HESIOD(3)                                               HESIOD(3)

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

       #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)

       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 infor-
       mation used internally by the library between calls.  hes-
       iod_init initializes a context, storing a pointer  to  the
       context  in  the  location pointed to by the context argu-
       ment.  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  ele-
       ment 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 free.

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

       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  speci-
       fies the location of the Hesiod configuration file.

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

       Hesiod calls may fail because of:

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

              hesiod_init failed because the Hesiod configuration
              file was invalid.

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

              hesiod_resolve 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 hes-
              iod_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.

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

       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                       1