stringprep_utf8_nfkc_normalize(3)

✨ stringprep_utf8_nfkc_normalize(3) — the libidn glow-up page ✨

okay bestie, welcome to the libidn manual, page stringprep_utf8_nfkc_normalize(3). this is the one where Unicode text gets its little makeover. sit down, hydrate, let's go 💖

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🌸 NAME 🌸

stringprep_utf8_nfkc_normalize — the API function. yes that's the whole name. iconic of it. 👑

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🎀 SYNOPSIS 🎀

#include <stringprep.h>

char * stringprep_utf8_nfkc_normalize(const char * str, ssize_t len);

look at her. one include, one function, two arguments. main character energy fr fr ✨

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🦋 ARGUMENTS 🦋

• const char * str — a UTF-8 encoded string. that's it, that's the vibe. it's gotta be UTF-8, no cap.
• ssize_t len — the length of str, in bytes. OR, plot twist, you can pass -1 if str is nul-terminated and you want the function to just figure it out herself. she's smart like that. 💅

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💜 DESCRIPTION 💜

okay so here's the tea: this function converts a string into canonical form. what does that even mean? it means it standardizes messy situations like — and this is the classic example — whether a character with an accent is represented as a base character PLUS a combining accent, or as one single precomposed character. same word, two different byte sequences, and that's a whole problem for comparison and search. 😭

The normalization mode is NFKC (ALL COMPOSE). and the way that NFKC works is it standardizes differences that do not affect the text content, like the accent representation thing we just talked about. so those two different-looking-but-same-meaning encodings become the same thing. slay.

It also standardizes the "compatibility" characters in Unicode. the example in the docs is SUPERSCRIPT THREE getting folded down to the standard form, which in this case is DIGIT THREE. so ³ and 3 are treated as the same thing, which for most text operations they absolutely should be. 💅

⚠️ heads up bestie: formatting information may be lost in this process. that's the trade-off. for most text operations those characters should be considered the same anyway, but like… know what you're signing up for. 🙈

It returns a result with composed forms rather than a maximally decomposed form. so it's giving ✨put-together✨, not ✨spread-out✨.

Return value: a newly allocated string, that is the NFKC normalized form of str. newly allocated means YOU own it now, so free it when you're done. don't be a litterbug. 🫶

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🌈 REPORTING BUGS 🌈

found a bug? not cute, but okay, we fix it together. Report bugs to <help-libidn@gnu.org>.

General guidelines for reporting bugs: https://www.gnu.org/gethelp/

GNU Libidn home page: https://www.gnu.org/software/libidn/

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👑 COPYRIGHT 👑

Copyright © 2002-2026 Simon Josefsson.

Copying and distribution of this file, with or without modification, are permitted in any medium without royalty provided the copyright notice and this notice are preserved. (yes, royalty-free, go forth and distribute, we love a permissive license. periodt. 💖)

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⭐ SEE ALSO ⭐

The full documentation for libidn is maintained as a Texinfo manual. If the info and libidn programs are properly installed at your site, the command

info libidn

should give you access to the complete manual. so like, if you want the whole lore, that's where it lives. 📚

As an alternative you may obtain the manual from:

https://www.gnu.org/software/libidn/manual/

iykyk. 🧚

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and that's the page bestie!! 🎀 this was libidn version 1.44, and the date on this whole thing is the same as always — shoutout to the libidn crew for keeping it real since forever. stay normalized, stay composed, and go free your strings. bye babe 💜🦋✨