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SYNOPSIS
cc ... -lsocket
#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 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.
RETURN VALUES
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.
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 speci-
fies the location of the Hesiod configuration file.
SEE ALSO
`Hesiod - Project Athena Technical Plan -- Name Service',
named(ADMN), 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 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.
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 functions are not particularly indicative of what
went wrong, especially for ENOEXEC and ENOENT.
30 November 1996