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11.28 isascii ¶

Removed in POSIX.1-2024. POSIX.1-2017 specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isascii.html

Gnulib module: ctype

Portability problems fixed by Gnulib:

• This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

• This function is removed in POSIX.1-2024.

Note: This function’s behaviour depends on the locale, but requires special handling for the multibyte characters that occur in strings in locales with MB_CUR_MAX > 1 (this includes all the common UTF-8 locales). There are two alternative APIs:

c_isascii ¶

This function operates in a locale independent way and returns true only for ASCII characters. It is provided by the Gnulib module ‘c-ctype’.

mb_isascii ¶

This function operates in a locale dependent way, on multibyte characters. It is provided by the Gnulib module ‘mbchar’.