res_send(3)res_send(3)NAMEres_send - Send a query to a name server and retrieve a response
SYNOPSIS
#include <sys/types.h> #include <netinet/in.h> #include
<arpa/nameser.h> #include <resolv.h>
int res_send(
const u_char *msg_ptr,
int msg_len,
u_char *answer,
int ans_len );
LIBRARY
Standard C Library (libc)
PARAMETERS
Points to the beginning of a message. Specifies the length of the mes‐
sage. Points to an address where the response is stored. Specifies
the size of the answer area.
DESCRIPTION
The res_send() function sends a query to name servers and calls the
res_init() function if the RES_INIT option of the _resdata structure is
not set. This function sends the query to the local name server and
handles timeouts and retries.
The res_send() function is one of a set of subroutines that form the
resolver, a set of functions that resolve domain names. Global infor‐
mation that is used by the resolver functions is kept in the _res data
structure. The /include/resolv.h file contains the _res data structure
definition.
RETURN VALUES
Upon successful completion, the res_send() function returns the length
of the message. Otherwise, -1 is returned and the h_errno external
variable is set with an error code, if any. Error code values and rea‐
sons are defined in <netdb.h>.
FILES
Contains general name server and domain name information.
SEE ALSO
Functions: dn_comp(3), dn_expand(3), dn_find(3), dn_skipname(3), _get‐
long(3), _getshort(3), putlong(3), putshort(3), res_init(3),
res_mkquery(3), res_query(3), res_search(3).
res_send(3)