std::wcsstr(3)

💖 std::wcsstr(3) 💖

okay bestie, so this one's from the C++ Standard Libary manual — yes that's literally how they spell it in the header, not me, don't come for me 💅 — and it's like... the wide-string version of "where's that substring at". Let's get into it 🎀

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✨ NAME ✨

std::wcsstr — literally just std::wcsstr, the name is the name, that's the whole NAME section, iconic of them honestly 🫶

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✨ Synopsis ✨

It lives in the header <cwchar> 🦋

const wchar_t* wcsstr( const wchar_t* dest, const wchar_t* src );
     wchar_t* wcsstr(       wchar_t* dest, const wchar_t* src );

So what does it do?? It finds the first occurrence of the wide string src in the wide string that dest points to. That's the whole vibe check 💅

⚠️ Heads up bestie: the terminating null characters are not compared. Not even a little. So don't be out here expecting null-terminator behaviour, because it's giving "I don't see them" 😭

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✨ Parameters ✨

• dest — pointer to the null-terminated wide string you wanna examine 🔍 (the thing you're searching in, the main character of this operation)
• src — pointer to the null-terminated wide string you're searching for 🌸 (the little icon you're hunting through the crowd)

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✨ Return value ✨

• Pointer to the first character of the found substring inside dest 🎯
• Or a null pointer if no such substring is found — no match, no pointer, that's the deal 🙈
• Special case alert: if src points to an empty string, then dest is returned. Like, immediately. Empty search = you get the whole thing back, we don't even try 💀

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✨ Example ✨

There's a "Run this code" link on the original page btw — this is the code that's sitting behind it 👑

#include <clocale>
#include <cwchar>
#include <iostream>

int main()
{
    wchar_t const* origin = L"アルファ, ベータ, ガンマ, アルファ, ベータ, ガンマ.";
    wchar_t const* target = L"ベータ";
    wchar_t const* result = origin;

    std::setlocale(LC_ALL, "en_US.utf8");
    std::wcout << L"Substring to find: \"" << target << L"\"\n"
               << L"String to search: \"" << origin << L"\"\n\n";

    for (; (result = std::wcsstr(result, target)) != nullptr; ++result)
        std::wcout << L"Found: \"" << result << L"\"\n";
}

look at that loop bestie — it keeps calling std::wcsstr on the result and bumping ++result so it doesn't just find the same one forever. that's the trick, that's the whole trick 🧚

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✨ Possible output ✨

Substring to find: "ベータ"
String to search: "アルファ, ベータ, ガンマ, アルファ, ベータ, ガンマ."

Found: "ベータ, ガンマ, アルファ, ベータ, ガンマ."
Found: "ベータ, ガンマ."

two matches, found in order, slay ✨ note how each found line prints from the match all the way to the end of the string, because that's what a pointer to the first char of the substring is 😌

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✨ See also ✨

• find — finds the first occurrence of the given substring (public member function of std::basic_string<CharT,Traits,Allocator>) 💜 the C++ string version, the comfy one
• strstr — finds the first occurrence of a substring of characters (function) 🔥 the narrow-char sibling, same energy, smaller chars
• wcschr — finds the first occurrence of a wide character in a wide string (function) 🦋 singular, one char only
• wcsrchr — finds the last occurrence of a wide character in a wide string (function) ⭐ note the r — it's backwards, it's the last one
• C documentation for wcsstr — the C version is out there too, go look if you want 📚

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okay that's the whole page, no cap 🫶 and for the record this came from http://cppreference.com and it's dated 2024.06.10, so if anything's changed since then, blame the calendar not me 😭💖 go find your substrings bestie, periodt 💅✨