server.c

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


    //Learning socket programming
void error(const char *msg){
    perror(msg);
    exit(1);
}

int main(int argc,char *argv[]){
    if(argc<2){
        fprintf(stdout,"port number not provided.Program terminated\n");
        exit(1);
    }
    int sockfd , newsockfd ,portno,n;
    char buffer[256];
    struct sockaddr_in serv_addr , cli_addr;
    socklen_t clilen;

    sockfd=socket(AF_INET,SOCK_STREAM,0);
    if(sockfd<0){
        error("Error opening socket");
    }
    bzero((char *)&serv_addr,sizeof(serv_addr));
    portno = atoi(argv[1]);

    serv_addr.sin_family = AF_INET;
    serv_addr.sin_addr.s_addr = INADDR_ANY;
    serv_addr.sin_port = htons(portno);

    if(bind(sockfd,(struct sockaddr *)&serv_addr,sizeof(serv_addr))<0){
        error("Binding Failed");

    }
    listen(sockfd,5);
    clilen = sizeof(cli_addr);

    newsockfd = accept(sockfd,(struct sockaddr *)&cli_addr,&clilen);

    if(newsockfd<0){
        error("Error on Accepting the Connection");
    }
    while(1){
        bzero(buffer,256);
        n= read(newsockfd,buffer,256);
        if(n<0){
            error("Error on Reading.");
        }
        printf("Client : %s \n",buffer);
        bzero(buffer,256);
        fgets(buffer,256,stdin);
        n = write(newsockfd,buffer,strlen(buffer));
        if(n<0){
            error("Error on Writing");

        }
        int i = strncmp("Bye", buffer ,3);
        if(i == 0){
            break;

        }

    }
        close(newsockfd);
        close(sockfd);
    return 0;
    







}