symlink("a","link/") mistakenly succeeds.
* modules/symlink: New file.
* m4/symlink.m4 (gl_FUNC_SYMLINK): Likewise.
* lib/symlink.c: Likewise.
* m4/unistd_h.m4 (gl_UNISTD_H_DEFAULTS): Add defaults.
* modules/unistd (Makefile.am): Substitute them.
* lib/unistd.in.h (symlink): Declare replacement.
* MODULES.html.sh (File system functions): Mention it.
* doc/posix-functions/symlink.texi (symlink): Likewise.
* modules/symlink-tests: New test.
* tests/test-symlink.c: Likewise.
Signed-off-by: Eric Blake <ebb9@byu.net>
+2009-09-23 Eric Blake <ebb9@byu.net>
+
+ symlink: new module, for Solaris 9 bug
+ * modules/symlink: New file.
+ * m4/symlink.m4 (gl_FUNC_SYMLINK): Likewise.
+ * lib/symlink.c: Likewise.
+ * m4/unistd_h.m4 (gl_UNISTD_H_DEFAULTS): Add defaults.
+ * modules/unistd (Makefile.am): Substitute them.
+ * lib/unistd.in.h (symlink): Declare replacement.
+ * MODULES.html.sh (File system functions): Mention it.
+ * doc/posix-functions/symlink.texi (symlink): Likewise.
+ * modules/symlink-tests: New test.
+ * tests/test-symlink.c: Likewise.
+
2009-09-23 Bruno Haible <bruno@clisp.org>
* gnulib-tool (func_import): Add 'link-warning' to testsrelated_modules
func_module savewd
func_module stat-macros
func_module stat-time
+ func_module symlink
func_module symlinkat
func_module tmpdir
func_module unlinkdir
POSIX specification: @url{http://www.opengroup.org/onlinepubs/9699919799/functions/symlink.html}
-Gnulib module: ---
+Gnulib module: symlink
Portability problems fixed by Gnulib:
@itemize
+@item
+On some systems, @code{symlink(value,"name/")} mistakenly creates a
+symlink:
+Solaris 9
+@item
+This function is missing on some platforms; however, the replacement
+always fails with @code{EPERM}:
+mingw.
@end itemize
Portability problems not fixed by Gnulib:
@itemize
@item
-This function is missing on some platforms:
-mingw.
+Some file systems do not support symbolic links.
@end itemize
--- /dev/null
+/* Stub for symlink().
+ 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/>. */
+
+#include <config.h>
+
+/* Specification. */
+#include <unistd.h>
+
+#include <errno.h>
+#include <string.h>
+#include <sys/stat.h>
+
+
+#if HAVE_SYMLINK
+
+# undef symlink
+
+/* Create a symlink, but reject trailing slash. */
+int
+rpl_symlink (char const *contents, char const *name)
+{
+ size_t len = strlen (name);
+ if (len && name[len - 1] == '/')
+ {
+ struct stat st;
+ if (lstat (name, &st) == 0)
+ errno = EEXIST;
+ return -1;
+ }
+ return symlink (contents, name);
+}
+
+#else /* !HAVE_SYMLINK */
+
+/* The system does not support symlinks. */
+int
+symlink (char const *contents _UNUSED_PARAMETER_,
+ char const *name _UNUSED_PARAMETER_)
+{
+ errno = ENOSYS;
+ return -1;
+}
+
+#endif /* !HAVE_SYMLINK */
#endif
+#if @GNULIB_SYMLINK@
+# if @REPLACE_SYMLINK@
+# undef symlink
+# define symlink rpl_symlink
+# endif
+# if !@HAVE_SYMLINK@ || @REPLACE_SYMLINK@
+int symlink (char const *contents, char const *file);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef symlink
+# define symlink(c,n) \
+ (GL_LINK_WARNING ("symlink is not portable - " \
+ "use gnulib module symlink for portability"), \
+ symlink (c, n))
+#endif
+
+
#if @GNULIB_SYMLINKAT@
# if !@HAVE_SYMLINKAT@
int symlinkat (char const *contents, int fd, char const *file);
--- /dev/null
+# serial 1
+# See if we need to provide symlink replacement.
+
+dnl Copyright (C) 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,
+dnl with or without modifications, as long as this notice is preserved.
