_CP_precision is equivalent to the precision number BASIC statement.
void _CP_precision(int number)
This function affects the precision of the _CP_rs_ and the _CP_sr_ functions.
This example displays "1.12" since the conversion is truncated to the precision of 2.
CPSTR * s = _CP_mkstr("1.12345");
double r;
_CP_precision(2);
r = _CP_sr_(s);
_CP_unix_env();
printf("%g\n", r);
_CP_str_free(s);