X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fsave-cwd.c;h=17d077db890d0b766d9d045f74c53d045c94b36d;hb=9b9bfb49af70f53f177c7a6563fa844a4a50c7db;hp=8413502eee81faeb87f328fd71625b4fcb85930a;hpb=0b403bac52c59ec0c93f6a215902187fc207683b;p=gnulib.git

diff --git a/lib/save-cwd.c b/lib/save-cwd.c
index 8413502ee..17d077db8 100644
--- 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 Free Software Foundation, Inc.
+   Copyright (C) 1995, 1997, 1998, 2003, 2004 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
@@ -12,40 +12,39 @@
    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., 675 Mass Ave, Cambridge, MA 02139, USA.  */
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
 
-/* Written Jim Meyering <meyering@na-net.ornl.gov>.  */
+/* Written by Jim Meyering.  */
 
-#ifdef HAVE_CONFIG_H
+#if HAVE_CONFIG_H
 # include "config.h"
 #endif
 
 #include <stdio.h>
+#include <stdlib.h>
 
-#ifdef STDC_HEADERS
-# include <stdlib.h>
-#endif
-
-#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
+#ifndef errno
 extern int errno;
 #endif
 
-#include "save-cwd.h"
-#include "error.h"
+#ifndef O_DIRECTORY
+# define O_DIRECTORY 0
+#endif
 
-char *xgetcwd __P((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
@@ -54,11 +53,18 @@ 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 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 SunOS 4 and Irix 5.3
+   provide the function, yet it doesn't work for partitions on which
+   auditing is enabled.  */
 
 int
-save_cwd (cwd)
-     struct saved_cwd *cwd;
+save_cwd (struct saved_cwd *cwd)
 {
   static int have_working_fchdir = 1;
 
@@ -67,17 +73,19 @@ save_cwd (cwd)
 
   if (have_working_fchdir)
     {
-#ifdef HAVE_FCHDIR
-      cwd->desc = open (".", O_RDONLY);
+#if HAVE_FCHDIR
+      cwd->desc = open (".", O_RDONLY | O_DIRECTORY);
+      if (cwd->desc < 0)
+	cwd->desc = open (".", O_WRONLY | O_DIRECTORY);
       if (cwd->desc < 0)
 	{
-	  error (0, errno, "cannot open current directory");
-	  return 1;
+	  cwd->name = xgetcwd ();
+	  return cwd->name == NULL;
 	}
 
 # 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)
@@ -88,15 +96,16 @@ save_cwd (cwd)
 	    }
 	  else
 	    {
-	      error (0, errno, "current directory");
+	      int saved_errno = errno;
 	      close (cwd->desc);
 	      cwd->desc = -1;
+	      errno = saved_errno;
 	      return 1;
 	    }
 	}
 # endif /* __sun__ || sun */
 #else
-#define fchdir(x) (abort (), 0)
+# define fchdir(x) (abort (), 0)
       have_working_fchdir = 0;
 #endif
     }
@@ -105,51 +114,29 @@ save_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 (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) < 0;
+  else
+    return chdir (cwd->name) < 0;
 }
 
 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);
 }
-