HP 3000 Manuals

HP C/iX Library Reference Manual

isdigit 

Tests whether an argument is a decimal digit.

Syntax 

     #include <ctype.h>
     int isdigit (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 decimal digit.

0             The argument passed in c is not a decimal digit.

Description 

The isdigit function returns a nonzero value if the argument passed in c 
is a decimal digit (ASCII characters 0 through 9); otherwise, the
returned value is zero.

See Also 

isalnum(), isalpha(), iscntrl(), isgraph(), islower(), isprint(),
ispunct(), isspace(), isupper(), isxdigit(), ANSI C 4.3.1.4, POSIX.1 8.1

MPE/iX 5.0 Documentation