DUPLOCALE(3POSIX)

💖 duplocale(3POSIX) — the POSIX Programmer's Manual, but make it cute 💖

okay bestie, quick vibe check before we dive in: this page lives in the POSIX Programmer's Manual. That means the Linux version of this function might lowkey be different (go check the matching Linux man page for the deets on Linux behavior), or honestly the whole thing might just not be implemented on Linux at all. 🙈 Just so you know what you're walking into.

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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 🌸

duplocale — duplicate a locale object. That's it. That's the whole job. She copies. 💅

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🎀 SYNOPSIS 🎀

#include <locale.h>

locale_t duplocale(locale_t locobj);

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🦋 DESCRIPTION 🦋

so the duplocale() function shall create a duplicate copy of the locale object referenced by the locobj argument. A whole clone. Copy-paste but legal. 👑

If the locobj argument is LC_GLOBAL_LOCALE, then duplocale() shall create a new locale object containing a copy of the global locale — the one determined by the setlocale() function. So like, if you hand it the global vibe, it hands you back a real, tangible locale object of that same vibe. ✨

💀 the behavior is undefined if the locobj argument is not a valid locale object handle. Not "it errors", not "it's fine", just undefined. Do not pass garbage. Do not test the universe. Periodt.

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💅 RETURN VALUE 💅

Upon successful completion, the duplocale() function shall return a handle for a new locale object. She ate, she delivered, you got a handle. 🎉

Otherwise, duplocale() shall return (locale_t)0 and set errno to indicate the error. Sad girl hours. 😭

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🌈 ERRORS 🌈

The duplocale() function shall fail if:

• ENOMEM — There is not enough memory available to create the locale object or load the locale data. Bestie is out of RAM, and there is nothing anyone can do about it.

The following sections are informative.

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🌟 EXAMPLES 🌟

🧚 Constructing an Altered Version of an Existing Locale Object

The following example shows a code fragment to create a slightly altered version of an existing locale object. The function takes a locale object and a locale name, and it replaces the LC_TIME category data in the locale object with that from the named locale.

#include <locale.h>
...

locale_t
with_changed_lc_time (locale_t obj, const char *name)
{

    locale_t retval = duplocale (obj);
    if (retval != (locale_t) 0)
    {
        locale_t changed = newlocale (LC_TIME_MASK, name, retval);
        if (changed == (locale_t) 0)
            /* An error occurred. Free all allocated resources. */
            freelocale (retval);
        retval = changed;
    }
    return retval;
}

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💜 APPLICATION USAGE 💜

The use of the duplocale() function is recommended for situations where a locale object is being used in multiple places, and it is possible that the lifetime of the locale object might end before all uses are finished. Translation: she might get yeeted out of existence while people are still using her, so you clone her first. Protect your faves. 🫶

Another reason to duplicate a locale object is if a slightly modified form is needed. This can be achieved by a call to newlocale() following the duplocale() call. Clone first, then customize. It's giving glow-up arc. ✨

As with the newlocale() function, handles for locale objects created by the duplocale() function should be released by a corresponding call to freelocale(). Clean up after yourself, no cap. 🧹

The duplocale() function can also be used in conjunction with uselocale((locale_t)0). This returns the locale in effect for the calling thread, but can have the value LC_GLOBAL_LOCALE. Passing LC_GLOBAL_LOCALE to functions such as isalnum_l() results in undefined behavior, but applications can convert it into a usable locale object by using duplocale(). So basically: uselocale((locale_t)0) might hand you the global vibe, and the global vibe is not welcome at functions like isalnum_l() — but one lil duplocale() and boom, you've got a legit locale object you can actually pass around. Main character move. 👑

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⭐ RATIONALE ⭐

None.

(Yeah. Nothing. Not a single word. Iconic of her honestly. 💀)

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🍓 FUTURE DIRECTIONS 🍓

None.

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🔥 SEE ALSO 🔥

• freelocale()
• newlocale()
• uselocale()

The Base Definitions volume of POSIX.1‐2017, <locale.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!! this one's from IEEE/The Open Group, 2017 — thanks for reading, mwah, go duplicate a locale responsibly 💖✨🎀🦋