Question

Create a Client/Server program in C language

Answer 1

SERVER CODE

#include <stdio.h>

#include <sys/socket.h>

#include <netinet/in.h>

#include <string.h>

int main()

{

int welcomeSocket, newSocket;

char buffer[1024];

struct sockaddr_in serverAddr;

struct sockaddr_storage serverStorage;

socklen_t addr_size;

/*---- Create the socket. The three arguments of socket are: ----*/

/* 1) Internet domain 2) Stream socket 3) Default protocol */

welcomeSocket = socket(PF_INET, SOCK_STREAM, 0);

/*---- Configure the settings of server address struct ----*/

/* Address family = Internet */

serverAddr.sin_family = AF_INET;

/* Set port number, using htons function to use proper byte order */

serverAddr.sin_port = htons(7891);

/* Set IP address to localhost */

serverAddr.sin_addr.s_addr = inet_addr("127.0.0.1");

/* Set all bits of the padding field to 0 */

memset(serverAddr.sin_zero, '', sizeof serverAddr.sin_zero);

/*---- Bind the address struct to the socket ----*/

bind(welcomeSocket, (struct sockaddr *) &serverAddr, sizeof(serverAddr));

/*---- Listen on the socket, with 5 max connection requests queued ----*/

if(listen(welcomeSocket,5)==0)

    printf("Listeningn");

else

    printf("Errorn");

/*---- Accept call creates a new socket for the incoming connection ----*/

addr_size = sizeof serverStorage;

newSocket = accept(welcomeSocket, (struct sockaddr *) &serverStorage, &addr_size);

/*---- Send message to the socket of the incoming connection ----*/

strcpy(buffer,"Hello Worldn");

send(newSocket,buffer,13,0);

return 0;

}

CLIENT CODE

#include <stdio.h>

#include <sys/socket.h>

#include <netinet/in.h>

#include <string.h>

int main(){

int clientSocket;

char buffer[1024];

struct sockaddr_in serverAddr;

socklen_t addr_size;

/*---- Create the socket. The three arguments are: ----*/

/* 1) Internet domain 2) Stream socket 3) Default protocol (TCP in this case) */

clientSocket = socket(PF_INET, SOCK_STREAM, 0);

/*---- Configure settings of the server address struct ----*/

/* Address family = Internet */

serverAddr.sin_family = AF_INET;

/* Set port number, using htons function to use proper byte order */

serverAddr.sin_port = htons(7891);

/* Set IP address to localhost */

serverAddr.sin_addr.s_addr = inet_addr("127.0.0.1");

/* Set all bits of the padding field to 0 */

memset(serverAddr.sin_zero, '', sizeof serverAddr.sin_zero);

/*---- Connect the socket to the server using the address struct ----*/

addr_size = sizeof serverAddr;

connect(clientSocket, (struct sockaddr *) &serverAddr, addr_size);

/*---- Read the message from the server into the buffer ----*/

recv(clientSocket, buffer, 1024, 0);

/*---- Print the received message ----*/

printf("Data received: %s",buffer);   

return 0;

}