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)