isalpha -- alphabetic character test
Standard C Library (libc, -lc)
#include <ctype.h>
int
isalpha(int c);
The isalpha() function tests for any character for which isupper(3) or
islower(3) is true. For single C chars locales (see multibyte(3)) the
value of the argument is representable as an unsigned char or the value
of EOF. In the ASCII character set, this includes the following characters
(with their numeric values shown in octal):
101 ``A'' 102 ``B'' 103 ``C'' 104 ``D'' 105 ``E''
106 ``F'' 107 ``G'' 110 ``H'' 111 ``I'' 112 ``J''
113 ``K'' 114 ``L'' 115 ``M'' 116 ``N'' 117 ``O''
120 ``P'' 121 ``Q'' 122 ``R'' 123 ``S'' 124 ``T''
125 ``U'' 126 ``V'' 127 ``W'' 130 ``X'' 131 ``Y''
132 ``Z'' 141 ``a'' 142 ``b'' 143 ``c'' 144 ``d''
145 ``e'' 146 ``f'' 147 ``g'' 150 ``h'' 151 ``i''
152 ``j'' 153 ``k'' 154 ``l'' 155 ``m'' 156 ``n''
157 ``o'' 160 ``p'' 161 ``q'' 162 ``r'' 163 ``s''
164 ``t'' 165 ``u'' 166 ``v'' 167 ``w'' 170 ``x''
171 ``y'' 172 ``z''
The isalpha() function returns zero if the character tests false and
returns non-zero if the character tests true.
Although isalpha() accepts arguments outside of the range of the unsigned
char type in locales with large character sets, this is a 4.4BSD extension
and the iswalpha() function should be used instead for maximum
portability.
ctype(3), islower(3), isupper(3), iswalpha(3), multibyte(3), ascii(7)
The isalpha() function conforms to ISO/IEC 9899:1990 (``ISO C89'').
FreeBSD 5.2.1 October 6, 2002 FreeBSD 5.2.1 [ Back ] |