legacy_coding(3NCURSES)

💖 legacy_coding — the ncurses manual page, but make it make sense 💖

okay bestie, pull up a chair, because we're talking about legacy_coding(3NCURSES) — a lil library-calls page from ncurses that lets you tell curses to stop being soooo judgy about what counts as a "printable" character. yes this is real. yes it's niche. no we are not skipping anything. 💅

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✨ NAME ✨

use_legacy_coding — override curses locale encoding checks 🫶

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✨ SYNOPSIS ✨

#include <curses.h>

int use_legacy_coding(int level);

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✨ DESCRIPTION ✨

so use_legacy_coding is an ncurses extension to the curses library (not standard curses, we'll get to that 😌), and what it does is let you customize how unctrl(3NCURSES) behaves. specifically, it suppresses the isprint(3)-based checks inside the library — the ones that would normally make nonprinting characters get rendered in a visible form.

and the way it does that? it only messes with byte-wide characters that have the most significant bit set. nothing else. that's the whole scope, periodt. 🌸

the level parameter is the whole personality of this function, and it goes like this:

• 0 — the library functions normally, rendering nonprinting characters as described in unctrl(3NCURSES).
• 1 — the library ignores isprint for codes in the range 160-255.
• 2 — the library ignores isprint for codes in the range 128-255. It also modifies the output of unctrl(3NCURSES), showing codes in the range 128-159 as is. 👑

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✨ RETURN VALUE ✨

if the curses screen has not been initialized, or if the level parameter is out of range, use_legacy_coding returns ERR. 😭

otherwise? it returns the previous level. cute little time capsule, honestly. 🎀

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✨ EXTENSIONS ✨

use_legacy_coding is an ncurses extension. that's it, that's the section. iykyk. 💜

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✨ PORTABILITY ✨

apps that use ncurses extensions should condition their use on the visibility of the NCURSES_VERSION preprocessor macro. like, don't just rawdog it across systems, bestie. 🙈

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✨ HISTORY ✨

ncurses 5.6 (2006) introduced use_legacy_coding to support lynx(1)'s font-switching feature. so yes, this function exists because a text browser needed to switch fonts. iconic origin story, no notes. 🌈

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✨ AUTHORS ✨

Thomas Dickey 👑

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✨ SEE ALSO ✨

• unctrl(3NCURSES)

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and that's the whole page!! this was ncurses 6.6, dated 2024-09-14, and honestly? she ate. go forth and set your legacy coding levels responsibly 🦋💖✨