1.\" $OpenBSD: isalnum.3,v 1.12 2017/09/05 03:16:13 schwarze Exp $ 2.\" 3.\" Copyright (c) 1991 The Regents of the University of California. 4.\" Copyright (c) 2017 Ingo Schwarze <schwarze@openbsd.org> 5.\" All rights reserved. 6.\" 7.\" This code is derived from software contributed to Berkeley by 8.\" the American National Standards Committee X3, on Information 9.\" Processing Systems. 10.\" 11.\" Redistribution and use in source and binary forms, with or without 12.\" modification, are permitted provided that the following conditions 13.\" are met: 14.\" 1. Redistributions of source code must retain the above copyright 15.\" notice, this list of conditions and the following disclaimer. 16.\" 2. Redistributions in binary form must reproduce the above copyright 17.\" notice, this list of conditions and the following disclaimer in the 18.\" documentation and/or other materials provided with the distribution. 19.\" 3. Neither the name of the University nor the names of its contributors 20.\" may be used to endorse or promote products derived from this software 21.\" without specific prior written permission. 22.\" 23.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33.\" SUCH DAMAGE. 34.\" 35.Dd $Mdocdate: September 5 2017 $ 36.Dt ISALNUM 3 37.Os 38.Sh NAME 39.Nm isalnum , 40.Nm isalnum_l 41.Nd alphanumeric single-byte character test 42.Sh SYNOPSIS 43.In ctype.h 44.Ft int 45.Fn isalnum "int c" 46.Ft int 47.Fn isalnum_l "int c" "locale_t locale" 48.Sh DESCRIPTION 49The 50.Fn isalnum 51function tests for any character for which 52.Xr isalpha 3 53or 54.Xr isdigit 3 55is true, and 56.Fn isalnum_l 57tests for any character for which 58.Xr isalpha_l 3 59or 60.Xr isdigit_l 3 61is true. 62.Pp 63In the C locale, the complete list of alphanumeric characters 64is A\(enZ, a\(enz, 0, and 1\(en9. 65.Ox 66always uses the C locale for these functions, 67ignoring the global locale, the thread-specific locale, and the 68.Fa locale 69argument. 70.Sh RETURN VALUES 71These functions return zero if the character tests false or 72non-zero if the character tests true. 73.Sh ENVIRONMENT 74On systems supporting non-ASCII single-byte character encodings, 75these functions may return non-zero for additional characters, 76and the results of 77.Fn isalnum 78may depend on the 79.Ev LC_CTYPE 80.Xr locale 1 . 81.Sh SEE ALSO 82.Xr isalpha 3 , 83.Xr isascii 3 , 84.Xr isblank 3 , 85.Xr iscntrl 3 , 86.Xr isdigit 3 , 87.Xr isgraph 3 , 88.Xr islower 3 , 89.Xr isprint 3 , 90.Xr ispunct 3 , 91.Xr isspace 3 , 92.Xr isupper 3 , 93.Xr iswalnum 3 , 94.Xr isxdigit 3 , 95.Xr stdio 3 , 96.Xr toascii 3 , 97.Xr tolower 3 , 98.Xr toupper 3 , 99.Xr ascii 7 100.Sh STANDARDS 101The 102.Fn isalnum 103function conforms to 104.St -ansiC , 105and 106.Fn isalnum_l 107to 108.St -p1003.1-2008 . 109.Sh HISTORY 110The 111.Fn isalnum 112function first appeared in 113.At v7 , 114and 115.Fn isalnum_l 116has been available since 117.Ox 6.2 . 118.Sh CAVEATS 119The argument 120.Fa c 121must be 122.Dv EOF 123or representable as an 124.Li unsigned char ; 125otherwise, the result is undefined. 126