ISWXDIGIT(3POSIX)

💅 ISWXDIGIT(3POSIX) — the POSIX Programmer's Manual, bestie edition 🎀

okay so real talk, this whole page lives inside the POSIX Programmer's Manual. Heads up though: the Linux version of this interface might be a lil different (go check the matching Linux manual page for the deets), or honestly it might not even be implemented on Linux at all. Not me delivering bad news in paragraph one 😭

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✨ PROLOG ✨

This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

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🌸 NAME 🌸

iswxdigit, iswxdigit_l — bestie, these two test for a hexadecimal digit wide-character code 💖

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🦋 SYNOPSIS 🦋

#include <wctype.h>

int iswxdigit(wint_t wc);
int iswxdigit_l(wint_t wc, locale_t locale);

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💜 DESCRIPTION 💜

So for iswxdigit(): the functionality described on this reference page is aligned with the ISO C standard. If anything here conflicts with the requirements in the ISO C standard, that conflict is genuinely unintentional — this volume of POSIX.1‐2017 defers to the ISO C standard, periodt. No drama, no fighting, the ISO C standard wins.

The iswxdigit() and iswxdigit_l() functions shall test whether wc is a wide-character code representing a character of class xdigit in the current locale, or in the locale represented by locale, respectively — see the Base Definitions volume of POSIX.1‐2017, Chapter 7, Locale. Yes, they're twins, one just takes a locale as a lil extra 🫶

Now the wc argument is a wint_t, and the value of it? The application shall ensure it's a wide-character code corresponding to a valid character in the locale used by the function, or equal to the value of the macro WEOF. If the argument has any other value, the behavior is undefined 💀 like please don't.

⚠️ Also, the behavior is undefined if the locale argument to iswxdigit_l() is the special locale object LC_GLOBAL_LOCALE, or if it's not a valid locale object handle. Do not pass either of those. I'm begging. 🙈

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⭐ RETURN VALUE ⭐

The iswxdigit() and iswxdigit_l() functions shall return non-zero if wc is a hexadecimal digit wide-character code; otherwise, they shall return 0. Simple as that, no notes 💅

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🎀 ERRORS 🎀

No errors are defined. Zero. None. A totally chill function.

The following sections are informative (iykyk — that means they're the vibe, not the rules).

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🌈 EXAMPLES 🌈

None. Nothing to show you bestie, sorry 😭

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🔥 APPLICATION USAGE 🔥

To ensure applications portability, especially across natural languages, only these functions and the functions in the reference pages listed in the SEE ALSO section should be used for character classification. Like, stay in your lane, use the approved squad 👑

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👑 RATIONALE 👑

None. We don't explain ourselves, we just slay.

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🧚 FUTURE DIRECTIONS 🧚

None. The future is bright and unchanging ✨

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💖 SEE ALSO 💖

• iswalnum()
• iswalpha()
• iswcntrl()
• iswctype()
• iswdigit()
• iswgraph()
• iswlower()
• iswprint()
• iswpunct()
• iswspace()
• iswupper()
• setlocale()
• uselocale()

Also the Base Definitions volume of POSIX.1‐2017, Chapter 7, Locale, plus <locale.h> and <wctype.h> 🌸

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🍓 COPYRIGHT 🍓

Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .

Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source files to man page format. To report such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .

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and that's the whole page, bestie — brought to you by IEEE/The Open Group, 2017, on the ISWXDIGIT(3POSIX) page itself. mwah, go hex-decode something iconic 💖✨