Socket unable to detect disconnect

Question

I have written a server code that accepts connection through a client over wifi. The wifi socket is opened on a Wifi Dongle which shows up as ttyAMA0.

I create a socket

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

Then I do the usual accept...

while(1)
        {
                new_fd = accept(sfd,(struct sockaddr*)&client_addr,&len);
               ...
        ...
        }

and in one of my reader threads I am doing this:

void* Command2Buff(void *args)
{
 ...
        while(1)
        {
                 ....
                clientBytes = recv(str_fd.new_conn_fd,&temp,1);
                if(clientBytes == 0 || clientBytes == -1)
                {
                   ...
                }
                globalCmdbuf[wr] = temp;
               
        }
}

So recv should detect that a remote connection has turned off. When I turn the wifi off from my Android phone the code on the embedded machine just hangs.

I turn on the wifi on Phone and I can connect to the socket yet there is no transfer of data.

1. I tried read instead of recv but didn't make any difference.
2. I have tried TCPALIVE option as well..still doesn't work.
3. Should I remove the INADDR_ANY and write specifically for wlan....in that case what should i write

serv_addr.sin_addr.s_addr = WLAN;

Answer 1

As per EJP' suggestions I used SO_RCVTIMEO to turn off the connection from my side.