readlink.c revision 7c2fbfb345896881c631598ee3852ce9ce33fb07
/***********************************************************************
* *
* This software is part of the ast package *
* Copyright (c) 1985-2008 AT&T Intellectual Property *
* and is licensed under the *
* Common Public License, Version 1.0 *
* by AT&T Intellectual Property *
* *
* A copy of the License is available at *
* http://www.opensource.org/licenses/cpl1.0.txt *
* (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) *
* *
* Information and Software Systems Research *
* AT&T Research *
* Florham Park NJ *
* *
* Glenn Fowler <gsf@research.att.com> *
* David Korn <dgk@research.att.com> *
* Phong Vo <kpv@research.att.com> *
* *
***********************************************************************/
#pragma prototyped
#include <ast.h>
#if _lib_readlink
NoN(readlink)
#else
#include "fakelink.h"
#include <error.h>
#ifndef ENOSYS
#define ENOSYS EINVAL
#endif
int
readlink(const char* path, char* buf, int siz)
{
int fd;
int n;
if (siz > sizeof(FAKELINK_MAGIC))
{
if ((fd = open(path, O_RDONLY)) < 0)
return -1;
if (read(fd, buf, sizeof(FAKELINK_MAGIC)) == sizeof(FAKELINK_MAGIC) && !strcmp(buf, FAKELINK_MAGIC) && (n = read(fd, buf, siz)) > 0 && !buf[n - 1])
{
close(fd);
return n;
}
close(fd);
}
errno = ENOSYS;
return -1;
}
#endif