1 /*********************************************************************** 2 * * 3 * This software is part of the ast package * 4 * Copyright (c) 1985-2007 AT&T Knowledge Ventures * 5 * and is licensed under the * 6 * Common Public License, Version 1.0 * 7 * by AT&T Knowledge Ventures * 8 * * 9 * A copy of the License is available at * 10 * http://www.opensource.org/licenses/cpl1.0.txt * 11 * (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) * 12 * * 13 * Information and Software Systems Research * 14 * AT&T Research * 15 * Florham Park NJ * 16 * * 17 * Glenn Fowler <gsf@research.att.com> * 18 * David Korn <dgk@research.att.com> * 19 * Phong Vo <kpv@research.att.com> * 20 * * 21 ***********************************************************************/ 22 #pragma prototyped 23 24 #include <ast.h> 25 26 #if _lib_readlink 27 28 NoN(readlink) 29 30 #else 31 32 #include "fakelink.h" 33 34 #include <error.h> 35 36 #ifndef ENOSYS 37 #define ENOSYS EINVAL 38 #endif 39 40 int 41 readlink(const char* path, char* buf, int siz) 42 { 43 int fd; 44 int n; 45 46 if (siz > sizeof(FAKELINK_MAGIC)) 47 { 48 if ((fd = open(path, O_RDONLY)) < 0) 49 return -1; 50 if (read(fd, buf, sizeof(FAKELINK_MAGIC)) == sizeof(FAKELINK_MAGIC) && !strcmp(buf, FAKELINK_MAGIC) && (n = read(fd, buf, siz)) > 0 && !buf[n - 1]) 51 { 52 close(fd); 53 return n; 54 } 55 close(fd); 56 } 57 errno = ENOSYS; 58 return -1; 59 } 60 61 #endif 62