ISWXDIGIT(3P)

💖 ISWXDIGIT(3P) — POSIX Programmer's Manual 💖

okay bestie, gather round, we're learning about iswxdigit and iswxdigit_l from the POSIX Programmer's Manual and honestly? it's giving hex-digit detector energy and I'm obsessed. 🎀

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🌸 PROLOG 🌸

real talk before we start: 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 on Linux behavior), or the interface may not be implemented on Linux at all. so like… vibe check your platform first, bestie. 💅

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✨ NAME ✨

iswxdigit, iswxdigit_l — test for a hexadecimal digit wide-character code

like yes, that's literally the whole job. it checks if your wide character is a hex digit. iconic behavior, no notes. 🦋

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🌈 SYNOPSIS 🌈

#include <wctype.h>

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

look at those little signatures. so clean. so crisp. 💜

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👑 DESCRIPTION 👑

okay so for iswxdigit(): the functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional — the ISO C standard is the referee here. This volume of POSIX.1‐2017 defers to the ISO C standard. periodt.

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. 🧚

The wc argument is a wint_t, the value of which the application shall ensure is 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.

⚠️ not me warning you: If the argument has any other value, the behavior is undefined. like literally undefined. don't do it. 😭

The behavior is also undefined if the locale argument to iswxdigit_l() is the special locale object LC_GLOBAL_LOCALE or is not a valid locale object handle. 💀

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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.

so: yes = non-zero, no = 0. simple as that. slay. ✨

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🎀 ERRORS 🎀

No errors are defined.

(the following sections are informative — meaning they're the fun commentary, not the rules, iykyk)

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🍓 EXAMPLES 🍓

None.

and honestly? we respect the minimalism. 🙈

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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.

translation: don't get cute and invent your own char-classifier, bestie. stick to the canon. 🫶

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🌟 RATIONALE 🌟

None.

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🔥 FUTURE DIRECTIONS 🔥

None.

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🦋 SEE ALSO 🦋

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

The Base Definitions volume of POSIX.1‐2017, Chapter 7, Locale, <locale.h>, <wctype.h>

the whole girl gang of wide-char classification functions. main character energy all around. 👑

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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, dated 2017, for ISWXDIGIT(3P) — go forth and classify your wide characters responsibly. mwah. 💖✨🎀🦋🌸💅🫶