server.c
1 #include <stdio.h> 2 #include <stdlib.h> 3 #include <string.h> 4 #include <unistd.h> 5 #include <arpa/inet.h> 6 #include <sys/socket.h> 7 8 void error_handing(char *message); 9 10 int main(int argc, char *argv[]) 11 { 12 int serv_sock; 13 int clnt_sock; 14 15 struct sockaddr_in serv_addr; 16 struct sockaddr_in clnt_addr; 17 socklen_t clnt_addr_size; 18 19 char message[] = "Hello World!"; 20 21 if(argc != 2) 22 { 23 printf("Usage : %s <port> ", argv[0]); 24 exit(1); 25 } 26 27 serv_sock = socket(PF_INET, SOCK_STREAM, 0); 28 if(serv_sock == -1) 29 error_handing("socket() error"); 30 31 memset(&serv_addr, 0, sizeof(serv_addr)); 32 serv_addr.sin_family = AF_INET; 33 serv_addr.sin_addr.s_addr = htonl(INADDR_ANY); 34 serv_addr.sin_port = htons(atoi(argv[1])); 35 36 if(bind(serv_sock, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) == -1) 37 error_handing("bind() error"); 38 39 if(listen(serv_sock, 5) == -1) 40 error_handing("listen() error"); 41 42 clnt_addr_size = sizeof(clnt_addr); 43 clnt_sock = accept(serv_sock, (struct sockaddr *)&clnt_addr, &clnt_addr_size); 44 if(clnt_sock == -1) 45 error_handing("accept() error"); 46 47 write(clnt_sock, message, sizeof(message)); 48 close(clnt_sock); 49 close(serv_sock); 50 return 0; 51 } 52 53 void error_handing(char *message) 54 { 55 fputs(message, stderr); 56 fputc(' ', stderr); 57 exit(1); 58 }
client.c
1 #include <stdio.h> 2 #include <stdlib.h> 3 #include <string.h> 4 #include <unistd.h> 5 #include <arpa/inet.h> 6 #include <sys/socket.h> 7 void error_handing(char *message); 8 9 int main(int argc, char *argv[]) 10 { 11 int sock; 12 struct sockaddr_in serv_addr; 13 char message[30]; 14 int str_len; 15 16 if(argc != 3) 17 { 18 printf("Usage : %s <IP> <port> ", argv[0]); 19 exit(1); 20 } 21 22 sock = socket(PF_INET, SOCK_STREAM, 0); 23 if(sock ==-1) 24 error_handing("socket() error"); 25 26 memset(&serv_addr, 0, sizeof(serv_addr)); 27 serv_addr.sin_family = AF_INET; 28 serv_addr.sin_addr.s_addr = inet_addr(argv[1]); 29 serv_addr.sin_port = htons(atoi(argv[2])); 30 31 if(connect(sock, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) == -1) 32 error_handing("connect() error"); 33 34 str_len = read(sock, message, sizeof(message) - 1); 35 if(str_len == -1) 36 error_handing("read() error"); 37 printf("Message from server : %s ", message); 38 close(sock); 39 return 0; 40 } 41 42 void error_handing(char *message) 43 { 44 fputs(message, stderr); 45 fputc(' ', stderr); 46 exit(1); 47 }