1/* Work around a bug of lstat on some systems 2 3 Copyright (C) 1997-2006, 2008-2011 Free Software Foundation, Inc. 4 5 This program is free software: you can redistribute it and/or modify 6 it under the terms of the GNU General Public License as published by 7 the Free Software Foundation; either version 3 of the License, or 8 (at your option) any later version. 9 10 This program is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 GNU General Public License for more details. 14 15 You should have received a copy of the GNU General Public License 16 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 17 18/* written by Jim Meyering */ 19 20#include <config.h> 21 22#if !HAVE_LSTAT 23/* On systems that lack symlinks, our replacement <sys/stat.h> already 24 defined lstat as stat, so there is nothing further to do other than 25 avoid an empty file. */ 26typedef int dummy; 27#else /* HAVE_LSTAT */ 28 29/* Get the original definition of lstat. It might be defined as a macro. */ 30# define __need_system_sys_stat_h 31# include <sys/types.h> 32# include <sys/stat.h> 33# undef __need_system_sys_stat_h 34 35static inline int 36orig_lstat (const char *filename, struct stat *buf) 37{ 38 return lstat (filename, buf); 39} 40 41/* Specification. */ 42# include <sys/stat.h> 43 44# include <string.h> 45# include <errno.h> 46 47/* lstat works differently on Linux and Solaris systems. POSIX (see 48 `pathname resolution' in the glossary) requires that programs like 49 `ls' take into consideration the fact that FILE has a trailing slash 50 when FILE is a symbolic link. On Linux and Solaris 10 systems, the 51 lstat function already has the desired semantics (in treating 52 `lstat ("symlink/", sbuf)' just like `lstat ("symlink/.", sbuf)', 53 but on Solaris 9 and earlier it does not. 54 55 If FILE has a trailing slash and specifies a symbolic link, 56 then use stat() to get more info on the referent of FILE. 57 If the referent is a non-directory, then set errno to ENOTDIR 58 and return -1. Otherwise, return stat's result. */ 59 60int 61rpl_lstat (const char *file, struct stat *sbuf) 62{ 63 size_t len; 64 int lstat_result = orig_lstat (file, sbuf); 65 66 if (lstat_result != 0) 67 return lstat_result; 68 69 /* This replacement file can blindly check against '/' rather than 70 using the ISSLASH macro, because all platforms with '\\' either 71 lack symlinks (mingw) or have working lstat (cygwin) and thus do 72 not compile this file. 0 len should have already been filtered 73 out above, with a failure return of ENOENT. */ 74 len = strlen (file); 75 if (file[len - 1] != '/' || S_ISDIR (sbuf->st_mode)) 76 return 0; 77 78 /* At this point, a trailing slash is only permitted on 79 symlink-to-dir; but it should have found information on the 80 directory, not the symlink. Call stat() to get info about the 81 link's referent. Our replacement stat guarantees valid results, 82 even if the symlink is not pointing to a directory. */ 83 if (!S_ISLNK (sbuf->st_mode)) 84 { 85 errno = ENOTDIR; 86 return -1; 87 } 88 return stat (file, sbuf); 89} 90 91#endif /* HAVE_LSTAT */ 92