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res_mkquery(3)
NAME
  res_mkquery - Make query messages for name servers

SYNOPSIS
  #include <sys/types.h>
  #include <netinet/in.h>
  #include <arpa/nameser.h>
  #include <resolv.h>

  int res_mkquery(
	  int query_type,
	  const u_char *domain_name,
	  int class,
	  int type,
	  const char *data,
	  int data_length,
	  const u_char *reserved,
	  u_char *buffer,
	  int buf_length );

LIBRARY
  Standard C Library (libc)

PARAMETERS
  query_type
      Specifies a query type.  The usual type is QUERY, but the parameter can
      be set to any of the query types defined in the arpa/nameser.h file.

  domain_name
      Points to the name of the domain.	 If the domain_name parameter points
      to a single label and the RES_DEFNAMES bit is set, as it is by default,
      the function appends domain_name to the current domain name.  The
      current domain name is defined by the name server in use or in the
      /etc/resolv.conf file.

  class
      Specifies one of the following parameters:

      C_IN    Specifies the ARPA Internet.

      C_CHAOS Specifies the Chaos network at MIT.

  type
      Requires one of the following values:

      T_A     Host address

      T_NS    Authoritative server

      T_MD    Mail destination

      T_MF    Mail forwarder

      T_CNAME Canonical name

      T_SOA   Start of authority zone

      T_MB    Mailbox domain name

      T_MG    Mail group member

      T_MR    Mail rename name

      T_NULL  NULL resource record

      T_WKS   Well known service

      T_PTR   Domain name pointer

      T_HINFO Host information

      T_MINFO Mailbox information

      T_MX    Mail routing information

      T_UINFO User (finger) information

      T_UID   User ID

      T_GID   Group ID

  data
      Points to the data that is sent to the name server as a search key.
      The data is stored as a character array.

  data_length
      Defines the size of the array pointed to by the data parameter.

  reserved
      Specifies a reserved and currently unused parameter.

  buffer
      Points to a location containing the query message.

  buf_length
      Specifies the length of the message pointed to by the buffer parameter.

DESCRIPTION
  The res_mkquery() function makes packets for name servers in the Internet
  domain.  The res_mkquery() function makes a standard query message and
  places it in the location pointed to by the buffer parameter.

  The res_mkquery() function is one of a set of subroutines that form the
  resolver, a set of functions that resolve domain names.  Global information
  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_mkquery() function returns the size of
  the query. If the query is larger than the value of the buf_length
  parameter, the function fails and returns a value of -1.

ERRORS
  If an error occurs during a resolver operation, the h_errno external
  variable is set.  Error code values and reasons are defined in <netdb.h>.

FILES
  /etc/resolv.conf
      Contains the name server and domain name.

SEE ALSO
  Functions: dn_comp(3), dn_expand(3), dn_find(3), dn_skipname(3),
  _getlong(3), _getshort(3), putlong(3), putshort(3), res_init(3),
  res_query(3), res_search(3), res_send(3).

Index for Section 3

Alphabetical listing for R

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