ISDIGIT(3) NEWLIB ISDIGIT(3)NAME
3.5 `isdigit'--decimal digit predicate
SYNOPSIS
#include <ctype.h>
int isdigit(int C);
DESCRIPTION
`isdigit' is a macro which classifies ASCII integer values by table
lookup. It is a predicate returning non-zero for decimal digits, and 0
for other characters. It is defined only when `isascii'(C) is true or
C is EOF.
You can use a compiled subroutine instead of the macro definition by
undefining the macro using ``#undef isdigit''.
RETURNS
`isdigit' returns non-zero if C is a decimal digit (`0'-`9').
PORTABILITY
`isdigit' is ANSI C.
No supporting OS subroutines are required.
SEE ALSOisdigit 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 ISDIGIT(3)
