undefined functions in g++

/**************************************************************************
*       this is an object oriented client                                 *

**************************************************************************/
#include <stdarg.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <sys/socket.h>
#include <resolv.h>

#define MAXBUF  1024
#define PORT    9999

struct message{
        int     ident;
        char    data[MAXBUF];};

class cOneThrdClient{
        private:
                int             sockfd;
                int             bytes_read;
                struct          sockaddr_in dest;
                message         block;
                char            serv[40];
        public:
                cOneThrdClient(char *mess, char *server);
                bool connekt();
                bool sndMsg();
                bool recvMsg();
};

cOneThrdClient::cOneThrdClient(char *mess, char *server){
        strcpy(block.data,mess); bytes_read = 0; block.ident = 69;
        if( (sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0){
                perror("Socket");}

        /*---Initialize server address/port struct---*/
        bzero(&dest, sizeof(dest));
        dest.sin_family = AF_INET;
        if ( inet_addr(server, &dest.sin_addr.s_addr) == 0 ){  <-- error in this function call
                perror(serv);}

        dest.sin_port = htons(PORT);
}

bool cOneThrdClient::connekt(){
        if ( connect(sockfd, (struct sockaddr *)&dest, sizeof(dest)) != 0 ){
                perror("Connect");}
}

bool cOneThrdClient::sndMsg(){
        send(sockfd, &block, sizeof(block), 0);
}

bool cOneThrdClient::recvMsg(){
        /*---While there's data, read and print it---*/
        do{
                bzero(&block, sizeof(block));
                bytes_read = recv(sockfd, &block, sizeof(block), 0);
                if ( bytes_read > 0 )
                        printf("%s\n", block.data);}
        while ( bytes_read > 0 );

        /*---Clean up---*/
        close(sockfd);   <-- error in this function call
}

int main(int Count, char *Strings[])
{
        cOneThrdClient *cPtr = new cOneThrdClient(Strings[1], Strings[2]);

        cPtr->connekt(); cPtr->sndMsg(); cPtr->recvMsg();

        return 1;
}