wcscasecmp(3)

💖 wcscasecmp(3) — the wide-char girlies who don't care about case 💖

okay bestie, sit down, hydrate, because we're talking about wcscasecmp and wcsncasecmp — two absolute icons from the Library Functions Manual of the wcscasecmp(3) page. they compare two wide-character strings and just. don't. care. about case. lowercase, uppercase, whatever, they're not judging 💅

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✨ NAME ✨

wcscasecmp, wcsncasecmp — compare two wide-character strings, ignoring case

like, fr fr, that's the whole vibe. two wide strings walk in, case gets ignored, somebody's declared greater. iconic behavior.

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🎀 LIBRARY 🎀

Standard C library (libc, -lc)

so you gotta link the -lc bestie, that's where the magic lives 🌸

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🦋 SYNOPSIS 🦋

#include <wchar.h>

int wcscasecmp(const wchar_t *s1, const wchar_t *s2);
int wcsncasecmp(const wchar_t s1[], const wchar_t s2[], size_t n);

💜 Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

wcscasecmp(), wcsncasecmp():

• Since glibc 2.10:
  • _POSIX_C_SOURCE >= 200809L
• Before glibc 2.10:
  • _GNU_SOURCE

so depending on how ancient your glibc is, you either flex _POSIX_C_SOURCE >= 200809L or you go full old-school and define _GNU_SOURCE. glow-up requirements, basically ✨

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🌈 DESCRIPTION 🌈

so wcscasecmp() is literally the wide-character equivalent of the strcasecmp(3) function. she takes the wide-character string pointed to by s1 and the wide-character string pointed to by s2 and compares them, ignoring case differences — shoutout to towupper(3) and towlower(3) for handling that part, they're the ones doing the case-flipping behind the scenes 🫶

and wcsncasecmp()? she's the same energy, the wide-character equivalent of strncasecmp(3), except she compares no more than n wide characters of s1 and s2. boundaries, bestie. she has them. n is the limit and she respects it 💅

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👑 RETURN VALUE 👑

wcscasecmp() and wcsncasecmp() hand you back an integer that is:

• less than zero → s1 is, after ignoring case, found to be less than s2
• equal to zero → s1 matches s2
• greater than zero → s1 is, after ignoring case, found to be greater than s2

that's it. that's the whole report card. no cap 📝

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🔥 ATTRIBUTES 🔥

for the full explanation of what these terms even mean, go peek at attributes(7) — she explains everything, she's the source.

• wcscasecmp(), wcsncasecmp() — Thread safety: MT-Safe locale

so yes, thread-safe, but she's locale-dependent about it — MT-Safe locale is the exact vibe, don't forget the locale part 😭

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⭐ STANDARDS ⭐

POSIX.1-2008.

certified, standardized, official. she said "I'm in the spec" and she was right 💖

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🧚 HISTORY 🧚

glibc 2.1.

she's been here since glibc 2.1, an elder stateswoman of wide-char case-insensitive comparison, and she's still serving 🌸

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🍓 NOTES 🍓

the behavior of wcscasecmp() depends on the LC_CTYPE category of the current locale.

⚠️ bestie this matters — swap your locale, swap her whole attitude. LC_CTYPE is running the show here, so set it with intention, mwah 💋

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🌟 SEE ALSO 🌟

• strcasecmp(3)
• wcscmp(3)

go read those too, they're her cousins and they also ate ✨

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okay that's the whole page, you're officially educated 💅 and one last thing — this lil masterpiece lives in Linux man-pages 6.20, dated 2026-02-08, page wcscasecmp(3). so when you cite her, cite her correctly bestie 🎀 bye, ily, go compare some wide strings ✨🦋💖