iswxdigit(3)

✨ iswxdigit(3) — the wide-char hex digit vibe check ✨

okay bestie, so this is a page from the Library Functions Manual, and today's main character is iswxdigit. it's giving "is this wide character a hex digit or not" and honestly? iconic. 🎀

---

🌸 NAME 🌸

iswxdigit — test for hexadecimal digit wide character

📚 LIBRARY 📚

Standard C library (libc, -lc) — the og, the blueprint, the moment 💅

🧚 SYNOPSIS 🧚

#include <wctype.h>

int iswxdigit(wint_t wc);

💖 DESCRIPTION 💖

okay so iswxdigit() is literally the wide-character equivalent of the isxdigit(3) function. no cap. it tests whether wc is a wide character that belongs to the wide-character class "xdigit". 🦋

The wide-character class "xdigit" is a subclass of the wide-character class "alnum", and therefore also a subclass of the wide-character class "graph" and of the wide-character class "print". it's giving family tree, it's giving inheritance, we love a lineage moment 👑

Being a subclass of the wide-character class "print", the wide-character class "xdigit" is disjoint from the wide-character class "cntrl". not them being total strangers 🙈

Being a subclass of the wide-character class "graph", the wide-character class "xdigit" is disjoint from the wide-character class "space" and its subclass "blank". no overlap, no crossover episode, periodt ✋

Being a subclass of the wide-character class "alnum", the wide-character class "xdigit" is disjoint from the wide-character class "punct". different worlds fr fr 💫

and the wide-character class "xdigit" always contains at least the letters 'A' to 'F', 'a' to 'f' and the digits '0' to '9'. the founding members. the girlies. the core four (okay, the core twenty-two) 🍓

🔥 RETURN VALUE 🔥

• iswxdigit() returns nonzero if wc is a wide character belonging to the wide-character class "xdigit". ✅
• Otherwise, it returns zero. 💀

🎀 ATTRIBUTES 🎀

ngl bestie, for the full explanation of the terms used in this section, go peek at attributes(7) — it's the lore doc 💜

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

so yeah — thread safety is MT-Safe locale. write that down. 📝

⭐ STANDARDS ⭐

C11, POSIX.1-2008. certified, approved, notarised, slay ✨

🌈 HISTORY 🌈

POSIX.1-2001, C99. a classic. an elder. we respect our ancestors 🫶

👑 NOTES 👑

The behavior of iswxdigit() depends on the LC_CTYPE category of the current locale. so like… locale matters. always has, always will. iykyk 🦋

💅 SEE ALSO 💅

• iswctype(3)
• isxdigit(3)

---

Linux man-pages 6.20, dated 2026-02-08, and this page is iswxdigit(3) — mwah, that's the whole thing, go hex-ify something gorgeous 💖🎀✨