mach_port_deallocate (__mach_task_self (), file);
if (err)
return __hurd_fail (err);
else
return len;
}
weak_alias (__readlink, readlink)