'\" t .\" Copyright (c) Bruno Haible .\" .\" SPDX-License-Identifier: GPL-2.0-or-later .\" .\" References consulted: .\" GNU glibc-2 source code and manual .\" Dinkumware C library reference http://www.dinkumware.com/ .\" OpenGroup's Single UNIX specification http://www.UNIX-systems.org/online.html .\" ISO/IEC 9899:1999 .\" .TH iswdigit 3 2024-05-02 "Linux man-pages 6.9.1" .SH NAME iswdigit \- test for decimal digit wide character .SH LIBRARY Standard C library .RI ( libc ", " \-lc ) .SH SYNOPSIS .nf .B #include .P .BI "int iswdigit(wint_t " wc ); .fi .SH DESCRIPTION The .BR iswdigit () function is the wide-character equivalent of the .BR isdigit (3) function. It tests whether .I wc is a wide character belonging to the wide-character class "digit". .P The wide-character class "digit" is a subclass of the wide-character class "xdigit", and therefore also a subclass of the wide-character class "alnum", of the wide-character class "graph" and of the wide-character class "print". .P Being a subclass of the wide character class "print", the wide-character class "digit" is disjoint from the wide-character class "cntrl". .P Being a subclass of the wide-character class "graph", the wide-character class "digit" is disjoint from the wide-character class "space" and its subclass "blank". .P Being a subclass of the wide-character class "alnum", the wide-character class "digit" is disjoint from the wide-character class "punct". .P The wide-character class "digit" is disjoint from the wide-character class "alpha" and therefore also disjoint from its subclasses "lower", "upper". .P The wide-character class "digit" always contains exactly the digits \[aq]0\[aq] to \[aq]9\[aq]. .SH RETURN VALUE The .BR iswdigit () function returns nonzero if .I wc is a wide character belonging to the wide-character class "digit". Otherwise, it returns zero. .SH ATTRIBUTES For an explanation of the terms used in this section, see .BR attributes (7). .TS allbox; lbx lb lb l l l. Interface Attribute Value T{ .na .nh .BR iswdigit () T} Thread safety MT-Safe locale .TE .SH STANDARDS C11, POSIX.1-2008. .SH HISTORY POSIX.1-2001, C99. .SH NOTES The behavior of .BR iswdigit () depends on the .B LC_CTYPE category of the current locale. .SH SEE ALSO .BR isdigit (3), .BR iswctype (3)