Question

I’m writing simple server/client in c, where server temporary stores message from client and retrieve it when client request it.

The problem is when client receives message from server, the buffer acts kinda weird.
All i did is read as much as receive from server and print it on the screen, but somehow buffer was overwrited more than maximum size of buffer

in client

while((byteRead = recv(ssock, buffer, MAXBUF, 0)) > 0)
{
   if(byteRead <= 0)
       break;
    printf("%s", buffer);
}

where MAXBUF is 256. It keep contains some garbages so i examined the string size in buffer
and surprisingly

printf("%d READ vs %d buffer strlen \n", byteRead, strlen(buffer))

show me that byteRead is 256 but string length of buffer is 262.

Any idea??

P.s on server side, it reads file correctly and send it onto socket.

Answer 1

recv does not place a null terminator at the end of the string (whilst printf %s assumes there is one).

You must use byteRead to determine the length of the string. Add a null terminator if you want to use a function like printf, but ensure your buffer has the space for it even on a maximum-size read.