1/* Work around a bug of lstat on some systems 2 3 Copyright (C) 1997-2006, 2008-2014 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/* If the user's config.h happens to include <sys/stat.h>, let it include only 21 the system's <sys/stat.h> here, so that orig_lstat doesn't recurse to 22 rpl_lstat. */ 23#define __need_system_sys_stat_h 24#include <config.h> 25 26#if !HAVE_LSTAT 27/* On systems that lack symlinks, our replacement <sys/stat.h> already 28 defined lstat as stat, so there is nothing further to do other than 29 avoid an empty file. */ 30typedef int dummy; 31#else /* HAVE_LSTAT */ 32 33/* Get the original definition of lstat. It might be defined as a macro. */ 34# include <sys/types.h> 35# include <sys/stat.h> 36# undef __need_system_sys_stat_h 37 38static int 39orig_lstat (const char *filename, struct stat *buf) 40{ 41 return lstat (filename, buf); 42} 43 44/* Specification. */ 45/* Write "sys/stat.h" here, not <sys/stat.h>, otherwise OSF/1 5.1 DTK cc 46 eliminates this include because of the preliminary #include <sys/stat.h> 47 above. */ 48# include "sys/stat.h" 49 50# include <string.h> 51# include <errno.h> 52 53/* lstat works differently on Linux and Solaris systems. POSIX (see 54 "pathname resolution" in the glossary) requires that programs like 55 'ls' take into consideration the fact that FILE has a trailing slash 56 when FILE is a symbolic link. On Linux and Solaris 10 systems, the 57 lstat function already has the desired semantics (in treating 58 'lstat ("symlink/", sbuf)' just like 'lstat ("symlink/.", sbuf)', 59 but on Solaris 9 and earlier it does not. 60 61 If FILE has a trailing slash and specifies a symbolic link, 62 then use stat() to get more info on the referent of FILE. 63 If the referent is a non-directory, then set errno to ENOTDIR 64 and return -1. Otherwise, return stat's result. */ 65 66int 67rpl_lstat (const char *file, struct stat *sbuf) 68{ 69 size_t len; 70 int lstat_result = orig_lstat (file, sbuf); 71 72 if (lstat_result != 0) 73 return lstat_result; 74 75 /* This replacement file can blindly check against '/' rather than 76 using the ISSLASH macro, because all platforms with '\\' either 77 lack symlinks (mingw) or have working lstat (cygwin) and thus do 78 not compile this file. 0 len should have already been filtered 79 out above, with a failure return of ENOENT. */ 80 len = strlen (file); 81 if (file[len - 1] != '/' || S_ISDIR (sbuf->st_mode)) 82 return 0; 83 84 /* At this point, a trailing slash is only permitted on 85 symlink-to-dir; but it should have found information on the 86 directory, not the symlink. Call stat() to get info about the 87 link's referent. Our replacement stat guarantees valid results, 88 even if the symlink is not pointing to a directory. */ 89 if (!S_ISLNK (sbuf->st_mode)) 90 { 91 errno = ENOTDIR; 92 return -1; 93 } 94 return stat (file, sbuf); 95} 96 97#endif /* HAVE_LSTAT */ 98