# undef readlink
/* readlink() wrapper that uses correct types, for systems like cygwin
- 1.5.x where readlink returns int. */
+ 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);
}
-# readlink.m4 serial 6
+# readlink.m4 serial 7
dnl Copyright (C) 2003, 2007, 2009 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
/* Cause compilation failure if original declaration has wrong type. */
ssize_t readlink (const char *, char *, size_t);]])],
[gl_cv_decl_readlink_works=yes], [gl_cv_decl_readlink_works=no])])
- if test "$gl_cv_decl_readlink_works" != yes; then
+ AC_CACHE_CHECK([whether readlink handles trailing slash correctly],
+ [gl_cv_func_readlink_works],
+ [# We have readlink, so assume ln -s works.
+ ln -s conftest.no-such conftest.link
+ AC_RUN_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <unistd.h>
+]], [[char buf[20];
+ return readlink ("conftest.link/", buf, sizeof buf) != -1;]])],
+ [gl_cv_func_readlink_works=yes], [gl_cv_func_readlink_works=no],
+ [gl_cv_func_readlink_works="guessing no"])
+ rm -f conftest.link])
+ if test "$gl_cv_func_readlink_works" != yes; then
+ AC_DEFINE([READLINK_TRAILING_SLASH_BUG], [1], [Define to 1 if readlink
+ fails to recognize a trailing slash.])
+ REPLACE_READLINK=1
+ AC_LIBOBJ([readlink])
+ elif test "$gl_cv_decl_readlink_works" != yes; then
REPLACE_READLINK=1
AC_LIBOBJ([readlink])
fi
--- /dev/null
+/* Tests of readlink.
+ Copyright (C) 2009 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 <http://www.gnu.org/licenses/>. */
+
+/* Written by Eric Blake <ebb9@byu.net>, 2009. */
+
+#include <config.h>
+
+#include <unistd.h>
+
+#include <fcntl.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+
+#define ASSERT(expr) \
+ do \
+ { \
+ if (!(expr)) \
+ { \
+ fprintf (stderr, "%s:%d: assertion failed\n", __FILE__, __LINE__); \
+ fflush (stderr); \
+ abort (); \
+ } \
+ } \
+ while (0)
+
+#define BASE "test-readlink.t"
+
+int
+main ()
+{
+ char buf[80];
+
+ /* Remove any leftovers from a previous partial run. */
+ ASSERT (system ("rm -rf " BASE "*") == 0);
+
+ /* Sanity checks of failures. Mingw lacks symlink, but readlink can
+ still distinguish between various errors. */
+ memset (buf, 0xff, sizeof buf);
+ errno = 0;
+ ASSERT (readlink ("no_such", buf, sizeof buf) == -1);
+ ASSERT (errno == ENOENT);
+ errno = 0;
+ ASSERT (readlink ("no_such/", buf, sizeof buf) == -1);
+ ASSERT (errno == ENOENT);
+ errno = 0;
+ ASSERT (readlink ("", buf, sizeof buf) == -1);
+ ASSERT (errno == ENOENT);
+ errno = 0;
+ ASSERT (readlink (".", buf, sizeof buf) == -1);
+ ASSERT (errno == EINVAL);
+ errno = 0;
+ ASSERT (readlink ("./", buf, sizeof buf) == -1);
+ ASSERT (errno == EINVAL);
+ ASSERT (close (creat (BASE "file", 0600)) == 0);
+ errno = 0;
+ ASSERT (readlink (BASE "file", buf, sizeof buf) == -1);
+ ASSERT (errno == EINVAL);
+ errno = 0;
+ ASSERT (readlink (BASE "file/", buf, sizeof buf) == -1);
+ ASSERT (errno == ENOTDIR);
+ ASSERT (unlink (BASE "file") == 0);
+
+ /* Now test actual symlinks. */
+ if (symlink (BASE "dir", BASE "link"))
+ {
+ fputs ("skipping test: symlinks not supported on this filesystem\n",
+ stderr);
+ return 77;
+ }
+ ASSERT (mkdir (BASE "dir", 0700) == 0);
+ errno = 0;
+ ASSERT (readlink (BASE "link/", buf, sizeof buf) == -1);
+ ASSERT (errno == EINVAL);
+ {
+ /* Up till now, no readlink has been successful, so buf should be
+ unchanged. */
+ int i;
+ for (i = 0; i < sizeof buf; i++)
+ ASSERT (buf[i] == (char) 0xff);
+ }
+ {
+ size_t len = strlen (BASE "dir");
+ /* When passing too small of a buffer, expect the truncated
+ length. However, a size of 0 is not portable enough to
+ test. */
+ ASSERT (readlink (BASE "link", buf, 1) == 1);
+ ASSERT (buf[0] == BASE[0]);
+ ASSERT (buf[1] == (char) 0xff);
+ ASSERT (readlink (BASE "link", buf, len) == len);
+ ASSERT (strncmp (buf, BASE "dir", len) == 0);
+ ASSERT (buf[len] == (char) 0xff);
+ ASSERT (readlink (BASE "link", buf, sizeof buf) == len);
+ ASSERT (strncmp (buf, BASE "dir", len) == 0);
+ /* POSIX says rest of buf is unspecified; but in practice, it is
+ either left alone, or NUL-terminated. */
+ ASSERT (buf[len] == '\0' || buf[len] == (char) 0xff);
+ }
+ ASSERT (rmdir (BASE "dir") == 0);
+ ASSERT (unlink (BASE "link") == 0);
+
+ return 0;
+}
projects / gnulib.git / commitdiff