ISDIGIT(3) MachTen Programmer’s Manual ISDIGIT(3)

NAME
isdigit - decimal-digit character test

SYNOPSIS
#include <ctype.h>

int
isdigit(int c);

DESCRIPTION
The isdigit() function tests for any decimal-digit character. In the
ASCII character set, this includes the following characters:

060 ‘‘0’’ 061 ‘‘1’’ 062 ‘‘2’’ 063 ‘‘3’’ 064 ‘‘4’’
065 ‘‘5’’ 066 ‘‘6’’ 067 ‘‘7’’ 070 ‘‘8’’ 071 ‘‘9’’

RETURN VALUES
The isdigit() function returns zero if the character tests false and re-
turns non-zero if the character tests true.

SEE ALSO
ctype(3), ascii(7)

STANDARDS
The isdigit() function conforms to ANSI C3.159-1989 (‘‘ANSI C’’).

4.4BSD June 4, 1993 1