Tag: PCSTR

In previous blog posts, we decoded some Windows SDK string typedefs like PWSTR and PCWSTR. As we already saw, they are basically typedefs for C-style null-terminated wchar_t Unicode UTF-16 string pointers. In particular, the “C” in PCWSTR means that the string is read-only (const).

To recap these typedefs in table form, we have:

Windows SDK Typedef	C/C++ Underlying Type
PWSTR	wchar_t*
PCWSTR	const wchar_t*

Now, as you can imagine, there are also char-based variants of these wchar_t string typedefs. You can easily recognize their names as the char versions do not have the “W” (which stands for WCHAR or equivalently wchar_t): They are PSTR and PCSTR.

As you can see, there is the “STR” part in their names, specifying that these are C-style null-terminated strings. The “P” stands for pointer. So, in table form, they correspond to the following C/C++ underlying types:

Windows SDK Typedef	C/C++ Underlying Type
PSTR	char*
PCSTR	const char*

As expected, the const version, which represents read-only strings, has the letter “C” before “STR”.

These char-based string pointers can be used to represent ASCII strings, strings in some kind of multi-byte encoding, and even UTF-8-encoded strings.

Moreover, as we already saw for the wchar_t versions, another common prefix you can find for them is “LP” instead of just “P” for “pointer”, as in LPSTR and LPCSTR. LPSTR is the same as PSTR; similarly, LPCSTR is the same as PCSTR.

In table form:

Windows SDK Typedef	C/C++ Underlying Type
PSTR	char*
LPSTR	char*
PCSTR	const char*
LPCSTR	const char*