//This code is written by Souvik Ghosh and Debmitra Chatterjee
//Client Program in C
#include <sys/types.h>
#include <sys/socket.h>
#include <stdio.h>
#include <sys/un.h>
#include <unistd.h>
#include <stdlib.h>
int main(){
int sockfd;
int len;
struct sockaddr_un address;
int result;
int size;
sockfd = socket(AF_UNIX, SOCK_STREAM, 0);
address.sun_family = AF_UNIX;
strcpy(address.sun_path, "server_socket");
len = sizeof(address);
result = connect(sockfd, (struct sockaddr *)&address, len);
//Connect to the server
if(result == -1){
perror("connection failed!!");
exit(1);
}
printf("connected\n");
//user input
printf("please enter the number of integers you want to send: ");
scanf("%d",&size);
int numbers[size];
int sortedNumbers[size];
printf("please enter %d numbers: ",size);
for(int i=0;i<size;i++){
scanf("%d",&numbers[i]);
}
//read and write via sockfd
write(sockfd,&size,sizeof(int));
write(sockfd,&numbers,size*sizeof(int));
printf("numbers sent\n");
printf("waiting for the server...\n");
read(sockfd,&sortedNumbers,size*sizeof(int));
printf("numbers received: ");
for(int i=0;i<size;i++){
printf("%d ",sortedNumbers[i]);
}
printf("\n");
// close the socket connection
close(sockfd);
exit(0);
return 0;
}

//This code is written by Souvik Ghosh and Debmitra Chatterjee
//Server Program in C
#include <sys/types.h>
#include <sys/socket.h>
#include <stdio.h>
#include <sys/un.h>
#include <unistd.h>
#include <stdlib.h>
#define maxSize 100
/*predefined structure
struct sockaddr_un{
       //AF_UNIX
       sa_family_t sun_family;
       //Pathname
       char sun_path[108];
    };
*/
//swap function for sorting
void swap(int* xp, int* yp)
{
    int temp = *xp;
    *xp = *yp;
    *yp = temp;
}
// Function to perform Selection Sort
void selectionSort(int arr[], int n)
{
    int i, j, min_idx;
    // One by one move boundary of unsorted subarray
    for (i = 0; i < n - 1; i++) {
        // Find the minimum element in unsorted array
        min_idx = i;
        for (j = i + 1; j < n; j++)
            if (arr[j] < arr[min_idx])
                min_idx = j;
        // Swap the found minimum element
        // with the first element
        swap(&arr[min_idx], &arr[i]);
    }
}
int main(){
int server_sockfd, client_sockfd;
int server_len, client_len;
struct sockaddr_un server_address;
struct sockaddr_un client_address;
//The file should be deleted by the caller when it is no longer needed. AF_UNIX sockets can be deleted with unlink().
unlink("server_socket");
//SOCK_STREAM/SOCK_DGRAM, AF_UNIX(Unix file system )/AF_INET(Internet domain )
server_sockfd = socket(AF_UNIX, SOCK_STREAM, 0);
//This socket family is used to communicate between processes on the same machine.
server_address.sun_family = AF_UNIX;
//The file name referred to in addr.sun_path is created as a socket in the system file
strcpy(server_address.sun_path, "server_socket");
server_len = sizeof(server_address);
// bind a name to a socket
// Server ask the OS to enter information in the socket
// RETURN VALUE- On success, zero is returned.  On error, -1 is returned
bind(server_sockfd,(struct sockaddr *)&server_address, server_len);
//listen the requests comming from the client
// 5,backlog - the no of connections allowed in the queue. It can never be zero
listen(server_sockfd, 5);
while(1){
int n;
printf("server waiting.....\n");
client_len = sizeof(client_address);
//connection gets established here
client_sockfd = accept(server_sockfd,(struct sockaddr *)&client_address,&client_len);
//read
read(client_sockfd,&n,sizeof(int));
int receivedMessage[n];
read(client_sockfd,&receivedMessage,n*sizeof(int));
printf("numbers received: ");
for(int i=0;i<n;i++){
printf("%d ",receivedMessage[i]);
}
printf("\n");
//perform operation
selectionSort(receivedMessage,n);
printf("numbers sent: ");
for(int i=0;i<n;i++){
printf("%d ",receivedMessage[i]);
}
printf("\n");
//write
write(client_sockfd,&receivedMessage,n*sizeof(int));
// close the socket connection
close(client_sockfd);
}
return 0;
}