Returned Value Status

The following sections describe the return value status of functions with natural return values and functions with no natural return value.

Functions with Natural Return Values

If a ToolTalk function has a natural return value such as a pointer or an integer, a special error value is returned instead of the real value.

Functions with No Natural Return Values

If a ToolTalk function does not have a natural return value, the return value is an element of Tt_status enum.

To see if there is an error, use the ToolTalk macro tt_is_err, which returns an integer.

• If the return value is 0, the Tt_status enum is either TT_OK or a warning.

• If the return value is 1, the Tt_status enum is an error.

If there is an error, you can use the tt_status_message function to obtain the character string that explains the Tt_status code, as shown in .

Example 14-1 Obtaining an Error Explanation

char *spec_id, my_application_name;
Tt_status tterr;

tterr = tt_spec_write(spec_id);
if (tt_is_err(tterr)) {
    fprintf(stderr, “%s: %s\n”, my_application_name,
        tt_status_message(tterr));
}