| 1 | /* Work around a bug of lstat on some systems
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| 2 |
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| 3 | Copyright (C) 1997-2006, 2008-2012 Free Software Foundation, Inc.
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| 4 |
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| 5 | This program is free software: you can redistribute it and/or modify
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| 6 | it under the terms of the GNU General Public License as published by
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| 7 | the Free Software Foundation; either version 3 of the License, or
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| 8 | (at your option) any later version.
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| 9 |
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| 10 | This program is distributed in the hope that it will be useful,
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| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of
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| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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| 13 | GNU General Public License for more details.
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| 14 |
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| 15 | You should have received a copy of the GNU General Public License
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| 16 | along with this program. If not, see <http://www.gnu.org/licenses/>. */
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| 17 |
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| 18 | /* written by Jim Meyering */
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| 19 |
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| 20 | /* If the user's config.h happens to include <sys/stat.h>, let it include only
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| 21 | the system's <sys/stat.h> here, so that orig_lstat doesn't recurse to
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| 22 | rpl_lstat. */
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| 23 | #define __need_system_sys_stat_h
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| 24 | #include <config.h>
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| 25 |
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| 26 | #if !HAVE_LSTAT
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| 27 | /* On systems that lack symlinks, our replacement <sys/stat.h> already
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| 28 | defined lstat as stat, so there is nothing further to do other than
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| 29 | avoid an empty file. */
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| 30 | typedef int dummy;
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| 31 | #else /* HAVE_LSTAT */
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| 32 |
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| 33 | /* Get the original definition of lstat. It might be defined as a macro. */
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| 34 | # include <sys/types.h>
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| 35 | # include <sys/stat.h>
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| 36 | # undef __need_system_sys_stat_h
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| 37 |
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| 38 | static inline int
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| 39 | orig_lstat (const char *filename, struct stat *buf)
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| 40 | {
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| 41 | return lstat (filename, buf);
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| 42 | }
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| 43 |
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| 44 | /* Specification. */
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| 45 | /* Write "sys/stat.h" here, not <sys/stat.h>, otherwise OSF/1 5.1 DTK cc
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| 46 | eliminates this include because of the preliminary #include <sys/stat.h>
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| 47 | above. */
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| 48 | # include "sys/stat.h"
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| 49 |
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| 50 | # include <string.h>
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| 51 | # include <errno.h>
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| 52 |
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| 53 | /* lstat works differently on Linux and Solaris systems. POSIX (see
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| 54 | "pathname resolution" in the glossary) requires that programs like
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| 55 | 'ls' take into consideration the fact that FILE has a trailing slash
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| 56 | when FILE is a symbolic link. On Linux and Solaris 10 systems, the
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| 57 | lstat function already has the desired semantics (in treating
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| 58 | 'lstat ("symlink/", sbuf)' just like 'lstat ("symlink/.", sbuf)',
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| 59 | but on Solaris 9 and earlier it does not.
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| 60 |
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| 61 | If FILE has a trailing slash and specifies a symbolic link,
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| 62 | then use stat() to get more info on the referent of FILE.
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| 63 | If the referent is a non-directory, then set errno to ENOTDIR
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| 64 | and return -1. Otherwise, return stat's result. */
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| 65 |
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| 66 | int
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| 67 | rpl_lstat (const char *file, struct stat *sbuf)
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| 68 | {
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| 69 | size_t len;
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| 70 | int lstat_result = orig_lstat (file, sbuf);
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| 71 |
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| 72 | if (lstat_result != 0)
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| 73 | return lstat_result;
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| 74 |
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| 75 | /* This replacement file can blindly check against '/' rather than
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| 76 | using the ISSLASH macro, because all platforms with '\\' either
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| 77 | lack symlinks (mingw) or have working lstat (cygwin) and thus do
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| 78 | not compile this file. 0 len should have already been filtered
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| 79 | out above, with a failure return of ENOENT. */
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| 80 | len = strlen (file);
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| 81 | if (file[len - 1] != '/' || S_ISDIR (sbuf->st_mode))
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| 82 | return 0;
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| 83 |
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| 84 | /* At this point, a trailing slash is only permitted on
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| 85 | symlink-to-dir; but it should have found information on the
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| 86 | directory, not the symlink. Call stat() to get info about the
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| 87 | link's referent. Our replacement stat guarantees valid results,
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| 88 | even if the symlink is not pointing to a directory. */
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| 89 | if (!S_ISLNK (sbuf->st_mode))
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| 90 | {
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| 91 | errno = ENOTDIR;
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| 92 | return -1;
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| 93 | }
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| 94 | return stat (file, sbuf);
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| 95 | }
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| 96 |
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| 97 | #endif /* HAVE_LSTAT */
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