X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fsave-cwd.c;h=596b78c8d9a56d1d5710a27349988998851b93ab;hb=709c1f1fb17a388b106f6305a952da3ba802218e;hp=8e0d6dd51117a6ce50fccb8c05b38178229624da;hpb=ba1b7a20c80e727d795f98dac800dc8550dfb329;p=gnulib.git

diff --git a/lib/save-cwd.c b/lib/save-cwd.c
index 8e0d6dd51..596b78c8d 100644
--- a/lib/save-cwd.c
+++ b/lib/save-cwd.c
@@ -1,32 +1,48 @@
-#ifdef HAVE_CONFIG_H
+/* save-cwd.c -- Save and restore current working directory.
+
+   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
+   the Free Software Foundation; either version 2, 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, write to the Free Software Foundation,
+   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+/* Written by Jim Meyering.  */
+
+#if HAVE_CONFIG_H
 # include "config.h"
 #endif
 
-#include <stdio.h>
+#include "save-cwd.h"
 
-#ifdef STDC_HEADERS
-# include <stdlib.h>
-#endif
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
 
-#ifdef HAVE_UNISTD_H
+#if HAVE_UNISTD_H
 # include <unistd.h>
 #endif
 
-#ifdef HAVE_FCNTL_H
+#if HAVE_FCNTL_H
 # include <fcntl.h>
 #else
 # include <sys/file.h>
 #endif
 
 #include <errno.h>
-# ifndef errno
-extern int errno;
-#endif
-
-#include "save-cwd.h"
-#include "error.h"
 
-char *xgetcwd __P((void));
+#include "chdir-long.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
@@ -35,102 +51,56 @@ char *xgetcwd __P((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 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: 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 (cwd)
-     struct saved_cwd *cwd;
+save_cwd (struct saved_cwd *cwd)
 {
-  static int have_working_fchdir = 1;
-
-  cwd->desc = -1;
   cwd->name = NULL;
 
-  if (have_working_fchdir)
+  cwd->desc = open (".", O_RDONLY);
+  if (cwd->desc < 0)
     {
-#ifdef HAVE_FCHDIR
-      cwd->desc = open (".", O_RDONLY);
+      cwd->desc = open (".", O_WRONLY);
       if (cwd->desc < 0)
 	{
-	  error (0, errno, "cannot open current directory");
-	  return 1;
+	  cwd->name = xgetcwd ();
+	  return cwd->name ? 0 : -1;
 	}
-
-# if __sun__ || sun
-      /* On SunOS 4, fchdir returns EINVAL if accounting is enabled,
-	 so we have to fall back to chdir.  */
-      if (fchdir (cwd->desc))
-	{
-	  if (errno == EINVAL)
-	    {
-	      close (cwd->desc);
-	      cwd->desc = -1;
-	      have_working_fchdir = 0;
-	    }
-	  else
-	    {
-	      error (0, errno, "current directory");
-	      close (cwd->desc);
-	      cwd->desc = -1;
-	      return 1;
-	    }
-	}
-# endif /* __sun__ || sun */
-#else
-#define fchdir(x) (abort (), 0)
-      have_working_fchdir = 0;
-#endif
     }
 
-  if (!have_working_fchdir)
-    {
-      cwd->name = xgetcwd ();
-      if (cwd->name == NULL)
-	{
-	  error (0, errno, "cannot get current directory");
-	  return 1;
-	}
-    }
   return 0;
 }
 
 /* Change to recorded location, CWD, in directory hierarchy.
-   If "saved working directory", NULL))
-   */
+   Upon failure, return -1 (errno is set by chdir or fchdir).
+   Upon success, return zero.  */
 
 int
-restore_cwd (cwd, dest, from)
-     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);
+  else
+    return chdir_long (cwd->name);
 }
 
 void
-free_cwd (cwd)
-     struct saved_cwd *cwd;
+free_cwd (struct saved_cwd *cwd)
 {
   if (cwd->desc >= 0)
     close (cwd->desc);
   if (cwd->name)
     free (cwd->name);
 }
-