@node isascii @section @code{isascii} @findex isascii POSIX specification:@* @url{https://pubs.opengroup.org/onlinepubs/9699919799/functions/isascii.html} Gnulib module: ctype Portability problems fixed by Gnulib: @itemize @item This function cannot be called from plain inline or extern inline functions on some platforms: OS X 10.8. @end itemize Portability problems not fixed by Gnulib: @itemize @end itemize Note: This function's behaviour depends on the locale, but requires special handling for the multibyte characters that occur in strings in locales with @code{MB_CUR_MAX > 1} (this includes all the common UTF-8 locales). There are two alternative APIs: @table @code @item c_isascii This function operates in a locale independent way and returns true only for ASCII characters. It is provided by the Gnulib module @samp{c-ctype}. @item mb_isascii This function operates in a locale dependent way, on multibyte characters. It is provided by the Gnulib module @samp{mbchar}. @end table