X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fdirname.c;h=c27e5b5d8b3bf42dc5dc050ee3f029f421949235;hb=80cb44fa0b094ad965f7bd88ad7e46e83df418d5;hp=d332b5e4695fe73f54226a748b3fad6729b02141;hpb=1c4c29a5cde23cbcd679c32056bbec9f34f746b1;p=gnulib.git

diff --git a/lib/dirname.c b/lib/dirname.c
index d332b5e46..c27e5b5d8 100644
--- a/lib/dirname.c
+++ b/lib/dirname.c
@@ -1,10 +1,12 @@
-/* dirname.c -- return all but the last element in a path
-   Copyright (C) 1990, 1998, 2000 Free Software Foundation, Inc.
+/* dirname.c -- return all but the last element in a file name
 
-   This program is free software; you can redistribute it and/or modify
+   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
-   the Free Software Foundation; either version 2, or (at your option)
-   any later version.
+   the Free Software Foundation; either version 3 of the License, 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
@@ -12,77 +14,71 @@
    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.  */
-
-#if 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 <assert.h>
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <config.h>
 
 #include "dirname.h"
 
-/* Return the leading directories part of PATH,
-   allocated with malloc.  If out of memory, return 0.
-   Assumes that trailing slashes have already been
-   removed.  */
+#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 *
-dir_name (const char *path)
+dir_name (char const *file)
 {
-  char *newpath;
-  char *slash;
-  int length;			/* Length of result, not including NUL.  */
-
-  slash = strrchr (path, '/');
-
-  /* Make sure there are no trailing slashes.  */
-  assert (slash == NULL	   /* There are no slashes in PATH.  */
-	  || slash[1] != 0 /* There is a non-NUL byte after the last slash.  */
-	  || path == slash /* PATH is just `/'.  */
-	  );
-
-  if (slash == 0)
-    {
-      /* File is in the current directory.  */
-      path = ".";
-      length = 1;
-    }
-  else
-    {
-      /* Remove any trailing slashes from the result.  */
-#ifdef __MSDOS__
-      const char *lim = ((path[0] >= 'A' && path[0] <= 'z' && path[1] == ':')
-			 ? path + 2 : path);
-
-      /* If canonicalized "d:/path", leave alone the root case "d:/".  */
-      while (slash > lim && *slash == '/')
-	--slash;
-#else
-      while (slash > path && *slash == '/')
-	--slash;
-#endif
-
-      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;
 }