1 /*
2 Copyright (c) 1989 The Regents of the University of California.
3 All rights reserved.
4
5 Redistribution and use in source and binary forms, with or without
6 modification, are permitted provided that the following conditions
7 are met:
8 1. Redistributions of source code must retain the above copyright
9 notice, this list of conditions and the following disclaimer.
10 2. Redistributions in binary form must reproduce the above copyright
11 notice, this list of conditions and the following disclaimer in the
12 documentation and/or other materials provided with the distribution.
13 3. Neither the name of the University nor the names of its contributors
14 may be used to endorse or promote products derived from this software
15 without specific prior written permission.
16
17 THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 SUCH DAMAGE.
28 */
29 /*
30 FUNCTION
31 <<isalpha>>, <<isalpha_l>>---alphabetic character predicate
32
33 INDEX
34 isalpha
35
36 INDEX
37 isalpha_l
38
39 SYNOPSIS
40 #include <ctype.h>
41 int isalpha(int <[c]>);
42
43 #include <ctype.h>
44 int isalpha_l(int <[c]>, locale_t <[locale]>);
45
46 DESCRIPTION
47 <<isalpha>> is a macro which classifies singlebyte charset values by table
48 lookup. It is a predicate returning non-zero when <[c]> represents an
49 alphabetic ASCII character, and 0 otherwise. It is defined only if
50 <[c]> is representable as an unsigned char or if <[c]> is EOF.
51
52 <<isalpha_l>> is like <<isalpha>> but performs the check based on the
53 locale specified by the locale object locale. If <[locale]> is
54 LC_GLOBAL_LOCALE or not a valid locale object, the behaviour is undefined.
55
56 You can use a compiled subroutine instead of the macro definition by
57 undefining the macro using `<<#undef isalpha>>' or `<<#undef isalpha_l>>'.
58
59 RETURNS
60 <<isalpha>>, <<isalpha_l>> return non-zero if <[c]> is a letter.
61
62 PORTABILITY
63 <<isalpha>> is ANSI C.
64 <<isalpha_l>> is POSIX-1.2008.
65
66 No supporting OS subroutines are required.
67 */
68
69 #include <_ansi.h>
70 #include <ctype.h>
71
72 #undef isalpha
73 int
isalpha(int c)74 isalpha (int c)
75 {
76 return(__CTYPE_PTR[c+1] & (_U|_L));
77 }
78
