Interview Questions

Code Sample: How to make a Socket a Listen-only Connection Endpoint - listen()

Beginners Guide to Sockets

(Continued from previous question...)

Code Sample: How to make a Socket a Listen-only Connection Endpoint - listen() 

/*
Code Sample: Make a Socket a Listen-only
Connection Endpoint - listen()
*/


#include &ltsys/types.h>
#include &ltsys/socket.h>

int listen(int s, int backlog)

/*
listen establishes the socket as a passive 
endpoint of a connection.  It does not
suspend process execution.
*/

/*
No messages can be sent through this socket.
Incoming messages can be received.
*/

/*
s is the file descriptor associated with 
the socket created using the socket() system 
call. backlog is the size of the queue
of waiting requests while the server is busy
with a service request. The current
system-imposed maximum value is 5.
*/

/*
0 is returned on success, -1 on error
 with errno indicating the problem.
*/


Example:

#include &ltsys/types.h>
#include &ltsys/socket.h>

int sockfd; /* socket file descriptor */

if(listen(sockfd, 5) < 0)
   printf ("listen error %d\n", errno);

(Continued on next question...)

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