On the Windows platform, Microsoft documents the rename function
as refusing to replace existing destination files. This is
allowed by C89 (and C99) but it is not POSIX-compliant, and it
can be quite surprising to programs that want to atomically
replace files.
Here is a gnulib commit that I am proposing. It (cross)compiles
on Mingw, but I am waiting to hear back from my Windows tester to
find out whether it actually solves the problem for him.
Comments?
commit 7243a5ecda0db712da438b1cfcad89c18264fdb3
Author: Ben Pfaff <b...@cs.stanford.edu>
Date: Fri Mar 20 22:02:50 2009 -0700
Make rename replace existing destinations on Windows.
diff --git a/ChangeLog b/ChangeLog
index 4a23101..642a615 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2009-03-20 Ben Pfaff <b...@gnu.org>
+
+ Make rename replace existing destinations on Windows.
+ * m4/rename.m4: Add test for Mingw.
+ * lib/rename.c: Add rename replacement that uses MoveFileEx with
+ MOVEFILE_REPLACE_EXISTING to replace existing destination files.
+ * doc/posix-functions/rename.texi: Document.
+
2009-03-20 Bruno Haible <br...@clisp.org>
Make sockets.h self-contained.
diff --git a/doc/posix-functions/rename.texi b/doc/posix-functions/rename.texi
index 62b1fc8..aa7287a 100644
--- a/doc/posix-functions/rename.texi
+++ b/doc/posix-functions/rename.texi
@@ -12,8 +12,15 @@ Portability problems fixed by Gnulib:
This function does not work when the source file name ends in a slash on
some platforms:
SunOS 4.1.
+...@item
+This function will not replace an existing destination on some
+platforms:
+mingw.
@end itemize
Portability problems not fixed by Gnulib:
@itemize
+This function will not replace a destination that is currently opened
+by any process:
+mingw.
@end itemize
diff --git a/lib/rename.c b/lib/rename.c
index 9667c39..f0486d9 100644
--- a/lib/rename.c
+++ b/lib/rename.c
@@ -1,8 +1,9 @@
-/* Work around the bug in some systems whereby rename fails when the source
- file has a trailing slash. The rename functions of SunOS 4.1.1_U1 and
- mips-dec-ultrix4.4 have this bug.
+/* Work around rename bugs in some systems. On SunOS 4.1.1_U1
+ and mips-dec-ultrix4.4, rename fails when the source file has
+ a trailing slash. On mingw, rename fails when the destination
+ exists.
- Copyright (C) 2001, 2002, 2003, 2005, 2006 Free Software Foundation, Inc.
+ Copyright (C) 2001, 2002, 2003, 2005, 2006, 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
@@ -22,6 +23,99 @@
#include <config.h>
#undef rename
+#if RENAME_DEST_EXISTS_BUG
+/* This replacement must come first, otherwise when cross
+ * compiling to Windows we will guess that it has the trailing
+ * slash bug and entirely miss this one. */
+#include <errno.h>
+
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+
+/* Rename the file SRC to DST. This replacement is necessary on
+ Windows, on which the system rename function will not replace
+ an existing DST. */
+int
+rpl_rename (char const *src, char const *dst)
+{
+ if (MoveFileEx (src, dst, MOVEFILE_REPLACE_EXISTING))
+ return 0;
+ else
+ {
+ switch (GetLastError())
+ {
+ case ERROR_FILE_NOT_FOUND:
+ case ERROR_PATH_NOT_FOUND:
