ChatBox using socket programming in c

SERVER CODE

Save It With server.c

/*
*   Usage :  ./server <SERVER IP ID> <PORT NU.> 
*       Use port number between 5000 to 65535
*/

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

main(int argc,char **argv)
{

    int sfd, nfd, portno;
    char a[25];
    char reply[100];
    struct sockaddr_in v,v1;
    int  n;
    int size=0;
    FILE *in=NULL;
    char server[256],client[256];

    in=popen("id -n -u", "r");
    fgets(server,100, in);
    strtok(server, "\n");
    //printf("%s",server);

    //socklen_t n;

    // First call to socket() function /
    sfd = socket(AF_INET, SOCK_STREAM, 0);
    if(sfd<0)
    {
        perror("socket");
    }

    v.sin_family = AF_INET;
    v.sin_addr.s_addr =inet_addr(atoi(argv[1]));   /////server ip add
    v.sin_port = htons(atoi(argv[2])); ///// port num

    bind(sfd, (struct sockaddr *) &v, sizeof(v));
    perror("bind");   

    listen(sfd,1);
    perror("listen");   

    n=sizeof(v1);
    printf("n=%d\n",n);
    int cnt = 0;
    nfd = accept(sfd, (struct sockaddr *) &v1, &n);
    perror("accept");   

    while(1)
    {
        if(cnt==0)      //if condition transfer user name on client side.
        {   
            read(nfd,a,sizeof(a));
            strcpy(client,a);
            bzero(a,sizeof(a));
            cnt++;
            send(nfd,server,strlen(server)+1,0);
        }
        else            // else condition use for normal cheting.
        {
            bzero(a,sizeof(a));
            recv(nfd,a,sizeof(a),0);
            if(a[0]=='q')
            {
                close(nfd);
                break;
            }

        
            printf("%s-->%s",client,a);
                sleep(1);
            printf("%s:",server);
            bzero(reply,sizeof(reply));
            fgets(reply,sizeof(reply),stdin);
            send(nfd,reply,strlen(reply)+1,0);
        }
        
    }
}

CLIENT CODE

Save It With client.c

/*
*   Usage :  ./client <SERVER IP ID> <PORT NU.> 
*       Use port number between 5000 to 65535
*/


#include <stdio.h>
#include <sys/types.h> 
#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>
main(int argc,char **argv)
{

    int sfd, nfd, portno, clilen;
    char a[25],b[25];
    struct sockaddr_in v;
    int  n;
    int size=0;
    FILE *in=NULL;
    char client[256],server[256];

    in=popen("id -n -u", "r");
    fgets(client,100, in);
    strtok(client, "\n");

    // First call to socket() function /
    sfd = socket(AF_INET, SOCK_STREAM, 0);

    v.sin_family = AF_INET;
    v.sin_addr.s_addr =inet_addr(atoi(argv[1]));
    v.sin_port = htons(atoi(argv[2]));
    bind(sfd, (struct sockaddr *) &v,  sizeof(v));

    n=sizeof(v);
    printf("n=%d\n",n);
    int cnt =0;
    connect (sfd, (struct sockaddr *)&v , n);
    perror("connect");

    while(1)
    {   
        if(cnt == 0)            //if condition transfer user name on client side.
        {   
            write (sfd,client,strlen(client)+1);
            bzero(b,sizeof(b));
            cnt++;
            sleep(1);
            recv(sfd,b,sizeof(b),0);
            strcpy(server,b);
        }
        else                // else condition use for normal cheting.
        {
            printf("%s>>",client);
            fgets(a,sizeof(a),stdin);

            if(a[0]=='q')
            {
                close(sfd);
                break;
            }
        
            write (sfd,a,sizeof(a));
            sleep(1);
            bzero(b,sizeof(b));
            read(sfd,b,sizeof(b));
            printf("%s:%s",server,b);
        }
    }
    
}