NAME    [Toc]    [Back]

       res_mkquery - Make query messages for name servers

SYNOPSIS    [Toc]    [Back]

       #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    [Toc]    [Back]

       Standard C Library (libc)

PARAMETERS    [Toc]    [Back]

       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.   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.  Specifies
 one of the following parameters: Specifies the  ARPA
       Internet.   Specifies  the Chaos network at MIT.  Requires
       one of the following values:  Host  address  Authoritative
       server  Mail  destination  Mail  forwarder  Canonical name
       Start of authority zone Mailbox  domain  name  Mail  group
       member  Mail  rename  name NULL resource record Well known
       service  Domain  name  pointer  Host  information  Mailbox
       information  Mail routing information User (finger) information
 User ID Group ID Points to the data that is sent to
       the  name server as a search key.  The data is stored as a
       character array.  Defines the size of the array pointed to
       by the data parameter.  Specifies a reserved and currently
       unused parameter.  Points to  a  location  containing  the
       query  message.   Specifies  the  length  of  the  message
       pointed to by the buffer parameter.

DESCRIPTION    [Toc]    [Back]

       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    [Toc]    [Back]

       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    [Toc]    [Back]

       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    [Toc]    [Back]

       Contains the name server and domain name.

SEE ALSO    [Toc]    [Back]

       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).



                                                   res_mkquery(3)