tail head cat sleep
QR code linking to this page

Manual Pages  — ISALNUM

NAME

isalnum – alphanumeric character test

CONTENTS

LIBRARY

Standard C Library (libc, -lc)

SYNOPSIS

#include <ctype.h>

int
isalnum(int c);

int
isalnum_l(int c, locale_t loc);

DESCRIPTION

The isalnum() function tests for any character for which isalpha(3) or isdigit(3) is true. The value of the argument must be 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):

060 ``0''
061 ``1'' 062 ``2'' 063 ``3'' 064 ``4''

065 ``5''
066 ``6'' 067 ``7'' 070 ``8'' 071 ``9''

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 isalnum_l() function takes an explicit locale argument, whereas the isalnum() function uses the current global or per-thread locale.

RETURN VALUES

The isalnum() function returns zero if the character tests false and returns non-zero if the character tests true.

COMPATIBILITY

The BSD 4.4 extension of accepting arguments outside of the range of the unsigned char type in locales with large character sets is considered obsolete and may not be supported in future releases. The iswalnum() function should be used instead.

SEE ALSO

ctype(3), isalpha(3), isdigit(3), iswalnum(3), xlocale(3), ascii(7)

STANDARDS

The isalnum() function conforms to ISO/IEC 9899:1990 ("ISO C90"). The isalnum_l() function conforms to IEEE Std 1003.1-2008 ("POSIX.1").

ISALNUM (3) July 17, 2005

tail head cat sleep
QR code linking to this page


Please direct any comments about this manual page service to Ben Bullock. Privacy policy.

What will happen when the 32-bit Unix date goes negative in mid-January 2038 does not bear thinking about.
— Henry Spencer