1. #include <stdio.h>
2. #include <stdlib.h>
3. #include <sys/types.h>
4. #include <sys/socket.h>
5. #include <netinet/in.h>
6. #include <unistd.h>
7. #include <string.h>
8.  
9. #define SIZE 1000
10.  
11. int main() {
12.     char serverMessage[SIZE] = "You have a missed call from server\n";
13.  
14.     int socketDescriptor = socket(AF_INET, SOCK_STREAM, 0);
15.  
16.     struct sockaddr_in serverAddress;
17.     serverAddress.sin_family = AF_INET;
18.     serverAddress.sin_port = htons(9002);
19.     serverAddress.sin_addr.s_addr = INADDR_ANY;
20.  
21.     bind(socketDescriptor, (struct sockaddr*) &serverAddress;, sizeof(serverAddress));
22.  
23.     listen(socketDescriptor, 5);
24.  
25.     int client_socket = accept(socketDescriptor, NULL, NULL);
26.  
27.     pid_t pid = fork();
28.  
29.     if (pid < 0) {
30.         fprintf(stderr, "Fork failed\n");
31.         return 1;
32.     }
33.  
34.     if (pid == 0) {
35.         // Child process (server receive message from client)
36.         char clientMessage[SIZE];
37.         while (1) {
38.             recv(client_socket, &clientMessage;, sizeof(clientMessage), 0); //receive message from client
39.             printf("\nClient message: %s", clientMessage); //display message
40.         }
41.     } else {
42.         // Parent process (send message to client)
43.         while (1) {
44.             printf("Server: ");
45.             fgets(serverMessage, SIZE, stdin); //get message from keyboard
46.             send(client_socket, serverMessage, strlen(serverMessage), 0); //send message to client
47.         }
48.     }
49.  
50.     close(socketDescriptor);
51.     return 0;
52. }
53.  
54.  
55.  
56.  
57.  
58. #include <stdio.h>
59. #include <stdlib.h>
60. #include <sys/types.h>
61. #include <sys/socket.h>
62. #include <netinet/in.h>
63. #include <unistd.h>
64. #include <string.h>
65.  
66. #define SIZE 1000
67.  
68. int main() {
69.     int socketDescriptor = socket(AF_INET, SOCK_STREAM, 0);
70.  
71.     struct sockaddr_in serverAddress;
72.     serverAddress.sin_family = AF_INET;
73.     serverAddress.sin_port = htons(9002);
74.     serverAddress.sin_addr.s_addr = INADDR_ANY;
75.  
76.     connect(socketDescriptor, (struct sockaddr *)&serverAddress;, sizeof(serverAddress));
77.  
78.     pid_t pid = fork();
79.  
80.     if (pid < 0) {
81.         fprintf(stderr, "Fork failed\n");
82.         return 1;
83.     }
84.  
85.     if (pid == 0) {
86.         // Child process (client send message to server)
87.         char clientMessage[SIZE];
88.         while (1) {
89.             printf("Client: ");
90.             fgets(clientMessage, SIZE, stdin); //get message from keyboard
91.             send(socketDescriptor, clientMessage, strlen(clientMessage), 0); //send message to server
92.         }
93.     } else {
94.         // Parent process (receive message from server)
95.         char serverMessage[SIZE];
96.         while (1) {
97.             recv(socketDescriptor, &serverMessage;, sizeof(serverMessage), 0); //receive message from server
98.             printf("\nServer message: %s", serverMessage); //display message
99.         }
100.     }
101.  
102.     close(socketDescriptor);
103.     return 0;
104. }