ISWBLANK(3P)

💖 ISWBLANK(3P) 💖

okay bestie, so this one's from the POSIX Programmer's Manual — yes, that whole POSIX Programmer's Manual, and it's ISWBLANK(3P), section 3P, the P standing for "periodt, this is the portable one" 💅

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✨ PROLOG ✨

so like, heads up before we even start: this manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ — so if you're on Linux, go check the corresponding Linux manual page for the actual tea on Linux behavior. orrr the interface might not even be implemented on Linux at all 🙈 vibe check your system first, fr fr.

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🌸 NAME 🌸

iswblank, iswblank_l — test for a blank wide-character code 🦋

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✨ SYNOPSIS ✨

#include <wctype.h>

int iswblank(wint_t wc);
int iswblank_l(wint_t wc, locale_t locale);

look at her. two little functions. so iconic. so small. 🎀

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💅 DESCRIPTION 💅

okay so for iswblank(): 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. This volume of POSIX.1‐2017 defers to the ISO C standard. (basically the C standard is the main character here and POSIX is just being respectful 🫶)

The iswblank() and iswblank_l() functions shall test whether wc is a wide-character code representing a character of class blank — in the current locale for the first one, or in the locale represented by locale for the second one, respectively. see the Base Definitions volume of POSIX.1‐2017, Chapter 7, Locale for the whole lore ✨

The wc argument is a wint_t, and the value of it — 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.

🚨 If the argument has any other value, the behavior is undefined. not "undefined-ish". undefined. no cap.

🚨 Also undefined, and I cannot stress this enough: the behavior is undefined if the locale argument to iswblank_l() is the special locale object LC_GLOBAL_LOCALE, or if it is not a valid locale object handle. do not do that. please. for me. 😭

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🎀 RETURN VALUE 🎀

The iswblank() and iswblank_l() functions shall return non-zero if wc is a blank wide-character code; otherwise, they shall return 0. that's it, that's the whole answer key 💖

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🌈 ERRORS 🌈

No errors are defined. zero. none. not a single one. slay.

The following sections are informative. (translation: the vibe shifts from "rules" to "bonus content" ✨)

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🍓 EXAMPLES 🍓

None. 🙈 (yes really, that's the entire section. she said "no thoughts, head empty.")

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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 roster, iykyk.

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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()
• iswxdigit()
• setlocale()
• uselocale()

and also, from the Base Definitions volume of POSIX.1‐2017:

• Chapter 7, Locale
• <locale.h>
• <wctype.h>

the whole squad. the friend group. the group chat. 🫶

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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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okay and that's the whole page bestie!! 💅✨ brought to you by IEEE/The Open Group, dated 2017, filed under ISWBLANK(3P). now go classify some blank wide characters responsibly 🎀🦋💖