1.\" Copyright (c) 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" This code is derived from software contributed to Berkeley by 5.\" the American National Standards Committee X3, on Information 6.\" Processing Systems. 7.\" 8.\" Redistribution and use in source and binary forms, with or without 9.\" modification, are permitted provided that the following conditions 10.\" are met: 11.\" 1. Redistributions of source code must retain the above copyright 12.\" notice, this list of conditions and the following disclaimer. 13.\" 2. Redistributions in binary form must reproduce the above copyright 14.\" notice, this list of conditions and the following disclaimer in the 15.\" documentation and/or other materials provided with the distribution. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)isdigit.3 8.1 (Berkeley) 6/4/93 33.\" $FreeBSD: head/lib/libc/locale/isdigit.3 233992 2012-04-07 09:05:30Z joel $ 34.\" 35.Dd December 25, 2013 36.Dt ISDIGIT 3 37.Os 38.Sh NAME 39.Nm isdigit , isdigit_l , isnumber , isnumber_l 40.Nd decimal-digit character test 41.Sh LIBRARY 42.Lb libc 43.Sh SYNOPSIS 44.In ctype.h 45.Ft int 46.Fn isdigit "int c" 47.Ft int 48.Fn isnumber "int c" 49.Ft int 50.Fn isdigit_l "int c" "locale_t locale" 51.In xlocale.h 52.Ft int 53.Fn isnumber_l "int c" "locale_t locale" 54.Sh DESCRIPTION 55The 56.Fn isdigit 57and 58.Fn isdigit_l 59functions test for a decimal digit character. 60Regardless of locale, this includes the following characters only: 61.Bl -column \&``0''______ \&``0''______ \&``0''______ \&``0''______ \&``0''______ 62.It "\&``0''" Ta "``1''" Ta "``2''" Ta "``3''" Ta "``4''" 63.It "\&``5''" Ta "``6''" Ta "``7''" Ta "``8''" Ta "``9''" 64.El 65.Pp 66The 67.Fn isnumber 68and 69.Fn isnumber_l 70functions behave similarly to 71.Fn isdigit 72and 73.Fn isdigit_l , 74but may recognize additional characters, depending on the current locale 75setting. 76.Pp 77The value of the argument must be representable as an 78.Vt "unsigned char" 79or the value of 80.Dv EOF . 81.Pp 82The _l-suffixed versions take an explicit 83.Fa locale 84argument, whereas the 85non-suffixed versions use the current global or per-thread locale. 86.Sh RETURN VALUES 87The 88.Fn isdigit , 89.Fn isdigit_l , 90.Fn isnumber , 91and 92.Fn isnumber_l 93functions return zero if the character tests false and 94return non-zero if the character tests true. 95.Sh COMPATIBILITY 96The 97.Bx 4.4 98extension of accepting arguments outside of the range of the 99.Vt "unsigned char" 100type in locales with large character sets is considered obsolete 101and may not be supported in future releases. 102The 103.Fn iswdigit , 104.Fn iswdigit_l , 105.Fn iswnumber , 106and 107.Fn iswnumber_l 108functions should be used instead. 109.Sh SEE ALSO 110.Xr ctype 3 , 111.Xr ctype_l 3 , 112.Xr iswdigit 3 , 113.Xr iswdigit_l 3 , 114.Xr multibyte 3 , 115.Xr xlocale 3 , 116.Xr ascii 7 117.Sh STANDARDS 118The 119.Fn isdigit 120function conforms to 121.St -isoC . 122The 123.Fn isdigit_l 124function conforms to 125.St -p1003.1-2008 . 126.Sh HISTORY 127The 128.Fn isnumber 129function appeared in 130.Bx 4.4 . 131