multiple nak strings

[labnotes]

Good Day!!

I am creating a program to send and receive input from a telnet session in C/C++.
I create the pipes, can send and receive and look for an "ack" string and "nak" string ok.
Now I want to look for multiple naks strings coming in from the input pipe. Any suggestions ??
Here is my function to send and receive one
ack and one nak string. I want to expand the nak to more that one nak string.

int SendReceive(const char *cmd, const char *ack, const char *nak, int timeout, int printonly)
{
        int ai, ni, r;
        char c;
        char cmd1[MAXINPUT];

        r = 0;

        if (cmd && strlen(cmd))
        {
                if (printonly)
                {
                        if (cmd[0] == '\020')
                                cout << "^P" << cmd + 1; // NB: true ^P turns on printing on DOS
                        else cout << cmd;
                        return -1;

                }cout << cmd << endl; //Uncomment this line to see traffic
                write(fdwr, cmd, strlen(cmd)); // June 07,2004
        }

        if (ack != NULL)
        {
                alarm(timeout);
                alarmed = 0;
                ai = 0;
                ni = 0;
                while (!alarmed)
                {
                        if (read(fdrd, &c, 1) < 0)
                        {
                                if (errno == EINTR) continue;
                                if (errno == EAGAIN) continue;
                                break;
                        }
                        if (ack[ai] == c) ai++;
                        else ai = 0;
                        if (ack[ai] == '\0')
                        {
                                r = -1;
                                break;
                        }
                        if (nak)
                        {
                                if (nak[ni] == c) ni++;
                                else ni = 0;
                                if (nak[ni] == '\0'){cout << "break2" << endl; break;}
                        }
                }
                if (alarmed)

                        syslog(LOG_INFO, "Timeout while waiting for command response.");

                else if (nak && nak[ni] == '\0')
                        syslog(LOG_INFO, "Negative command response.");

                else if (!r)
                        syslog(LOG_INFO, "Unspecified error while waiting for command response.");


              unalarm();
        }

        else r = -1;

        return r;

}

Thanks and have a great day