1.\" Copyright (c) 1991 The Regents of the University of California. 2.\" 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. All advertising materials mentioning features or use of this software 17.\" must display the following acknowledgement: 18.\" This product includes software developed by the University of 19.\" California, Berkeley and its contributors. 20.\" 4. Neither the name of the University nor the names of its contributors 21.\" may be used to endorse or promote products derived from this software 22.\" without specific prior written permission. 23.\" 24.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34.\" SUCH DAMAGE. 35.\" 36.\" from: @(#)isalpha.3 5.2 (Berkeley) 6/29/91 37.\" $Id: isalpha.3,v 1.2 1993/07/30 08:37:05 mycroft Exp $ 38.\" 39.Dd June 29, 1991 40.Dt ISALPHA 3 41.Os 42.Sh NAME 43.Nm isalpha 44.Nd alphabetic character test 45.Sh SYNOPSIS 46.Fd #include <ctype.h> 47.Ft int 48.Fn isalpha "int c" 49.Sh DESCRIPTION 50The 51.Fn isalpha 52function tests for any character for which 53.Xr isupper 3 54or 55.Xr islower 3 56is true and 57.\" , or any of an implementation-defined set of characters 58for which none of 59.Xr iscntrl 3 , 60.Xr isdigit 3 , 61.Xr ispunct 3 , 62or 63.Xr isspace 3 64is true. 65In the 66.Em ``C'' 67locale, 68.Fn isalpha 69returns true only for the characters for which 70.Xr isupper 3 71or 72.Xr islower 3 73is true. 74.Sh RETURN VALUES 75The 76.Fn isalpha 77macro returns zero if the character tests false and 78returns non-zero if the character tests true. 79.Sh SEE ALSO 80.Xr isascii 3 , 81.Xr isalnum 3 , 82.Xr iscntrl 3 , 83.Xr isdigit 3 , 84.Xr isgraph 3 , 85.Xr islower 3 , 86.Xr isprint 3 , 87.Xr ispunct 3 , 88.Xr isspace 3 , 89.Xr isupper 3 , 90.Xr isxdigit 3 , 91.Xr toascii 3 , 92.Xr tolower 3 , 93.Xr toupper 3 , 94.Xr stdio 3 95.Xr ascii 7 96.Sh STANDARDS 97The 98.Fn isalpha 99function conforms to 100.St -ansiC . 101