hesiod(3) - NetBSD Manual Pages

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HESIOD(3)               NetBSD Library Functions Manual              HESIOD(3)


NAME

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


LIBRARY

     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(3).


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 indi-
     cate 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 configura-
     tion file.


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.


SEE ALSO

     hesiod.conf(5), named(8)

     Hesiod - Project Athena Technical Plan -- Name Service.


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.

NetBSD 9.4_STABLE             September 16, 2001             NetBSD 9.4_STABLE