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.\" 3. 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.\" @(#)isxdigit.3 8.1 (Berkeley) 6/4/93 33.\" 34.Dd December 19, 2022 35.Dt ISXDIGIT 3 36.Os 37.Sh NAME 38.Nm isxdigit , 39.Nm ishexnumber , 40.Nm isxdigit_l , 41.Nm ishexnumber_l 42.Nd hexadecimal-digit character test 43.Sh LIBRARY 44.Lb libc 45.Sh SYNOPSIS 46.In ctype.h 47.Ft int 48.Fn isxdigit "int c" 49.Ft int 50.Fn ishexnumber "int c" 51.Ft int 52.Fn isxdigit_l "int c" "locale_t loc" 53.Ft int 54.Fn ishexnumber_l "int c" "locale_t loc" 55.Sh DESCRIPTION 56The 57.Fn isxdigit 58and 59.Fn isxdigit_l 60functions test for any hexadecimal-digit character. 61Regardless of locale, this includes the following characters only: 62.Bl -column \&``0''______ \&``0''______ \&``0''______ \&``0''______ \&``0''______ 63.It "\&``0''" Ta "``1''" Ta "``2''" Ta "``3''" Ta "``4''" 64.It "\&``5''" Ta "``6''" Ta "``7''" Ta "``8''" Ta "``9''" 65.It "\&``A''" Ta "``B''" Ta "``C''" Ta "``D''" Ta "``E''" 66.It "\&``F''" Ta "``a''" Ta "``b''" Ta "``c''" Ta "``d''" 67.It "\&``e''" Ta "``f''" Ta \& Ta \& Ta \& 68.El 69.Pp 70The 71.Fn ishexnumber 72and 73.Fn ishexnumber_l 74functions behave similarly to 75.Fn isxdigit 76and 77.Fn isxdigit_l , 78but may recognize additional characters, 79depending on the current locale setting. 80.Pp 81The value of the argument must be representable as an 82.Vt "unsigned char" 83or the value of 84.Dv EOF . 85.Pp 86The _l-suffixed versions take an explicit locale argument, whereas the 87non-suffixed versions use the current global or per-thread locale. 88.Sh RETURN VALUES 89The 90.Fn isxdigit 91and 92.Fn isxdigit_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 iswxdigit 104or 105.Fn iswxdigit_l 106function should be used instead. 107.Sh SEE ALSO 108.Xr ctype 3 , 109.Xr ctype_l 3 , 110.Xr iswxdigit 3 , 111.Xr iswxdigit_l 3 , 112.Xr xlocale 3 , 113.Xr ascii 7 114.Sh STANDARDS 115The 116.Fn isxdigit 117function conforms to 118.St -isoC . 119.Sh HISTORY 120The 121.Fn ishexnumber 122function appeared in 123.Bx 4.4 . 124