+
+# Written by Eric Blake.
+
+AC_DEFUN([gl_FUNC_SYMLINK],
+[
+ AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+ AC_CHECK_FUNCS_ONCE([symlink])
+ dnl The best we can do on mingw is provide a dummy that always fails, so
+ dnl that compilation can proceed with fewer ifdefs. On Solaris 9, we
+ dnl want to fix a bug with trailing slash handling.
+ if test $ac_cv_func_symlink = no; then
+ HAVE_SYMLINK=0
+ AC_LIBOBJ([symlink])
+ else
+ AC_CACHE_CHECK([whether symlink handles trailing slash correctly],
+ [gl_cv_func_symlink_works],
+ [AC_RUN_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <unistd.h>
+]], [[return !symlink ("a", "conftest.link/");]])],
+ [gl_cv_func_symlink_works=yes], [gl_cv_func_symlink_works=no],
+ [gl_cv_func_symlink_works="guessing no"])])
+ if test "$gl_cv_func_symlink_works" != yes; then
+ REPLACE_SYMLINK=1
+ AC_LIBOBJ([symlink])
+ fi
+ fi
+])
GNULIB_READLINKAT=0; AC_SUBST([GNULIB_READLINKAT])
GNULIB_RMDIR=0; AC_SUBST([GNULIB_RMDIR])
GNULIB_SLEEP=0; AC_SUBST([GNULIB_SLEEP])
+ GNULIB_SYMLINK=0; AC_SUBST([GNULIB_SYMLINK])
GNULIB_SYMLINKAT=0; AC_SUBST([GNULIB_SYMLINKAT])
GNULIB_UNISTD_H_GETOPT=0; AC_SUBST([GNULIB_UNISTD_H_GETOPT])
GNULIB_UNISTD_H_SIGPIPE=0; AC_SUBST([GNULIB_UNISTD_H_SIGPIPE])
HAVE_READLINK=1; AC_SUBST([HAVE_READLINK])
HAVE_READLINKAT=1; AC_SUBST([HAVE_READLINKAT])
HAVE_SLEEP=1; AC_SUBST([HAVE_SLEEP])
+ HAVE_SYMLINK=1; AC_SUBST([HAVE_SYMLINK])
HAVE_SYMLINKAT=1; AC_SUBST([HAVE_SYMLINKAT])
HAVE_DECL_ENVIRON=1; AC_SUBST([HAVE_DECL_ENVIRON])
HAVE_DECL_GETLOGIN_R=1; AC_SUBST([HAVE_DECL_GETLOGIN_R])
REPLACE_LINK=0; AC_SUBST([REPLACE_LINK])
REPLACE_LSEEK=0; AC_SUBST([REPLACE_LSEEK])
REPLACE_RMDIR=0; AC_SUBST([REPLACE_RMDIR])
+ REPLACE_SYMLINK=0; AC_SUBST([REPLACE_SYMLINK])
REPLACE_UNLINK=0; AC_SUBST([REPLACE_UNLINK])
REPLACE_UNLINKAT=0; AC_SUBST([REPLACE_UNLINKAT])
REPLACE_WRITE=0; AC_SUBST([REPLACE_WRITE])
--- /dev/null
+Description:
+symlink(): create a symlink, if possible
+
+Files:
+lib/symlink.c
+m4/symlink.m4
+
+Depends-on:
+lstat
+unistd
+
+configure.ac:
+gl_FUNC_SYMLINK
+gl_UNISTD_MODULE_INDICATOR([symlink])
+
+Makefile.am:
+
+Include:
+<unistd.h>
+
+License:
+LGPL
+
+Maintainer:
+Eric Blake
--- /dev/null
+Files:
+tests/test-symlink.c
+
+Depends-on:
+
+configure.ac:
+
+Makefile.am:
+TESTS += test-symlink
+check_PROGRAMS += test-symlink
-e 's|@''GNULIB_READLINKAT''@|$(GNULIB_READLINKAT)|g' \
-e 's|@''GNULIB_RMDIR''@|$(GNULIB_RMDIR)|g' \
-e 's|@''GNULIB_SLEEP''@|$(GNULIB_SLEEP)|g' \
+ -e 's|@''GNULIB_SYMLINK''@|$(GNULIB_SYMLINK)|g' \
-e 's|@''GNULIB_SYMLINKAT''@|$(GNULIB_SYMLINKAT)|g' \
