(This is the documentation for SDL3, which is the current stable version. SDL2 was the previous version!)

SDL_utf8strnlen

Count the number of codepoints in a UTF-8 string, up to n bytes.

Header File

Syntax

size_t SDL_utf8strnlen(const char *str, size_t bytes);

Function Parameters

const char *	str	The null-terminated UTF-8 string to read. Must not be NULL.
size_t	bytes	The maximum amount of bytes to count.

Return Value

(size_t) Returns The length (in codepoints, excluding the null terminator) of src but never more than maxlen.

Remarks

Counts the codepoints, not bytes, in str, excluding the null terminator.

If you need to count the bytes in a string instead, consider using SDL_strnlen().

The counting stops at bytes bytes (not codepoints!). This seems counterintuitive, but makes it easy to express the total size of the string's buffer.

Since this handles Unicode, it expects the strings to be well-formed UTF-8 and not a null-terminated string of arbitrary bytes. Bytes that are not valid UTF-8 are treated as Unicode character U+FFFD (REPLACEMENT CHARACTER), so a malformed or incomplete UTF-8 sequence might increase the count by several replacement characters.

Thread Safety

It is safe to call this function from any thread.

Version

This function is available since SDL 3.1.3.