Question

I wrote the following code in order to make an echo server (data I write to stdout moves from my PC to server and back to my PC).The problem is that though echo is getting displayed on client’s terminal it is being displayed same number of times as is its length.

server.cpp

void reflect(int x)
{
int n;
int m;
char data[100];
cout<<"Entered reflect function"<<endl; 

for(;;)
{
n=read(x,data, 100); 
cout<<"Client sent "<<n<<endl; 

if(n>0)
{
    while(n>0)
    {
        m=write(x,data,n);
        n=n-m;
    }
cout<<"Successfully echoed back to client"<<endl;  
}
}//end of for loop
}

int main()
{
sockaddr_in serv;
bzero(&serv, sizeof(serv));
serv.sin_family=AF_INET;
serv.sin_port=htons(3345);
inet_aton("127.0.0.1", &(serv.sin_addr));

int servfd=socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
int x;
x=bind(servfd, (sockaddr*)(&serv), sizeof(serv));

cout<<"Bind returned"<<x<<endl; //this displays x as 0

listen(servfd, 5);
sockaddr cli;
int connfd;
pid_t id=-1;
socklen_t siz=sizeof(cli);
for(;;)
{
    if((connfd=accept(servfd, &cli, &siz))>=0)
         id=fork();

    if(id==0)
         reflect(connfd);

    else 
         continue;
}
}

client.cpp

int main()
{
int clifd;
clifd=socket(AF_INET,SOCK_STREAM, IPPROTO_TCP);
sockaddr_in serv;
bzero(&serv, sizeof(serv));
serv.sin_family=AF_INET;
serv.sin_port=htons(3345);
inet_aton("127.0.0.1", &(serv.sin_addr));

connect(clifd, (sockaddr*)(&serv), sizeof(serv));
int n,m;
char data[100];
char recvd[100];
for(;;)
{
    fgets(data, 100,stdin );
    n=strlen(data);
    cout<<"You have written "<<n<<endl;

    if(n>0)
    {
        while(n>0)
        {  
             m=write(clifd,data,n);
             n=n-m;
        }
    }

    n=read(clifd, recvd, 100);
    cout<<"Server echoed back "<<n<<endl; 

    if(n>0)
    {
        while(n>0)
        {
            m=fputs(data,stdout);  //gets displayed many times
            cout<<"m is"<<m<<endl; //gets displayed many times
            fflush(stdout);
            n=n-m;
        }
        //cout<<data<<endl;
    }
}
}

What is the problem?

Answer 1

fputs

Return Value
On success, a non-negative value is returned.
On error, the function returns EOF.

Maybe use write instead to get the number of bytes written