-e 's|@''GNULIB_UNISTD_H_GETOPT''@|$(GNULIB_UNISTD_H_GETOPT)|g' \
-e 's|@''GNULIB_UNISTD_H_SIGPIPE''@|$(GNULIB_UNISTD_H_SIGPIPE)|g' \
-e 's|@''HAVE_READLINK''@|$(HAVE_READLINK)|g' \
-e 's|@''HAVE_READLINKAT''@|$(HAVE_READLINKAT)|g' \
-e 's|@''HAVE_SLEEP''@|$(HAVE_SLEEP)|g' \
+ -e 's|@''HAVE_SYMLINK''@|$(HAVE_SYMLINK)|g' \
-e 's|@''HAVE_SYMLINKAT''@|$(HAVE_SYMLINKAT)|g' \
-e 's|@''HAVE_UNLINKAT''@|$(HAVE_UNLINKAT)|g' \
-e 's|@''HAVE_DECL_ENVIRON''@|$(HAVE_DECL_ENVIRON)|g' \
-e 's|@''REPLACE_LINK''@|$(REPLACE_LINK)|g' \
-e 's|@''REPLACE_LSEEK''@|$(REPLACE_LSEEK)|g' \
-e 's|@''REPLACE_RMDIR''@|$(REPLACE_RMDIR)|g' \
+ -e 's|@''REPLACE_SYMLINK''@|$(REPLACE_SYMLINK)|g' \
-e 's|@''REPLACE_UNLINK''@|$(REPLACE_UNLINK)|g' \
-e 's|@''REPLACE_UNLINKAT''@|$(REPLACE_UNLINKAT)|g' \
-e 's|@''REPLACE_WRITE''@|$(REPLACE_WRITE)|g' \
--- /dev/null
+/* Tests of symlink.
+ 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 <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-symlink.t"
+
+int
+main ()
+{
+ /* Remove any leftovers from a previous partial run. */
+ ASSERT (system ("rm -rf " BASE "*") == 0);
+
+ if (symlink ("nowhere", BASE "link1"))
+ {
+ fputs ("skipping test: symlinks not supported on this filesystem\n",
+ stderr);
+ return 77;
+ }
+
+ /* Some systems allow the creation of 0-length symlinks as a synonym
+ for "."; but most reject it. */
+ errno = 0;
+ if (symlink ("", BASE "link2") == -1)
+ ASSERT (errno == ENOENT || errno == EINVAL);
+ else
+ ASSERT (unlink (BASE "link2") == 0);
+
+ /* Sanity checks of failures. */
+ errno = 0;
+ ASSERT (symlink ("nowhere", "") == -1);
+ ASSERT (errno == ENOENT);
+ errno = 0;
+ ASSERT (symlink ("nowhere", ".") == -1);
+ ASSERT (errno == EEXIST || errno == EINVAL);
+ errno = 0;
+ ASSERT (symlink ("somewhere", BASE "link1") == -1);
+ ASSERT (errno == EEXIST);
+ errno = 0;
+ ASSERT (symlink ("nowhere", BASE "link2/") == -1);
+ ASSERT (errno == ENOTDIR || errno == ENOENT);
+ ASSERT (mkdir (BASE "dir", 0700) == 0);
+ errno = 0;
+ ASSERT (symlink ("nowhere", BASE "dir") == -1);
+ ASSERT (errno == EEXIST);
+ errno = 0;
+ ASSERT (symlink ("nowhere", BASE "dir/") == -1);
+ ASSERT (errno == EEXIST);
+ ASSERT (close (creat (BASE "file", 0600)) == 0);
+ errno = 0;
+ ASSERT (symlink ("nowhere", BASE "file") == -1);
+ ASSERT (errno == EEXIST);
+ errno = 0;
+ ASSERT (symlink ("nowhere", BASE "file/") == -1);
+ ASSERT (errno == EEXIST || errno == ENOTDIR);
+
+ ASSERT (rmdir (BASE "dir") == 0);
+ ASSERT (unlink (BASE "file") == 0);
+ ASSERT (unlink (BASE "link1") == 0);
+
+ return 0;
+}
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