MirBSD manpage: isdigit(3)

ISDIGIT(3)                 BSD 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.

RETURN VALUES

     The isdigit() macro returns zero if the character tests false or non-zero
     if the character tests true.

SEE ALSO

     isalnum(3), isalpha(3), isascii(3), isblank(3), iscntrl(3), isgraph(3),
     islower(3), isprint(3), ispunct(3), isspace(3), isupper(3), isxdigit(3),
     stdio(3), toascii(3), tolower(3), toupper(3), ascii(7)

STANDARDS

     The isdigit() function conforms to ANSI X3.159-1989 ("ANSI C89").

CAVEATS

     The argument to isdigit() must be EOF or representable as an unsigned
     char; otherwise, the result is undefined.

MirBSD #10-current              June 29, 1991                                1