/* CLIENT PROGRAM 1.6 */ #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <errno.h> #include <string.h> #include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> #include <netdb.h> #define MYPORT 2317 int main(int argc,char *argv[]) { int sockfd; struct sockaddr_in their_addr; struct hostent *he; int numbytes; if (argc < 3) { fprintf(stderr, "Client-Usage: %s <hostname> <message>n", argv[0]); exit(1); } if ((he = gethostbyname(argv[1])) == NULL) { perror("Client-gethostbyname() error lol!"); exit(1); } else printf("Client-gethostname() is OK...n"); if((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) { perror("Client-socket() error lol!"); exit(1); } else printf("Client-socket() sockfd is OK...n"); their_addr.sin_family = AF_INET; their_addr.sin_port = htons(MYPORT); their_addr.sin_addr = *((struct in_addr *)he->h_addr); memset(&(their_addr.sin_zero), '', 8); if((connect(sockfd,(struct sockaddr *)&their_addr,sizeof(their_addr))) < 0) { perror("Client-connect is error"); exit(1); } else printf("Client-connect is ok.."); if((numbytes = send(sockfd, argv[2], strlen(argv[2]), 0)) == -1) { perror("Client-sendto() error lol!"); exit(1); } else printf("Client-sendto() is OK...n"); printf("sent %d bytes to %sn", numbytes, inet_ntoa(their_addr.sin_addr)); if (close(sockfd) != 0) printf("Client-sockfd closing is failed!n"); else printf("Client-sockfd successfully closed!n"); return 0; } /********sever programing ************/ #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <errno.h> #include <string.h> #include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> #define MYPORT 2317 #define MAXBUFLEN 500 int main(int argc, char *argv[]) { char buf[MAXBUFLEN]; int sockfd,newsockfd; struct sockaddr_in my_addr; struct sockaddr_in their_addr; int addr_len, numbytes; memset(buf,0x00,sizeof(buf)); if((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) { perror("Server-socket() sockfd error lol!"); exit(1); } else printf("Server-socket() sockfd is OK...n"); my_addr.sin_family = AF_INET; my_addr.sin_port = htons(MYPORT); my_addr.sin_addr.s_addr = INADDR_ANY; memset(&(my_addr.sin_zero), '',if(bind(sockfd, (struct sockaddr *)&my_addr, sizeof(struct sockaddr)) == -1) { perror("Server-bind() error lol!"); exit(1); } else printf("Server-bind() is OK...n"); if((listen(sockfd,10))== -1) { perror("Socket-listen error"); exit(1); } else printf("Socket-listen is ok.."); addr_len=sizeof(struct sockaddr); if(( newsockfd=accept(sockfd,(struct sockaddr*)&their_addr, &addr_len)) == -1) { perror("Server-accept is error"); exit(1); } else printf("Server-accept is ok..n"); 8); addr_len = sizeof(struct sockaddr); if(numbytes = recv(sockfd, buf, strlen(buf), 0) == -1) { perror("Server-recvfrom() error lol!"); exit(1); } else { printf("Server-Waiting and listening...n"); printf("Server-recvfrom() is OK...n%sn",buf); } printf("Server-Got packet from :%sn", inet_ntoa(their_addr.sin_addr)); printf("Server-Packet is %d bytes longn", numbytes); if(close(sockfd) != 0) printf("Server-sockfd closing failed!n"); else printf("Server-sockfd successfully closed!n"); return 0; } /****i got this error**/ Client-gethostname() is OK... Client-socket() sockfd is OK... Client-connect is error: Connection refused

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