RtlGetLengthWithoutLastFullDosOrNtPathElement

Gets the length of a path discounting the last full part

Syntax

NTSTATUS WINAPI RtlGetLengthWithoutLastFullDosOrNtPathElement (
    ULONG flags,
    PUNICODE_STRING pStr,
    PULONG pOutLen
)

Parameters

Return Value

STATUS_SUCCESS if everything's good, an error code is not

Example

#include <windows.h>
#include <stdio.h>
#include <string.h>
typedef NTSTATUS (NTAPI*pfnRtlLengthWoutLastPart)(ULONG, PCUNICODE_STRING, PULONG);

int __cdecl wmain(int argc, wchar_t** argv)
{
    HMODULE hNt = GetModueHandle(L"ntdll.dll");
    pfnRtlLengthWoutLastPart RtlLengthWoutLastPart = (pfnRtlLengthWoutLastPart)GetProcAddress(hNt, "RtlGetLengthWithoutLastFullDosOrNtPathElement");
    WCHAR tests[][30] = {
        L"C:\\",
        L"D:\\Test\\hello.ext",
        L"\\\\?\\C:",
        L"\\??\\UNC\\Mytest",
        L"Z:/forwardslash/",
        L"Z:/forwardslash/test",
        L"\\SystemRoot\\ntdll.dll"
    };
    for(int i = 0; i < ARRAYSIZE(tests); ++i)
    {
        UNICODE_STRING usStr = {wcslen(tests[i]) * sizeof(WCHAR), sizeof(tests[i]), tests[i]};
        ULONG length = 0;
        RtlLengthWoutLastPart(0, &usStr, &length);
        wprintf(L"Length for \"%s\": %lu\n", tests[i], length);
    }
    return 0;
}

OUTPUT
------
Length for "C:\": 0
Length for "D:\Test\hello.ext": 8
Length for "\\?\C:": 0
Length for "\??\UNC\Mytest": 8
Length for "Z:/forwardslash/": 3
Length for "Z:/forwardslash/test": 16
Length for "\SystemRoot\ntdll.dll": 12