2009-09-09 Eric Blake <ebb9@byu.net>
+ link: fix platform bugs
+ * m4/link.m4 (gl_FUNC_LINK): Detect Solaris and Cygwin bugs.
+ * lib/link.c (link): Work around them. Fix related mingw bug.
+ * m4/unistd_h.m4 (gl_UNISTD_H_DEFAULTS): Add REPLACE_LINK.
+ * modules/unistd (Makefile.am): Substitute it.
+ * lib/unistd.in.h (link): Declare replacement.
+ * doc/posix-functions/link.texi (link): Document this.
+ * modules/link (Depends-on): Add strdup-posix, sys_stat.
+
test-link: consolidate into single C program, test more cases
* tests/test-link.sh: Delete.
* tests/test-link.c: Test more error conditions. Exposes bugs on
#include <config.h>
-#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
-
-#define WIN32_LEAN_AND_MEAN
#include <unistd.h>
-#include <windows.h>
#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+
+#if !HAVE_LINK
+# if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+
+# define WIN32_LEAN_AND_MEAN
+# include <windows.h>
/* CreateHardLink was introduced only in Windows 2000. */
typedef BOOL (WINAPI * CreateHardLinkFuncType) (LPCTSTR lpFileName,
}
int
-link (const char *path1, const char *path2)
+link (const char *file1, const char *file2)
{
+ char *dir;
+ size_t len1 = strlen (file1);
+ size_t len2 = strlen (file2);
if (!initialized)
initialize ();
if (CreateHardLinkFunc == NULL)
errno = EPERM;
return -1;
}
- if (CreateHardLinkFunc (path2, path1, NULL) == 0)
+ /* Reject trailing slashes on non-directories; mingw does not
+ support hard-linking directories. */
+ if ((len1 && (file1[len1 - 1] == '/' || file1[len1 - 1] == '\\'))
+ || (len2 && (file2[len2 - 1] == '/' || file2[len2 - 1] == '\\')))
+ {
+ struct stat st;
+ if (stat (file1, &st) == 0 && S_ISDIR (st.st_mode))
+ errno = EPERM;
+ else
+ errno = ENOTDIR;
+ return -1;
+ }
+ /* CreateHardLink("b/.","a",NULL) creates file "b", so we must check
+ that dirname(file2) exists. */
+ dir = strdup (file2);
+ if (!dir)
+ return -1;
+ {
+ struct stat st;
+ char *p = strchr (dir, '\0');
+ while (dir < p && (*--p != '/' && *p != '\\'));
+ *p = '\0';
+ if (p != dir && stat (dir, &st) == -1)
+ {
+ int saved_errno = errno;
+ free (dir);
+ errno = saved_errno;
+ return -1;
+ }
+ free (dir);
+ }
+ /* Now create the link. */
+ if (CreateHardLinkFunc (file2, file1, NULL) == 0)
{
/* It is not documented which errors CreateHardLink() can produce.
* The following conversions are based on tests on a Windows XP SP2
return 0;
}
-#else /* !Windows */
+# else /* !Windows */
+
+# error "This platform lacks a link function, and Gnulib doesn't provide a replacement. This is a bug in Gnulib."
+
+# endif /* !Windows */
+#else /* HAVE_LINK */
-#error "This platform lacks a link function, and Gnulib doesn't provide a replacement. This is a bug in Gnulib."
+# undef link
-#endif /* !Windows */
+/* Create a hard link from FILE1 to FILE2, working around platform bugs. */
+int
+rpl_link (char const *file1, char const *file2)
+{
+ /* Reject trailing slashes on non-directories. */
+ size_t len1 = strlen (file1);
+ size_t len2 = strlen (file2);
+ if ((len1 && file1[len1 - 1] == '/')
+ || (len2 && file2[len2 - 1] == '/'))
+ {
+ /* Let link() decide whether hard-linking directories is legal.
+ If stat() fails, link() will probably fail for the same
+ reason; so we only have to worry about successful stat() and
+ non-directory. */
+ struct stat st;
+ if (stat (file1, &st) == 0 && !S_ISDIR (st.st_mode))
+ {
+ errno = ENOTDIR;
+ return -1;
+ }
+ }
+ else
+ {
+ /* Fix Cygwin 1.5.x bug where link("a","b/.") creates file "b". */
+ char *dir = strdup (file2);
+ struct stat st;
+ char *p;
+ if (!dir)
+ return -1;
+ /* We already know file2 does not end in slash. Strip off the
+ basename, then check that the dirname exists. */
+ p = strrchr (dir, '/');
+ if (p)
+ {
+ *p = '\0';
+ if (stat (dir, &st) == -1)
+ {
+ int saved_errno = errno;
+ free (dir);
+ errno = saved_errno;
+ return -1;
+ }
+ }
+ free (dir);
+ }
+ return link (file1, file2);
+}
+#endif /* HAVE_LINK */
-# link.m4 serial 1
+# link.m4 serial 2
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,
if test $ac_cv_func_link = no; then
HAVE_LINK=0
AC_LIBOBJ([link])
- gl_PREREQ_LINK
+ else
+ AC_CACHE_CHECK([whether link handles trailing slash correctly],
+ [gl_cv_func_link_works],
+ [touch conftest.a
+ AC_RUN_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <unistd.h>
+]], [[return !link ("conftest.a", "conftest.b/");]])],
+ [gl_cv_func_link_works=yes], [gl_cv_func_link_works=no],
+ [gl_cv_func_link_works="guessing no"])
+ rm -f conftest.a conftest.b])
+ if test $gl_cv_func_link_works != yes; then
+ REPLACE_LINK=1
+ AC_LIBOBJ([link])
+ fi
fi
])
-
-# Prerequisites of lib/link.c.
-AC_DEFUN([gl_PREREQ_LINK], [:])
-# unistd_h.m4 serial 24
+# unistd_h.m4 serial 25
dnl Copyright (C) 2006-2009 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
REPLACE_GETCWD=0; AC_SUBST([REPLACE_GETCWD])
REPLACE_GETPAGESIZE=0; AC_SUBST([REPLACE_GETPAGESIZE])
REPLACE_LCHOWN=0; AC_SUBST([REPLACE_LCHOWN])
+ REPLACE_LINK=0; AC_SUBST([REPLACE_LINK])
REPLACE_LSEEK=0; AC_SUBST([REPLACE_LSEEK])
REPLACE_WRITE=0; AC_SUBST([REPLACE_WRITE])
UNISTD_H_HAVE_WINSOCK2_H=0; AC_SUBST([UNISTD_H_HAVE_WINSOCK2_H])
projects / gnulib.git / commitdiff