c++ - C sockets: Echo server bad reply -

i've read many questions i've found, still have problem....

i have sample client/server socket:

• connection stablished between server , client done
• receive message client done
• print message in server side done
• send message server client problems
• print server reply in client side problems

i send message client server without problems, when send message i'm allways getting weird characters

note: i'm adding '\0' character received string

client code

//... socket initialization , other code write(sockfd, msg, strlen(msg));     printf("message sent ! \n");   // listen reply listen(sockfd, 5); struct_size = sizeof(con_addr); serverfd = accept(sockfd, (struct sockaddr*)&con_addr, &struct_size);  // read message bytes_read = read(serverfd, server_reply, 100); server_reply[bytes_read] = '\0'; printf("server response: %s \n", server_reply);  // close socket close(sockfd); close(serverfd); printf("socket closed ! \n");      

server code

//... socket initialization, bind , other code struct_size = sizeof(con_addr); if( (clientfd = accept(sockfd, (struct sockaddr*)&con_addr, &struct_size)) < 0 ){     perror("could not accept connection. error: ");     return 1; }  // read message bytes_read = read(clientfd, client_message, 100); client_message[bytes_read] = '\0';  printf("message received: %s \n", client_message);       // send message n = write(clientfd, client_message , strlen(client_message));     

i'm getting things this:

server response: �v��i�8�y� server response: ��ƿi�8�{�  

you confused on how tcp sockets work:

• servers call socket(2), bind(2), listen(2), accept(2) setup listening socket.
• clients call socket(2) , connect(2) connect server.
• once server returns accept(2) have bi-directional byte pipe between client , server.

it looks attempting connect/accept on both sides.

other notes:

• always check return values of system calls - -1 indication of error, inspect errno(3) actual problem (strerror(3) useful here).
• do not assume data ascii, not use strlen(3) on socket input, use return value of read(2).