1 files changed, 103 insertions, 0 deletions
diff --git a/src/VBox/Runtime/common/path/rtPathRootSpecLen.cpp b/src/VBox/Runtime/common/path/rtPathRootSpecLen.cpp
new file mode 100644
index 00000000..47c140f3
--- /dev/null
+++ b/src/VBox/Runtime/common/path/rtPathRootSpecLen.cpp
@@ -0,0 +1,103 @@
+/* $Id: rtPathRootSpecLen.cpp $ */
+/** @file
+ * IPRT - rtPathRootSpecLen (internal).
+ */
+
+/*
+ * Copyright (C) 2010-2023 Oracle and/or its affiliates.
+ *
+ * This file is part of VirtualBox base platform packages, as
+ * available from https://www.virtualbox.org.
+ *
+ * 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, in version 3 of the
+ * License.
+ *
+ * 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, see <https://www.gnu.org/licenses>.
+ *
+ * The contents of this file may alternatively be used under the terms
+ * of the Common Development and Distribution License Version 1.0
+ * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
+ * in the VirtualBox distribution, in which case the provisions of the
+ * CDDL are applicable instead of those of the GPL.
+ *
+ * You may elect to license modified versions of this file under the
+ * terms and conditions of either the GPL or the CDDL or both.
+ *
+ * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
+ */
+
+
+/*********************************************************************************************************************************
+*   Header Files                                                                                                                 *
+*********************************************************************************************************************************/
+#include "internal/iprt.h"
+#include <iprt/path.h>
+
+#include <iprt/assert.h>
+#include <iprt/ctype.h>
+#include "internal/path.h"
+
+/**
+ * Figures out the length of the root (or drive) specifier in @a pszPath.
+ *
+ * For UNC names, we consider the root specifier to include both the server and
+ * share names.
+ *
+ * @returns The length including all slashes.  0 if relative path.
+ *
+ * @param   pszPath         The path to examine.
+ */
+DECLHIDDEN(size_t) rtPathRootSpecLen(const char *pszPath)
+{
+    /*
+     * If it's an absolute path, threat the root or volume specification as
+     * component 0.  UNC is making this extra fun on OS/2 and Windows as usual.
+     */
+    size_t off = 0;
+    if (RTPATH_IS_SLASH(pszPath[0]))
+    {
+#if defined(RT_OS_OS2) || defined(RT_OS_WINDOWS)
+        if (   RTPATH_IS_SLASH(pszPath[1])
+            && !RTPATH_IS_SLASH(pszPath[2])
+            && pszPath[2])
+        {
+            /* UNC server name */
+            off = 2;
+            while (!RTPATH_IS_SLASH(pszPath[off]) && pszPath[off])
+                off++;
+            while (RTPATH_IS_SLASH(pszPath[off]))
+                off++;
+
+            /* UNC share */
+            while (!RTPATH_IS_SLASH(pszPath[off]) && pszPath[off])
+                off++;
+        }
+        else
+#endif
+        {
+            off = 1;
+        }
+        while (RTPATH_IS_SLASH(pszPath[off]))
+            off++;
+    }
+#if defined(RT_OS_OS2) || defined(RT_OS_WINDOWS)
+    else if (RT_C_IS_ALPHA(pszPath[0]) && pszPath[1] == ':')
+    {
+        off = 2;
+        while (RTPATH_IS_SLASH(pszPath[off]))
+            off++;
+    }
+#endif
+    Assert(!RTPATH_IS_SLASH(pszPath[off]));
+
+    return off;
+}
+