75 lines
2.3 KiB
C
75 lines
2.3 KiB
C
/* Stub for readlink().
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Copyright (C) 2003-2007, 2009-2020 Free Software Foundation, Inc.
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <https://www.gnu.org/licenses/>. */
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#include <config.h>
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/* Specification. */
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#include <unistd.h>
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#include <errno.h>
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#include <string.h>
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#include <sys/stat.h>
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#if !HAVE_READLINK
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/* readlink() substitute for systems that don't have a readlink() function,
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such as DJGPP 2.03 and mingw32. */
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ssize_t
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readlink (const char *name, char *buf _GL_UNUSED,
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size_t bufsize _GL_UNUSED)
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{
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struct stat statbuf;
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/* In general we should use lstat() here, not stat(). But on platforms
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without symbolic links, lstat() - if it exists - would be equivalent to
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stat(), therefore we can use stat(). This saves us a configure check. */
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if (stat (name, &statbuf) >= 0)
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errno = EINVAL;
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return -1;
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}
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#else /* HAVE_READLINK */
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# undef readlink
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/* readlink() wrapper that uses correct types, for systems like cygwin
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1.5.x where readlink returns int, and which rejects trailing slash,
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for Solaris 9. */
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ssize_t
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rpl_readlink (const char *name, char *buf, size_t bufsize)
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{
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# if READLINK_TRAILING_SLASH_BUG
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size_t len = strlen (name);
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if (len && name[len - 1] == '/')
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{
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/* Even if name without the slash is a symlink to a directory,
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both lstat() and stat() must resolve the trailing slash to
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the directory rather than the symlink. We can therefore
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safely use stat() to distinguish between EINVAL and
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ENOTDIR/ENOENT, avoiding extra overhead of rpl_lstat(). */
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struct stat st;
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if (stat (name, &st) == 0)
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errno = EINVAL;
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return -1;
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}
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# endif /* READLINK_TRAILING_SLASH_BUG */
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return readlink (name, buf, bufsize);
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}
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#endif /* HAVE_READLINK */
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