X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fdirname.c;h=16552c64d2a377f7697bf604f2f32a59abc961e9;hb=a98bbee4c1388c33841d11b4bdc5d0a600a9deda;hp=237dd4b75b90ddb0106301a0e790125a49de11e2;hpb=ec4c2552456754b07b5d1d19b1c80c84d9cfa9c3;p=gnulib.git

diff --git a/lib/dirname.c b/lib/dirname.c
index 237dd4b75..16552c64d 100644
--- a/lib/dirname.c
+++ b/lib/dirname.c
@@ -1,5 +1,7 @@
-/* dirname.c -- return all but the last element in a path
-   Copyright (C) 1990, 1998 Free Software Foundation, Inc.
+/* dirname.c -- return all but the last element in a file name
+
+   Copyright (C) 1990, 1998, 2000, 2001, 2003, 2004, 2005, 2006 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
@@ -13,74 +15,71 @@
 
    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.  */
-
-#ifdef HAVE_CONFIG_H
-# include <config.h>
-#endif
-
-#ifdef STDC_HEADERS
-# include <stdlib.h>
-#else
-char *malloc ();
-#endif
-#if defined STDC_HEADERS || defined HAVE_STRING_H
-# include <string.h>
-#else
-# include <strings.h>
-# ifndef strrchr
-#  define strrchr rindex
-# endif
-#endif
-
-#include <ctype.h>
-
-#if defined STDC_HEADERS || (!defined isascii && !defined HAVE_ISASCII)
-# define IN_CTYPE_DOMAIN(c) 1
-#else
-# define IN_CTYPE_DOMAIN(c) isascii(c)
-#endif
-#define ISALPHA(Ch) (IN_CTYPE_DOMAIN (Ch) && isalpha (Ch))
-
-/* Return the leading directories part of PATH,
-   allocated with malloc.  If out of memory, return 0.
-   Assumes that trailing slashes have already been
-   removed.  */
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <config.h>
+
+#include "dirname.h"
+
+#include <string.h>
+#include "xalloc.h"
+
+/* Return the length of the prefix of FILE that will be used by
+   dir_name.  If FILE is in the working directory, this returns zero
+   even though `dir_name (FILE)' will return ".".  Works properly even
+   if there are trailing slashes (by effectively ignoring them).  */
+
+size_t
+dir_len (char const *file)
+{
+  size_t prefix_length = FILE_SYSTEM_PREFIX_LEN (file);
+  size_t length;
+
+  /* Advance prefix_length beyond important leading slashes.  */
+  prefix_length += (prefix_length != 0
+		    ? (FILE_SYSTEM_DRIVE_PREFIX_CAN_BE_RELATIVE
+		       && ISSLASH (file[prefix_length]))
+		    : (ISSLASH (file[0])
+		       ? ((DOUBLE_SLASH_IS_DISTINCT_ROOT
+			   && ISSLASH (file[1]) && ! ISSLASH (file[2])
+			   ? 2 : 1))
+		       : 0));
+
+  /* Strip the basename and any redundant slashes before it.  */
+  for (length = last_component (file) - file;
+       prefix_length < length; length--)
+    if (! ISSLASH (file[length - 1]))
+      break;
+  return length;
+}
+
+
+/* In general, we can't use the builtin `dirname' function if available,
+   since it has different meanings in different environments.
+   In some environments the builtin `dirname' modifies its argument.
+
+   Return the leading directories part of FILE, allocated with xmalloc.
+   Works properly even if there are trailing slashes (by effectively
+   ignoring them).  Unlike POSIX dirname(), FILE cannot be NULL.
+
+   If lstat (FILE) would succeed, then { chdir (dir_name (FILE));
+   lstat (base_name (FILE)); } will access the same file.  Likewise,
+   if the sequence { chdir (dir_name (FILE));
+   rename (base_name (FILE), "foo"); } succeeds, you have renamed FILE
+   to "foo" in the same directory FILE was in.  */
 
 char *
-dirname (path)
-     char *path;
+dir_name (char const *file)
 {
-  char *newpath;
-  char *slash;
-  int length;			/* Length of result, not including NUL.  */
-
-  slash = strrchr (path, '/');
-  if (slash == 0)
-    {
-      /* File is in the current directory.  */
-      path = ".";
-      length = 1;
-    }
-  else
-    {
-      char *lim = path;
-
-#ifdef MSDOS
-      /* If canonicalized "d:/path", leave alone the root case "d:/".  */
-      lim = (ISALPHA (path[0]) && path[1] == ':') ? path + 2 : path;
-#endif
-
-      /* Remove any trailing slashes from the result.  */
-      while (slash > path && *slash == '/')
-	--slash;
-
-      length = slash - path + 1;
-    }
-  newpath = (char *) malloc (length + 1);
-  if (newpath == 0)
-    return 0;
-  strncpy (newpath, path, length);
-  newpath[length] = 0;
-  return newpath;
+  size_t length = dir_len (file);
+  bool append_dot = (length == 0
+		     || (FILE_SYSTEM_DRIVE_PREFIX_CAN_BE_RELATIVE
+			 && length == FILE_SYSTEM_PREFIX_LEN (file)
+			 && file[2] != '\0' && ! ISSLASH (file[2])));
+  char *dir = xmalloc (length + append_dot + 1);
+  memcpy (dir, file, length);
+  if (append_dot)
+    dir[length++] = '.';
+  dir[length] = '\0';
+  return dir;
 }