REUWAS

/*

 C socket server example, handles multiple clients using threads

 Compile

 gcc server.c -lpthread -o server

*/

 

#include <stdio.h>
#include <string.h> //strlen
#include <stdlib.h> //strlen
#include <sys/socket.h>
#include <arpa/inet.h> //inet_addr
#include <unistd.h> //write
#include <pthread.h> //for threading , link with lpthread

//the thread function
void *connection_handler(void *);

int main(int argc , char *argv[])
{
 int socket_desc , client_sock , c;
 struct sockaddr_in server , client;

 //Create socket
 socket_desc = socket(AF_INET , SOCK_STREAM , 0);
 if (socket_desc == -1)
 {
 printf("Could not create socket");
 }

 puts("Socket created");

 //Prepare the sockaddr_in structure
 server.sin_family = AF_INET;
 server.sin_addr.s_addr = inet_addr("127.0.0.1");
 server.sin_port = htons( 8888 );

 //Bind
 if( bind(socket_desc,(struct sockaddr *)&server , sizeof(server)) < 0)
 {
 //print the error message
 perror("bind failed. Error");
 return 1;
 }
 puts("bind done");

 //Listen
 listen(socket_desc , 3);
 
 //Accept and incoming connection
 puts("Waiting for incoming connections...");
 c = sizeof(struct sockaddr_in);

 //Accept and incoming connection
 puts("Waiting for incoming connections...");
 c = sizeof(struct sockaddr_in);
 pthread_t thread_id;

 
 while( (client_sock = accept(socket_desc, (struct sockaddr *)&client, (socklen_t*)&c)) )
 {
 puts("Connection accepted");

 if( pthread_create( &thread_id , NULL , connection_handler , (void*) &client_sock) < 0)
 {
 perror("could not create thread");
 return 1;
 }

 //Now join the thread , so that we dont terminate before the thread
 //pthread_join( thread_id , NULL);
 puts("Handler assigned");
 }
 if (client_sock < 0)
 {
 perror("accept failed");
 return 1;
 }
 return 0;
}

 

/*

 * This will handle connection for each client

 * */

void *connection_handler(void *socket_desc)
{
 //Get the socket descriptor
 int sock = *(int*)socket_desc;
 int read_size;
 char *message , client_message[2000];

 //Send some messages to the client
 message = "Greetings! I am your connection handler ";
 write(sock , message , strlen(message));
 message = "Now type something and i shall repeat what you type ";
 write(sock , message , strlen(message));

 //Receive a message from client
 while( (read_size = recv(sock , client_message , 2000 , 0)) > 0 )
 {
 //end of string marker
 client_message[read_size] = ;

 //Send the message back to client
 write(sock , client_message , strlen(client_message));

 //clear the message buffer
 memset(client_message, 0, 2000);
 }

 if(read_size == 0)
 {
 puts("Client disconnected");
 fflush(stdout);
 }
 else if(read_size == -1)
 {
 perror("recv failed");
 }
 return 0;
} 


/*

 C socket client example, handles multiple clients using threads
 Compile
 gcc -o client client.c
 run using --> ./client 

*/

#include <stdio.h>
#include <sys/types.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>

void error(char *msg)
{
 perror(msg);
 exit(0);
}

int main(int argc, char *argv[])
{
 int sockfd, portno, n,p,count=0;
 struct sockaddr_in serv_addr;
 char buff[256],client[100],temp_buff[100];
 FILE *id;
 id = popen("id -n -u","r");
 fgets(client,100,id);
 strtok(client," ");
 portno = 8888;

 bzero((char *) &serv_addr, sizeof(serv_addr));

 sockfd = socket(AF_INET, SOCK_STREAM, 0);
 if (sockfd < 0)
 error("ERROR opening socket"); 
 bzero((char *) &serv_addr, sizeof(serv_addr));

 serv_addr.sin_family = AF_INET;
 serv_addr.sin_port = htons(portno);
 serv_addr.sin_addr.s_addr = inet_addr("127.0.0.1");

 //getnameinfo((struct sockaddr *)&serv_addr, sizeof serv_addr, host, sizeof host, service, sizeof service, 0);
 if (connect(sockfd,(struct sockaddr *)&serv_addr,sizeof(serv_addr)) < 0)
 error("ERROR connecting");
 while(1)
 {
 if (count == 0)
 {
 p = write(sockfd,client,strlen(client));
 if (p < 0)
 error("ERROR writing to socket");
 bzero(temp_buff,sizeof(temp_buff));
 n = read(sockfd,temp_buff,99);
 if (n < 0)
 error("ERROR reading from socket");
 count++;
 }
 else
 {
 printf("%s: ",client);
 bzero(buff,256);
 fgets(buff,255,stdin);
 n = write(sockfd,buff,strlen(buff));
 if (n < 0)
 error("ERROR writing to socket");
 if (buff[0] == q)
 {
 close(sockfd);
 break;
 }

 n = read(sockfd,buff,255);
 if (n < 0)
 error("ERROR reading from socket");
 printf("%s:%s",temp_buff,buff);
 }
 } 
 return 0;
}