| @c Documentation of gnulib module 'c-ctype'. |
| |
| @c Copyright (C) 2008--2020 Free Software Foundation, Inc. |
| |
| @c Permission is granted to copy, distribute and/or modify this document |
| @c under the terms of the GNU Free Documentation License, Version 1.3 or |
| @c any later version published by the Free Software Foundation; with no |
| @c Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A |
| @c copy of the license is at <https://www.gnu.org/licenses/fdl-1.3.en.html>. |
| |
| The @code{c-ctype} module contains functions operating on single-byte |
| characters, like the functions in @code{<ctype.h>}, that operate as if the |
| locale encoding was ASCII. (The "C" locale on many systems has the locale |
| encoding "ASCII".) |
| |
| The functions are: |
| @smallexample |
| extern bool c_isascii (int c); |
| |
| extern bool c_isalnum (int c); |
| extern bool c_isalpha (int c); |
| extern bool c_isblank (int c); |
| extern bool c_iscntrl (int c); |
| extern bool c_isdigit (int c); |
| extern bool c_islower (int c); |
| extern bool c_isgraph (int c); |
| extern bool c_isprint (int c); |
| extern bool c_ispunct (int c); |
| extern bool c_isspace (int c); |
| extern bool c_isupper (int c); |
| extern bool c_isxdigit (int c); |
| |
| extern int c_tolower (int c); |
| extern int c_toupper (int c); |
| @end smallexample |
| |
| These functions assign properties only to ASCII characters. |
| |
| The @var{c} argument can be a @code{char} or @code{unsigned char} value, |
| whereas the corresponding functions in @code{<ctype.h>} take an argument |
| that is actually an @code{unsigned char} value. |
| |
| The @code{c_is*} functions return @samp{bool}, where the corresponding |
| functions in @code{<ctype.h>} return @samp{int} for historical reasons. |
| |
| Note: The @code{<ctype.h>} functions support only unibyte locales. |
