X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fbasename.c;h=fbe17ff910c8e8ee93eec92dbb7274739f8e821e;hb=2e7980e7a83a290bfaf0638bd95a9cbfeec0f67d;hp=56a6c04dd05f561b3275786397f686b35acc4891;hpb=3b8ba971c0e2dab242e8bbf8ede60a2fdee05f71;p=gnulib.git

diff --git a/lib/basename.c b/lib/basename.c
index 56a6c04dd..fbe17ff91 100644
--- a/lib/basename.c
+++ b/lib/basename.c
@@ -1,5 +1,7 @@
-/* basename.c -- return the last element in a path
-   Copyright (C) 1990 Free Software Foundation, Inc.
+/* basename.c -- return the last element in a file name
+
+   Copyright (C) 1990, 1998, 1999, 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
@@ -12,30 +14,116 @@
    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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
 
-#ifdef HAVE_CONFIG_H
 #include <config.h>
-#endif
 
-#if defined(STDC_HEADERS) || defined(HAVE_STRING_H)
+#include "dirname.h"
+
 #include <string.h>
-#else
-#include <strings.h>
-#ifndef strrchr
-#define strrchr rindex
-#endif
-#endif
+#include "xalloc.h"
+#include "xstrndup.h"
+
+/* Return the address of the last file name component of NAME.  If
+   NAME has no relative file name components because it is a file
+   system root, return the empty string.  */
+
+char *
+last_component (char const *name)
+{
+  char const *base = name + FILE_SYSTEM_PREFIX_LEN (name);
+  char const *p;
+  bool saw_slash = false;
+
+  while (ISSLASH (*base))
+    base++;
+
+  for (p = base; *p; p++)
+    {
+      if (ISSLASH (*p))
+	saw_slash = true;
+      else if (saw_slash)
+	{
+	  base = p;
+	  saw_slash = false;
+	}
+    }
+
+  return (char *) base;
+}
+
+
+/* In general, we can't use the builtin `basename' function if available,
+   since it has different meanings in different environments.
+   In some environments the builtin `basename' modifies its argument.
 
-/* Return NAME with any leading path stripped off.  */
+   Return the last file name component of NAME, allocated with
+   xmalloc.  On systems with drive letters, a leading "./"
+   distinguishes relative names that would otherwise look like a drive
+   letter.  Unlike POSIX basename(), NAME cannot be NULL,
+   base_name("") returns "", and the first trailing slash is not
+   stripped.
+
+   If lstat (NAME) would succeed, then { chdir (dir_name (NAME));
+   lstat (base_name (NAME)); } will access the same file.  Likewise,
+   if the sequence { chdir (dir_name (NAME));
+   rename (base_name (NAME), "foo"); } succeeds, you have renamed NAME
+   to "foo" in the same directory NAME was in.  */
 
 char *
-basename (name)
-     char *name;
+base_name (char const *name)
+{
+  char const *base = last_component (name);
+  size_t length;
+
+  /* If there is no last component, then name is a file system root or the
+     empty string.  */
+  if (! *base)
+    return xstrndup (name, base_len (name));
+
+  /* Collapse a sequence of trailing slashes into one.  */
+  length = base_len (base);
+  if (ISSLASH (base[length]))
+    length++;
+
+  /* On systems with drive letters, `a/b:c' must return `./b:c' rather
+     than `b:c' to avoid confusion with a drive letter.  On systems
+     with pure POSIX semantics, this is not an issue.  */
+  if (FILE_SYSTEM_PREFIX_LEN (base))
+    {
+      char *p = xmalloc (length + 3);
+      p[0] = '.';
+      p[1] = '/';
+      memcpy (p + 2, base, length);
+      p[length + 2] = '\0';
+      return p;
+    }
+
+  /* Finally, copy the basename.  */
+  return xstrndup (base, length);
+}
+
+/* Return the length of the basename NAME.  Typically NAME is the
+   value returned by base_name or last_component.  Act like strlen
+   (NAME), except omit all trailing slashes.  */
+
+size_t
+base_len (char const *name)
 {
-  char *base;
+  size_t len;
+  size_t prefix_len = FILE_SYSTEM_PREFIX_LEN (name);
+
+  for (len = strlen (name);  1 < len && ISSLASH (name[len - 1]);  len--)
+    continue;
+
+  if (DOUBLE_SLASH_IS_DISTINCT_ROOT && len == 1
+      && ISSLASH (name[0]) && ISSLASH (name[1]) && ! name[2])
+    return 2;
+
+  if (FILE_SYSTEM_DRIVE_PREFIX_CAN_BE_RELATIVE && prefix_len
+      && len == prefix_len && ISSLASH (name[prefix_len]))
+    return prefix_len + 1;
 
-  base = strrchr (name, '/');
-  return base ? base + 1 : name;
+  return len;
 }