NAME

       hesiod, hesiod_init, hesiod_resolve, hesiod_free_list, hesiod_to_bind, hesiod_free_string,
       hesiod_end - Hesiod name server interface library

SYNOPSIS

       #include <hesiod.h>

       int hesiod_init(void **context)
       char **hesiod_resolve(void *context, const char *name,
            const char *type)
       void hesiod_free_list(void *context, char **list);
       char *hesiod_to_bind(void *context, const char *name,
            const char *type)
       void hesiod_free_string(void *context, char *str);
       char **hesiod_parse_result(void *context,
       unsigned const char *result, int rlen)
       void hesiod_end(void *context)

       cc file.c -lhesiod

DESCRIPTION

       This family of functions allows you to perform lookups of  Hesiod  information,  which  is
       stored  as  text  records  in the Domain Name Service.  To perform lookups, you must first
       initialize a context, an opaque object which stores information  used  internally  by  the
       library  between  calls.   hesiod_init  initializes  a  context,  storing a pointer to the
       context in the location  pointed  to  by  the  context  argument.   hesiod_end  frees  the
       resources used by a context.

       hesiod_resolve  is the primary interface to the library.  If successful, it returns a list
       of one or more strings giving the records matching name and type.  The last element of the
       list  is  followed  by  a  NULL  pointer.   It  is  the  caller's  responsibility  to call
       hesiod_free_list to free the resources used by the returned list.

       hesiod_to_bind converts name and type into the DNS name used by hesiod_resolve.  It is the
       caller's responsibility to free the returned string using hesiod_free_string.

       hesiod_parse_result parses the result of a name server query into text records.  It is the
       caller's responsibility to call  hesiod_free_list  to  free  the  resources  used  by  the
       returned list.

RETURN VALUES

       If  successful,  hesiod_init returns 0; otherwise it returns -1 and sets errno to indicate
       the error.  On failure, hesiod_resolve and hesiod_to_bind return NULL and set  the  global
       variable errno to indicate the error.

ENVIRONMENT

       If  the  environment variable HES_DOMAIN is set, it will override the domain in the Hesiod
       configuration file.  If the environment variable HESIOD_CONFIG is set,  it  specifies  the
       location of the Hesiod configuration file.

SEE ALSO

       `Hesiod - Project Athena Technical Plan -- Name Service', named(8), hesiod.conf(5)

ERRORS

       Hesiod calls may fail because of:

       ENOMEM Insufficient memory was available to carry out the requested operation.

       ENOEXEC
              hesiod_init failed because the Hesiod configuration file was invalid.

       ECONNREFUSED
              hesiod_resolve  failed  because  no  name  server  could be contacted to answer the
              query.

       EMSGSIZE
              hesiod_resolve or hesiod_to_bind failed because the query or response was  too  big
              to fit into the packet buffers.

       ENOENT hesiod_resolve failed because the name server had no text records matching name and
              type, or hesiod_to_bind failed because the name argument  had  a  domain  extension
              which could not be resolved with type ``rhs-extension'' in the local Hesiod domain.

       EINVAL hesiod_to_bind  failed  to  convert  the  resulting  domain  name  from UTF-8 to an
              internationalized domain name.

AUTHOR

       Steve Dyer, IBM/Project Athena
       Greg Hudson, MIT Team Athena
       Copyright 1987, 1988, 1995, 1996, 2000 by the Massachusetts Institute of Technology.

BUGS

       The strings corresponding to the  errno  values  set  by  the  Hesiod  functions  are  not
       particularly indicative of what went wrong, especially for ENOEXEC and ENOENT.

                                         30 November 1996                               HESIOD(3)