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)