ISALNUM(3) NEWLIB ISALNUM(3)NAME
3.1 `isalnum'--alphanumeric character predicate
SYNOPSIS
#include <ctype.h>
int isalnum(int C);
DESCRIPTION
`isalnum' is a macro which classifies ASCII integer values by table
lookup. It is a predicate returning non-zero for alphabetic or numeric
ASCII characters, and `0' for other arguments. It is defined for all
integer values.
You can use a compiled subroutine instead of the macro definition by
undefining the macro using ``#undef isalnum''.
RETURNS
`isalnum' returns non-zero if C is a letter (`a'-`z' or `A'-`Z') or a
digit (`0'-`9').
PORTABILITY
`isalnum' is ANSI C.
No OS subroutines are required.
SEE ALSO
isalnum is part of the library. The full documentation for is main‐
tained as a Texinfo manual. If info and are properly installed at your
site, the command
info
will give you access to the complete manual.
NEWLIB April 2010 ISALNUM(3)