res_send()

The res_send() call sends a query to a local name server.

Syntax

#include <types.h>
#include <netinet\in.h>
#include <arpa\nameser.h>
#include <resolv.h>
int res_send(msg, msglen, ans, anslen)
char *msg;
int msglen;
char *ans;
int anslen;

Parameters

msg

Pointer to the beginning of a message.

Length of the buffer in bytes pointed to by the msg parameter.

Pointer to the location where the received response is stored.

Length of the buffer in bytes pointed by the ans parameter.

Description

This call sends a query to the local name server and calls the res_init() call if the RES_INIT option of the global _res structure is not set. It also handles timeouts and retries.

The res_send() call is one of a set of calls that form the resolver. The resolver is a group of functions that perform a translation between domain names and network addresses. Global information used by the resolver calls resides in the _res data structure. The <RESOLV.H> file contains the _res data structure definition. (See The _res Data Structure for more on the _res data structure.)

Return Values

When successful, the call returns the length of the message. When unsuccessful, the call returns a value of -1.

Related Calls

dn_comp() dn_expand()
dn_find()
dn_skipname()


• getlong()
  
• getshort()
  putlong()
  putshort()
  res_init()
  res_mkquery()
  res_query()
  res_search()