memrchr(3)

💖 memrchr(3) — bestie edition 💖

okay so literally the whole vibe of this page is memrchr — the memory rear-search character function — and yes it's a Library Functions Manual entry, and yes it lives in your friendly neighborhood Standard C library (libc, and you link it with -lc). no cap. 🦋

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✨ NAME ✨

memrchr — memory rear-search character. that's it, that's the girl. she finds a character in memory but backwards. 🔥

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📚 LIBRARY 📚

Standard C library (libc, -lc)

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🎀 SYNOPSIS 🎀

#define _GNU_SOURCE  // See feature_test_macros(7)
#include <string.h>  // see memory.h(3head)

void *memrchr(size_t n;
              const void s[n], int c, size_t n);

ngl bestie, you have to define _GNU_SOURCE before you pull in the header, otherwise she simply will not appear. it's giving gatekept. 🙈 (see feature_test_macros(7) for the lore, and memory.h(3head) for the header situation.)

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🌸 DESCRIPTION 🌸

okay so memrchr() is basically memchr(3)'s iconic sibling 🫶 — except instead of starting at the front and walking forward, she starts at the end of the n bytes that s points to, and she searches backward. main character energy honestly. 💅

• memchr(3) → forward from the beginning (walking in normally, casual) ✨
• memrchr() → backward from the end (making an entrance) 👑

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🍓 RETURN VALUE 🍓

no thoughts, just vibes — and also: see memchr(3). she returns the exact same way her sibling does, no need to reinvent the wheel here. 😭

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💜 ATTRIBUTES 💜

for the full explanation of what these words even mean, check out attributes(7). here's the tea:

• memrchr() — Thread safety: MT-Safe ✅

that's right girls, she's MT-Safe. thread-safe queen. go off. 👑

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⭐ STANDARDS ⭐

GNU.

sobbing softly, she is not in POSIX. if you need portable, this is not your girl. fr fr. 💀

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🦋 HISTORY 🦋

she was born in glibc 2.2. a legend since day one. periodt. 🎀

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🌈 SEE ALSO 🌈

• memory.h(3head)
• memchr(3)

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wrap-up check-in 💖 — this whole page is from Linux man-pages 6.20, dated 2026-08-10, and that's the <rainbow>memrchr(3)</rainbow> ✨ <rainbow>memrchr(3)</rainbow> ✨ header-and-footer realness, bestie. stan a thread-safe backwards searcher. bye mwah 💅🫶🌸