/* save-cwd.c -- Save and restore current working directory.
- Copyright (C) 1995, 1997, 1998, 2003, 2004 Free Software Foundation, Inc.
+
+ Copyright (C) 1995, 1997, 1998, 2003, 2004, 2005 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
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software Foundation,
- Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+ Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
/* Written by Jim Meyering. */
#include <errno.h>
#include "chdir-long.h"
+#include "unistd-safer.h"
#include "xgetcwd.h"
+/* On systems without the fchdir function (WOE), pretend that open
+ always returns -1 so that save_cwd resorts to using xgetcwd.
+ Since chdir_long requires fchdir, use chdir instead. */
+#if !HAVE_FCHDIR
+# undef open
+# define open(File, Flags) (-1)
+# undef fchdir
+# define fchdir(Fd) (abort (), -1)
+# undef chdir_long
+# define chdir_long(Dir) chdir (Dir)
+#endif
+
/* Record the location of the current working directory in CWD so that
the program may change to other directories and later use restore_cwd
to return to the recorded location. This function may allocate
closed; return non-zero -- in that case, free_cwd need not be
called, but doing so is ok. Otherwise, return zero.
- The `raison d'etre' for this interface is that some systems lack
- support for fchdir, and getcwd is not robust or as efficient.
+ The `raison d'etre' for this interface is that the working directory
+ is sometimes inaccessible, and getcwd is not robust or as efficient.
So, we prefer to use the open/fchdir approach, but fall back on
- getcwd if necessary. Some systems lack fchdir altogether: OS/2,
- Cygwin (as of March 2003), SCO Xenix. At least SunOS 4 and Irix 5.3
- provide the function, yet it doesn't work for partitions on which
- auditing is enabled. */
+ getcwd if necessary.
+
+ Some systems lack fchdir altogether: e.g., OS/2, pre-2001 Cygwin,
+ SCO Xenix. Also, SunOS 4 and Irix 5.3 provide the function, yet it
+ doesn't work for partitions on which auditing is enabled. If
+ you're still using an obsolete system with these problems, please
+ send email to the maintainer of this code. */
int
save_cwd (struct saved_cwd *cwd)
{
-#if !HAVE_FCHDIR
-# undef fchdir
-# define fchdir(x) (abort (), 0)
- bool have_working_fchdir = false;
- bool fchdir_needs_testing = false;
-#elif (__sgi || __sun)
- static bool have_working_fchdir = true;
- bool fchdir_needs_testing = true;
-#else
- bool have_working_fchdir = true;
- bool fchdir_needs_testing = false;
-#endif
-
- cwd->desc = -1;
cwd->name = NULL;
- if (have_working_fchdir)
+ cwd->desc = fd_safer (open (".", O_RDONLY));
+ if (cwd->desc < 0)
{
- cwd->desc = open (".", O_RDONLY);
+ cwd->desc = fd_safer (open (".", O_WRONLY));
if (cwd->desc < 0)
{
- cwd->desc = open (".", O_WRONLY);
- if (cwd->desc < 0)
- {
- cwd->name = xgetcwd ();
- return cwd->name ? 0 : -1;
- }
- }
-
- /* On SunOS 4 and IRIX 5.3, fchdir returns EINVAL when auditing
- is enabled, so we have to fall back to chdir. */
- if (fchdir_needs_testing && fchdir (cwd->desc) != 0)
- {
- int saved_errno = errno;
- close (cwd->desc);
- cwd->desc = -1;
- if (saved_errno != EINVAL)
- {
- errno = saved_errno;
- return -1;
- }
- have_working_fchdir = false;
+ cwd->name = xgetcwd ();
+ return cwd->name ? 0 : -1;
}
}
- if (!have_working_fchdir)
- {
- cwd->name = xgetcwd ();
- if (cwd->name == NULL)
- return -1;
- }
return 0;
}