*** empty log message ***

[gnulib.git] / lib / save-cwd.c

diff --git a/lib/save-cwd.c b/lib/save-cwd.c
index 564c918..068ff0a 100644 (file)
--- a/lib/save-cwd.c
+++ b/lib/save-cwd.c
@@ -1,5 +1,5 @@
 /* save-cwd.c -- Save and restore current working directory.
-   Copyright (C) 1995, 1997, 1998 Free Software Foundation, Inc.
+   Copyright (C) 1995, 1997, 1998, 2003 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
@@ -15,7 +15,7 @@
    along with this program; if not, write to the Free Software Foundation,
    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
 
-/* Written by Jim Meyering <meyering@na-net.ornl.gov>.  */
+/* Written by Jim Meyering.  */
 
 #if HAVE_CONFIG_H
 # include "config.h"
@@ -42,10 +42,12 @@
 extern int errno;
 #endif
 
-#include "save-cwd.h"
-#include "error.h"
+#ifndef O_DIRECTORY
+# define O_DIRECTORY 0
+#endif
 
-char *xgetcwd PARAMS ((void));
+#include "save-cwd.h"
+#include "xgetcwd.h"
 
 /* Record the location of the current working directory in CWD so that
    the program may change to other directories and later use restore_cwd
@@ -54,7 +56,15 @@ char *xgetcwd PARAMS ((void));
    use free_cwd to perform the necessary free or close.  Upon failure,
    no memory is allocated, any locally opened file descriptors are
    closed;  return non-zero -- in that case, free_cwd need not be
-   called, but doing so is ok.  Otherwise, return zero.  */
+   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.
+   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 SunOS4 and Irix 5.3
+   provide the function, yet it doesn't work for partitions on which
+   auditing is enabled.  */
 
 int
 save_cwd (struct saved_cwd *cwd)
@@ -67,16 +77,13 @@ save_cwd (struct saved_cwd *cwd)
   if (have_working_fchdir)
     {
 #if HAVE_FCHDIR
-      cwd->desc = open (".", O_RDONLY);
+      cwd->desc = open (".", O_RDONLY | O_DIRECTORY);
       if (cwd->desc < 0)
-       {
-         error (0, errno, "cannot open current directory");
-         return 1;
-       }
+       return 1;
 
 # if __sun__ || sun
-      /* On SunOS 4, fchdir returns EINVAL if accounting is enabled,
-        so we have to fall back to chdir.  */
+      /* On SunOS 4 and IRIX 5.3, fchdir returns EINVAL when auditing
+        is enabled, so we have to fall back to chdir.  */
       if (fchdir (cwd->desc))
        {
          if (errno == EINVAL)
@@ -87,9 +94,10 @@ save_cwd (struct saved_cwd *cwd)
            }
          else
            {
-             error (0, errno, "current directory");
+             int saved_errno = errno;
              close (cwd->desc);
              cwd->desc = -1;
+             errno = saved_errno;
              return 1;
            }
        }
@@ -104,39 +112,22 @@ save_cwd (struct saved_cwd *cwd)
     {
       cwd->name = xgetcwd ();
       if (cwd->name == NULL)
-       {
-         error (0, errno, "cannot get current directory");
-         return 1;
-       }
+       return 1;
     }
   return 0;
 }
 
 /* Change to recorded location, CWD, in directory hierarchy.
-   If "saved working directory", NULL))
-   */
+   Upon failure, return nonzero (errno is set by chdir or fchdir).
+   Upon success, return zero.  */
 
 int
-restore_cwd (const struct saved_cwd *cwd, const char *dest, const char *from)
+restore_cwd (const struct saved_cwd *cwd)
 {
-  int fail = 0;
-  if (cwd->desc >= 0)
-    {
-      if (fchdir (cwd->desc))
-       {
-         error (0, errno, "cannot return to %s%s%s",
-                (dest ? dest : "saved working directory"),
-                (from ? " from " : ""),
-                (from ? from : ""));
-         fail = 1;
-       }
-    }
-  else if (chdir (cwd->name) < 0)
-    {
-      error (0, errno, "%s", cwd->name);
-      fail = 1;
-    }
-  return fail;
+  if (0 <= cwd->desc)
+    return fchdir (cwd->desc) < 0;
+  else
+    return chdir (cwd->name) < 0;
 }
 
 void