HP C/iX Library Reference Manual (30026-90004)

214 Chapter5
HP C/iX Library Function Descriptions
isalnum
isalnum
Tests whether an argument is a letter or a decimal digit.
Syntax
#include <ctype.h>
int isalnum (int c );
Parameters
c An argument to be evaluated. The argument must be representable as an
unsigned char or the macro EOF.
Return Values
≠0 The argument passed in c is a letter or a decimal digit.
0 The argument passed in
c is not a letter or a decimal digit.
Description
The isalnum function returns a nonzero value if the argument passed in c is a letter or a
decimal digit (ASCII characters 0 through 9, A through Z, and a through z); otherwise, zero
is returned.
See Also
isalpha(), iscntrl(), isdigit(), isgraph(), islower(), isprint(), ispunct(),
isspace(), isupper(), isxdigit(), ANSI C 4.3.1.1, POSIX.1 8.1