Before using the Ecore_Con library, it needs to be initialized.

#include <Ecore_Con.h>
// Init ecore_con library.
int ret = ecore_con_init();
// ret is the number of times the library has been initialized
// without shutdown.

We can do a simple DNS lookup using the following function:

EAPI Eina_Bool ecore_con_lookup(const char *     name,
                                Ecore_Con_Dns_Cb done_cb,
                                const void *     data
                               )

in which:

• name: the IP address or the server name to translate;
• done_cb: a callback to notify when the request is done;
• data: the data to be passed to the callback.

The done_cb function prototype is :

void done_cb(const char *      canonname,
             const char *      ip,
             struct sockaddr * addr,
             int               addrlen,
             void *            data
            )

where:

• canonname: the canonical name associated with the address;
• ip: the resolved IP address;
• addr: a pointer to the socket address;
• addrlen: the length of the socket address, in bytes;
• data: the data passed to the callback.

As an example, we want to know the canonical name of the 140.211.167.135 IP address. Let’s first declare the done_cb callback that will be called when the DNS lookup will finish.

static void
done_cb(const char *canonname, const char *ip, struct sockaddr *addr, int addrlen, void *data)
{
   printf("140.211.167.135 name is %s\n", canonname);
}

Then we can call the ecore_con_lookup() function to do the query.

// Call ecore_con_lookup.
ret = ecore_con_lookup("140.211.167.135", done_cb, NULL);
// If ret is EINA_FALSE the request failed to set up.

When the request succeeds it shall call the done_cb() callback that will printthe name associated with the IP address we gave.

When the library is not be used anymore, it has to be shut down.

// Shutdown the library.
ret = ecore_con_shutdown();