ISXDIGIT(3POSIX)

📦 version 2017a, in debian bookworm, debian trixie, ubuntu jammy, ubuntu noble, ubuntu resolute, ubuntu stonking

🦋 PROLOG 🦋

okay so real talk bestie, this page is part of the POSIX Programmer's Manual (that's the manual name, now you know 💅). But listen — the Linux implementation of this interface may differ, so go check the corresponding Linux manual page for the actual tea on Linux behavior. Or, plot twist, the interface might not even be implemented on Linux at all. 🙈

✨ NAME ✨

isxdigit, isxdigit_l — test for a hexadecimal digit 🧚

🌸 SYNOPSIS 🌸

#include <ctype.h>

int isxdigit(int c);
int isxdigit_l(int c, locale_t locale);

💖 DESCRIPTION 💖

So for isxdigit(): 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 — like, no beef intended fr fr. This volume of POSIX.1‐2017 defers to the ISO C standard, periodt.

The isxdigit() and isxdigit_l() functions shall test whether c is 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 c argument is an int, and the value of it? The application shall ensure it's a character representable as an unsigned char or equal to the value of the macro EOF. If the argument has any other value, the behavior is undefined. 😭 like, undefined undefined. don't do it.

⚠️ also the behavior is undefined if the locale argument to isxdigit_l() is the special locale object LC_GLOBAL_LOCALE or is not a valid locale object handle. no cap, just don't.

⭐ RETURN VALUE ⭐

The isxdigit() and isxdigit_l() functions shall return non-zero if c is a hexadecimal digit; otherwise, they shall return 0. slay, that's it, that's the whole vibe check. 💅

🎀 ERRORS 🎀

No errors are defined. iconic, honestly. ✨

The following sections are informative.

🌈 EXAMPLES 🌈

None. 😭 (sorry bestie, nothing to show off here)

💜 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. iykyk, stick to the approved list.

🫶 RATIONALE 🫶

None.

🔥 FUTURE DIRECTIONS 🔥

None.

👑 SEE ALSO 👑

isalnum(), isalpha(), isblank(), iscntrl(), isdigit(), isgraph(), islower(), isprint(), ispunct(), isspace(), isupper()

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

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 .

and that's the whole page bestie!! brought to you by IEEE/The Open Group, 2017 — mwah, catch you in the next man page 💅✨🦋

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