Compare two wide strings, case-insensitively, up to a number of wchar_t.
Defined in <SDL3/SDL_stdinc.h>
int SDL_wcsncasecmp(const wchar_t *str1, const wchar_t *str2, size_t maxlen);| const wchar_t * | str1 | the first string to compare. NULL is not permitted! |
| const wchar_t * | str2 | the second string to compare. NULL is not permitted! |
| size_t | maxlen | the maximum number of wchar_t values to compare. |
(int) Returns less than zero if str1 is "less than" str2, greater than zero if str1 is "greater than" str2, and zero if the strings match exactly.
This will work with Unicode strings, using a technique called "case-folding" to handle the vast majority of case-sensitive human languages regardless of system locale. It can deal with expanding values: a German Eszett character can compare against two ASCII 's' chars and be considered a match, for example. A notable exception: it does not handle the Turkish 'i' character; human language is complicated!
Depending on your platform, "wchar_t" might be 2 bytes, and expected to be UTF-16 encoded (like Windows), or 4 bytes in UTF-32 format. Since this handles Unicode, it expects the string to be well-formed and not a null-terminated string of arbitrary bytes. Characters that are not valid UTF-16 (or UTF-32) are treated as Unicode character U+FFFD (REPLACEMENT CHARACTER), which is to say two strings of random bits may turn out to match if they convert to the same amount of replacement characters.
Note that while this function might deal with variable-sized characters, maxlen specifies a wchar limit! If the limit lands in the middle of a multi-byte UTF-16 sequence, it may convert a portion of the final character to one or more Unicode character U+FFFD (REPLACEMENT CHARACTER) so as not to overflow a buffer.
maxlen specifies a maximum number of wchar_t values to compare; if the strings match to this number of wchar_t (or both have matched to a null-terminator character before this number of bytes), they will be considered equal.
It is safe to call this function from any thread.
This function is available since SDL 3.1.3.