| 1 | /* Stub for readlink(). |
| 2 | Copyright (C) 2003-2007, 2009-2014 Free Software Foundation, Inc. |
| 3 | |
| 4 | This program is free software: you can redistribute it and/or modify |
| 5 | it under the terms of the GNU Lesser General Public License as published by |
| 6 | the Free Software Foundation; either version 3 of the License, or |
| 7 | (at your option) any later version. |
| 8 | |
| 9 | This program is distributed in the hope that it will be useful, |
| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | GNU Lesser General Public License for more details. |
| 13 | |
| 14 | You should have received a copy of the GNU Lesser General Public License |
| 15 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 16 | |
| 17 | #include <config.h> |
| 18 | |
| 19 | /* Specification. */ |
| 20 | #include <unistd.h> |
| 21 | |
| 22 | #include <errno.h> |
| 23 | #include <string.h> |
| 24 | #include <sys/stat.h> |
| 25 | |
| 26 | #if !HAVE_READLINK |
| 27 | |
| 28 | /* readlink() substitute for systems that don't have a readlink() function, |
| 29 | such as DJGPP 2.03 and mingw32. */ |
| 30 | |
| 31 | ssize_t |
| 32 | readlink (const char *name, char *buf _GL_UNUSED, |
| 33 | size_t bufsize _GL_UNUSED) |
| 34 | { |
| 35 | struct stat statbuf; |
| 36 | |
| 37 | /* In general we should use lstat() here, not stat(). But on platforms |
| 38 | without symbolic links, lstat() - if it exists - would be equivalent to |
| 39 | stat(), therefore we can use stat(). This saves us a configure check. */ |
| 40 | if (stat (name, &statbuf) >= 0) |
| 41 | errno = EINVAL; |
| 42 | return -1; |
| 43 | } |
| 44 | |
| 45 | #else /* HAVE_READLINK */ |
| 46 | |
| 47 | # undef readlink |
| 48 | |
| 49 | /* readlink() wrapper that uses correct types, for systems like cygwin |
| 50 | 1.5.x where readlink returns int, and which rejects trailing slash, |
| 51 | for Solaris 9. */ |
| 52 | |
| 53 | ssize_t |
| 54 | rpl_readlink (const char *name, char *buf, size_t bufsize) |
| 55 | { |
| 56 | # if READLINK_TRAILING_SLASH_BUG |
| 57 | size_t len = strlen (name); |
| 58 | if (len && name[len - 1] == '/') |
| 59 | { |
| 60 | /* Even if name without the slash is a symlink to a directory, |
| 61 | both lstat() and stat() must resolve the trailing slash to |
| 62 | the directory rather than the symlink. We can therefore |
| 63 | safely use stat() to distinguish between EINVAL and |
| 64 | ENOTDIR/ENOENT, avoiding extra overhead of rpl_lstat(). */ |
| 65 | struct stat st; |
| 66 | if (stat (name, &st) == 0) |
| 67 | errno = EINVAL; |
| 68 | return -1; |
| 69 | } |
| 70 | # endif /* READLINK_TRAILING_SLASH_BUG */ |
| 71 | return readlink (name, buf, bufsize); |
| 72 | } |
| 73 | |
| 74 | #endif /* HAVE_READLINK */ |