hesiod_init

HESIOD(3)                                                            HESIOD(3)



NAME
       hesiod,  hesiod_init, hesiod_resolve, hesiod_free_list, hesiod_to_bind,
       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_end(void *context)

       cc file.c -lhesiod

DESCRIPTION
       This family of functions allows you to perform lookups of Hesiod infor-
       mation, 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  hes-
       iod_resolve.   It  is  the caller's responsibility to free the returned
       string using free.

RETURN VALUES
       If successful, hesiod_init returns 0; otherwise it returns -1 and  sets
       errno  to  indicate  the  error.   On  failure, hesiod_resolve and hes-
       iod_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 configu-
       ration 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.

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

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



                               30 November 1996                      HESIOD(3)