1.\"	$NetBSD: isalpha.3,v 1.14 2008/04/17 16:25:36 apb Exp $
2.\"
3.\" Copyright (c) 1991 The Regents of the University of California.
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6.\" This code is derived from software contributed to Berkeley by
7.\" the American National Standards Committee X3, on Information
8.\" Processing Systems.
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34.\"     @(#)isalpha.3	5.2 (Berkeley) 6/29/91
35.\"
36.Dd April 17, 2008
37.Dt ISALPHA 3
38.Os
39.Sh NAME
40.Nm isalpha
41.Nd alphabetic character test
42.Sh LIBRARY
43.Lb libc
44.Sh SYNOPSIS
45.In ctype.h
46.Ft int
47.Fn isalpha "int c"
48.Sh DESCRIPTION
49The
50.Fn isalpha
51function tests for any character for which
52.Xr isupper 3
53or
54.Xr islower 3
55is true and
56.\" , or any of an implementation-defined set of characters
57for which none of
58.Xr iscntrl 3 ,
59.Xr isdigit 3 ,
60.Xr ispunct 3 ,
61or
62.Xr isspace 3
63is true.
64In the
65.Em ``C''
66locale,
67.Fn isalpha
68returns true only for the characters for which
69.Xr isupper 3
70or
71.Xr islower 3
72is true.
73.Sh RETURN VALUES
74The
75.Fn isalpha
76function returns zero if the character tests false and
77returns non-zero if the character tests true.
78.Sh SEE ALSO
79.Xr ctype 3 ,
80.Xr isalnum 3 ,
81.Xr isascii 3 ,
82.Xr isblank 3 ,
83.Xr iscntrl 3 ,
84.Xr isdigit 3 ,
85.Xr isgraph 3 ,
86.Xr islower 3 ,
87.Xr isprint 3 ,
88.Xr ispunct 3 ,
89.Xr isspace 3 ,
90.Xr isupper 3 ,
91.Xr isxdigit 3 ,
92.Xr stdio 3 ,
93.Xr toascii 3 ,
94.Xr tolower 3 ,
95.Xr toupper 3 ,
96.Xr ascii 7
97.Sh STANDARDS
98The
99.Fn isalpha
100function conforms to
101.St -ansiC .
102.Sh CAVEATS
103The argument to
104.Fn isalpha
105must be
106.Dv EOF
107or representable as an
108.Vt unsigned char ;
109otherwise, the behavior is undefined.
110See the
111.Sx CAVEATS
112section of
113.Xr ctype 3
114for more details.
115