+ case ERROR_BAD_PATHNAME:
+ case ERROR_DIRECTORY:
+ errno = ENOENT;
+ break;
+
+ case ERROR_ACCESS_DENIED:
+ case ERROR_SHARING_VIOLATION:
+ errno = EACCES;
+ break;
+
+ case ERROR_OUTOFMEMORY:
+ errno = ENOMEM;
+ break;
+
+ case ERROR_CURRENT_DIRECTORY:
+ errno = EBUSY;
+ break;
+
+ case ERROR_NOT_SAME_DEVICE:
+ errno = EXDEV;
+ break;
+
+ case ERROR_WRITE_PROTECT:
+ errno = EROFS;
+ break;
+
+ case ERROR_WRITE_FAULT:
+ case ERROR_READ_FAULT:
+ case ERROR_GEN_FAILURE:
+ errno = EIO;
+ break;
+
+ case ERROR_HANDLE_DISK_FULL:
+ case ERROR_DISK_FULL:
+ case ERROR_DISK_TOO_FRAGMENTED:
+ errno = ENOSPC;
+ break;
+
+ case ERROR_FILE_EXISTS:
+ case ERROR_ALREADY_EXISTS:
+ errno = EEXIST;
+ break;
+
+ case ERROR_BUFFER_OVERFLOW:
+ case ERROR_FILENAME_EXCED_RANGE:
+ errno = ENAMETOOLONG;
+ break;
+
+ case ERROR_INVALID_NAME:
+ case ERROR_DELETE_PENDING:
+ errno = EPERM; /* ? */
+ break;
+
+#ifndef ERROR_FILE_TOO_LARGE
+/* This value is documented but not defined in all versions of windows.h. */
+#define ERROR_FILE_TOO_LARGE 223
+#endif
+ case ERROR_FILE_TOO_LARGE:
+ errno = EFBIG;
+ break;
+
+ default:
+ errno = EINVAL;
+ break;
+ }
+
+ return -1;
+ }
+}
+#elif RENAME_TRAILING_SLASH_BUG
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
@@ -54,3 +148,4 @@ rpl_rename (char const *src, char const *dst)
return ret_val;
}
+#endif /* RENAME_TRAILING_SLASH_BUG */
diff --git a/m4/rename.m4 b/m4/rename.m4
index fa7ae8d..9829308 100644
--- a/m4/rename.m4
+++ b/m4/rename.m4
@@ -15,7 +15,8 @@ dnl
AC_DEFUN([gl_FUNC_RENAME],
[
- AC_CACHE_CHECK([whether rename is broken],
+ AC_REQUIRE([AC_CANONICAL_HOST])
+ AC_CACHE_CHECK([whether rename is broken with a trailing slash],
gl_cv_func_rename_trailing_slash_bug,
[
rm -rf conftest.d1 conftest.d2
@@ -37,13 +38,29 @@ AC_DEFUN([gl_FUNC_RENAME],
rm -rf conftest.d1 conftest.d2
])
- if test $gl_cv_func_rename_trailing_slash_bug = yes; then
+ AC_CACHE_CHECK([whether rename is broken when the destination exists],
+ gl_cv_func_rename_dest_exists_bug,
+ [
+ case "$host_os" in
+ mingw*) gl_cv_func_rename_dest_exists_bug=yes ;;
+ *) gl_cv_func_rename_dest_exists_bug=no ;;
+ esac
+ ])
+ if test $gl_cv_func_rename_trailing_slash_bug = yes ||
+ test $gl_cv_func_rename_dest_exists_bug = yes; then
AC_LIBOBJ([rename])
AC_DEFINE([rename], [rpl_rename],
[Define to rpl_rename if the replacement function should be used.])
- AC_DEFINE([RENAME_TRAILING_SLASH_BUG], [1],
- [Define if rename does not work for source file names with a trailing
- slash, like the one from SunOS 4.1.1_U1.])
+ if test $gl_cv_func_rename_trailing_slash_bug; then
+ AC_DEFINE([RENAME_TRAILING_SLASH_BUG], [1],
+ [Define if rename does not work for source file names with a trailing
+ slash, like the one from SunOS 4.1.1_U1.])
+ fi
+ if test $gl_cv_func_rename_dest_exists_bug; then
+ AC_DEFINE([RENAME_DEST_EXISTS_BUG], [1],
+ [Define if rename does not work when the destination file exists,
+ as on Windows.])
+ fi
gl_PREREQ_RENAME
fi
])
--
"If a person keeps faithfully busy each hour of the working day, he
can count on waking up some morning to find himself one of the
competent ones of his generation."
--William James
