10.2.5.1 Examples of Login Verification Functions

As an example, let’s consider the function for analyzing a line of output from a standard UNIX finger service. In each line of finger output, the first field contains the user name; the third field, the tty number (port ID); and the seventh field, the session ID. The function must return 1 if the three fields match the input user name, as well as its port and session IDs:

integer
check_unix(string str, string name, integer pid, string sid)
{
    return field(str, 1) == name
           && field(str, 3) == pid
           && field(str, 7) == sid;
}

The next example is a function to analyze a line of output from an SNMP query returning a user name. This function must return 1 if the entire input line matches the user name:

integer
check_username(string str, string name, integer pid, string sid)
{
    return str == name;
}