diff options
Diffstat (limited to 'gl/lib/readlink.c')
-rw-r--r-- | gl/lib/readlink.c | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/gl/lib/readlink.c b/gl/lib/readlink.c new file mode 100644 index 0000000..bf71109 --- /dev/null +++ b/gl/lib/readlink.c @@ -0,0 +1,74 @@ +/* Stub for readlink(). + Copyright (C) 2003-2007, 2009-2019 Free Software Foundation, Inc. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. */ + +#include <config.h> + +/* Specification. */ +#include <unistd.h> + +#include <errno.h> +#include <string.h> +#include <sys/stat.h> + +#if !HAVE_READLINK + +/* readlink() substitute for systems that don't have a readlink() function, + such as DJGPP 2.03 and mingw32. */ + +ssize_t +readlink (const char *name, char *buf _GL_UNUSED, + size_t bufsize _GL_UNUSED) +{ + struct stat statbuf; + + /* In general we should use lstat() here, not stat(). But on platforms + without symbolic links, lstat() - if it exists - would be equivalent to + stat(), therefore we can use stat(). This saves us a configure check. */ + if (stat (name, &statbuf) >= 0) + errno = EINVAL; + return -1; +} + +#else /* HAVE_READLINK */ + +# undef readlink + +/* readlink() wrapper that uses correct types, for systems like cygwin + 1.5.x where readlink returns int, and which rejects trailing slash, + for Solaris 9. */ + +ssize_t +rpl_readlink (const char *name, char *buf, size_t bufsize) +{ +# if READLINK_TRAILING_SLASH_BUG + size_t len = strlen (name); + if (len && name[len - 1] == '/') + { + /* Even if name without the slash is a symlink to a directory, + both lstat() and stat() must resolve the trailing slash to + the directory rather than the symlink. We can therefore + safely use stat() to distinguish between EINVAL and + ENOTDIR/ENOENT, avoiding extra overhead of rpl_lstat(). */ + struct stat st; + if (stat (name, &st) == 0) + errno = EINVAL; + return -1; + } +# endif /* READLINK_TRAILING_SLASH_BUG */ + return readlink (name, buf, bufsize); +} + +#endif /* HAVE_READLINK */ |