SDL_strcasestr(3)

💖 SDL_strcasestr — the "where's my substring tho" girlie 💖

okay bestie, so this one lives in the SDL3 FUNCTIONS lineup, and her whole personality is: find the first place a substring shows up inside a bigger string, and do it case-insensitively. no cap. 🎀

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✨ NAME ✨

SDL_strcasestr — search a UTF-8 string for the first instance of a specific substring, case-insensitively.

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✨ SYNOPSIS ✨

#include <SDL3/SDL_stdinc.h>

char * SDL_strcasestr(const char *haystack, const char *needle);

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🌈 DESCRIPTION 🌈

so this bad girl works with Unicode strings, using a technique called "case-folding" — and she uses it to handle the vast majority of case-sensitive human languages regardless of system locale. she's not checking your locale settings, she simply does not care. 👑

she can also deal with expanding values, which is the unhinged part: a German Eszett character can compare against two ASCII 's' chars and still be considered a match. like, one character eating two. iconic behavior honestly. 💅

but there's a notable exception, and I need you to hear me on this: she does not handle the Turkish 'i' character. human language is complicated! 😭

and since she's doing Unicode, she expects the strings to be well-formed UTF-8 — not just a null-terminated string of arbitrary bytes. any bytes that aren't valid UTF-8 get treated as Unicode character U+FFFD (REPLACEMENT CHARACTER). which means, fr fr, two strings of random bits may turn out to match if they convert to the same amount of replacement characters. chaos! 🫠

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🎀 FUNCTION PARAMETERS 🎀

• haystack — the string to search. must not be NULL. 🚫
• needle — the string to search for. must not be NULL. 🚫

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⭐ RETURN VALUE ⭐

returns a pointer to the first instance of needle in the string, or NULL if it wasn't found. that's it, that's the tea. 🍓

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🧚 THREAD SAFETY 🧚

it is safe to call this function from any thread. go wild, multithreaded bestie, she can hang. 🔥

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💜 AVAILABILITY 💜

this function has been available since SDL 3.2.0. she's not new-new, but she's not ancient either. ✨

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and that's the whole page, bestie!! 🦋 this one came straight from Simple Directmedia Layer, version SDL 3.4.18, and it's the SDL_strcasestr(3) page — go forth and case-fold responsibly 💖🌸👑