Standard C Library (libc, -lc)

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);

DESCRIPTION

     This family of functions allows you to perform lookups of Hesiod informa-
     tion, 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 free().

RETURN VALUES

     The hesiod_init() function returns the value 0 if successful; otherwise
     the value -1 is returned and the global variable errno is set 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

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

     HESIOD_CONFIG  If the environment variable HESIOD_CONFIG is set, it spec-
                    ifies the location of the Hesiod configuration file.

     [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.

AUTHORS

     Steve Dyer, IBM/Project Athena
     Greg Hudson, MIT Team Athena

     Copyright 1987, 1988, 1995, 1996 by the Massachusetts Institute of Tech-
     nology.

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.

BSD                            November 30, 1996                           BSD