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.\" @(#)isalpha.3 8.1 (Berkeley) 6/4/93 33.\" $FreeBSD$ 34.\" 35.Dd July 17, 2005 36.Dt ISALPHA 3 37.Os 38.Sh NAME 39.Nm isalpha 40.Nd alphabetic character test 41.Sh LIBRARY 42.Lb libc 43.Sh SYNOPSIS 44.In ctype.h 45.Ft int 46.Fn isalpha "int c" 47.Sh DESCRIPTION 48The 49.Fn isalpha 50function tests for any character for which 51.Xr isupper 3 52or 53.Xr islower 3 54is true. 55The value of the argument must be representable as an 56.Vt "unsigned char" 57or the value of 58.Dv EOF . 59.Pp 60In the ASCII character set, this includes the following characters 61(with their numeric values shown in octal): 62.Pp 63.Bl -column \&000_``0''__ \&000_``0''__ \&000_``0''__ \&000_``0''__ \&000_``0''__ 64.It "\&101\ ``A'' \t102\ ``B'' \t103\ ``C'' \t104\ ``D'' \t105\ ``E''" 65.It "\&106\ ``F'' \t107\ ``G'' \t110\ ``H'' \t111\ ``I'' \t112\ ``J''" 66.It "\&113\ ``K'' \t114\ ``L'' \t115\ ``M'' \t116\ ``N'' \t117\ ``O''" 67.It "\&120\ ``P'' \t121\ ``Q'' \t122\ ``R'' \t123\ ``S'' \t124\ ``T''" 68.It "\&125\ ``U'' \t126\ ``V'' \t127\ ``W'' \t130\ ``X'' \t131\ ``Y''" 69.It "\&132\ ``Z'' \t141\ ``a'' \t142\ ``b'' \t143\ ``c'' \t144\ ``d''" 70.It "\&145\ ``e'' \t146\ ``f'' \t147\ ``g'' \t150\ ``h'' \t151\ ``i''" 71.It "\&152\ ``j'' \t153\ ``k'' \t154\ ``l'' \t155\ ``m'' \t156\ ``n''" 72.It "\&157\ ``o'' \t160\ ``p'' \t161\ ``q'' \t162\ ``r'' \t163\ ``s''" 73.It "\&164\ ``t'' \t165\ ``u'' \t166\ ``v'' \t167\ ``w'' \t170\ ``x''" 74.It "\&171\ ``y'' \t172\ ``z''" 75.El 76.Sh RETURN VALUES 77The 78.Fn isalpha 79function returns zero if the character tests false and 80returns non-zero if the character tests true. 81.Sh COMPATIBILITY 82The 83.Bx 4.4 84extension of accepting arguments outside of the range of the 85.Vt "unsigned char" 86type in locales with large character sets is considered obsolete 87and may not be supported in future releases. 88The 89.Fn iswalpha 90function should be used instead. 91.Sh SEE ALSO 92.Xr ctype 3 , 93.Xr islower 3 , 94.Xr isupper 3 , 95.Xr iswalpha 3 , 96.Xr ascii 7 97.Sh STANDARDS 98The 99.Fn isalpha 100function conforms to 101.St -isoC . 102