wcsstr(3)

💖 wcsstr(3) — the wide-char girlies' substring finder 💖

okay so bestie, welcome to the wcsstr(3) page from the Library Functions Manual — yes it lives in section 3, we love a library-call moment. pull up a chair, grab a boba, and let's find some substrings ✨

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🌸 NAME 🌸

wcsstr — locate a substring in a wide-character string

📚 LIBRARY 📚

Standard C library (libc, -lc)

✨ SYNOPSIS ✨

#include <wchar.h>

wchar_t *wcsstr(const wchar_t *haystack, const wchar_t *needle);

🧚 DESCRIPTION 🧚

so wcsstr() is literally the wide-character version of strstr(3), no cap. it's giving same energy, wider chars 💅

what it does: it searches for the first occurrence of the wide-character string needle — and bestie, note that the terminating null wide character (L'\0') of needle is not included in the search — as a substring inside the wide-character string haystack. iconic behaviour honestly 🫶

think of it like: haystack is the group chat, needle is the message you're scrolling for, and wcsstr() is you, finding it. main character energy 🔥

🎀 RETURN VALUE 🎀

wcsstr() hands you back a pointer to the first occurrence of needle inside haystack. slay.

but if needle doesn't occur as a substring in haystack at all? it returns NULL. 💀 (sad, but predictable, we respect it.)

⭐ special case alert ⭐ bestie listen up: if needle is the empty wide-character string, the return value is always haystack itself. yes, always. that's the rule. periodt.

👑 ATTRIBUTES 👑

for the full explanation of what these terms even mean, go peek at attributes(7). here's the vibe check for this one:

• Interface: wcsstr()
• Attribute: Thread safety
• Value: MT-Safe

(translation: it's thread-safe, she's stable, she's trustworthy 🦋)

🌈 STANDARDS 🌈

C11, POSIX.1-2008. certified, official, on the syllabus 📖

🕰️ HISTORY 🕰️

POSIX.1-2001, C99. she's been around, she's got lore 🌟

🔍 SEE ALSO 🔍

• strstr(3)
• wcschr(3)

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and that's the whole page, bestie — go forth and find your substrings 💜

Linux man-pages 6.20 · last touched 2026-02-08 · mwah, ily, bye 🍓🧚✨