hesiod, hesiod_init, hesiod_resolve, hesiod_free_list, hesiod_to_bind, hesiod_free_string,
hesiod_end - Hesiod name server interface library
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_free_string(void *context, char *str);
char **hesiod_parse_result(void *context,
unsigned const char *result, int rlen)
void hesiod_end(void *context)
cc file.c -lhesiod
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 information used internally by the
library between calls. hesiod_init initializes a context, storing a pointer to the con-
text 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 hes-
iod_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 hesiod_free_string.
hesiod_parse_result parses the result of a name server query into text records. It is the
caller's responsibility to call hesiod_free_list to free the resources used by the
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 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 specifies 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
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.
EINVAL hesiod_to_bind failed to convert the resulting domain name from UTF-8 to an inter-
nationalized domain name.
Steve Dyer, IBM/Project Athena
Greg Hudson, MIT Team Athena
Copyright 1987, 1988, 1995, 1996, 2000 by the Massachusetts Institute of Technology.
The strings corresponding to the errno values set by the Hesiod functions are not particu-
larly indicative of what went wrong, especially for ENOEXEC and ENOENT.
30 November 1996 HESIOD(3)