HESIOD(3) BSD Library Functions Manual HESIOD(3)
NAME
hesiod, hesiodinit, hesiodresolve, hesiodfreelist, hesiodtobind,
hesiodend -- Hesiod name server interface library
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
##include <>
int
hesiodinit(void **context);
char **
hesiodresolve(void *context, const char *name, const char *type);
void
hesiodfreelist(void *context, char **list);
char *
hesiodtobind(void *context, const char *name, const char *type);
void
hesiodend(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.
hesiodinit() initializes a context, storing a pointer to the context in
the location pointed to by the context argument. hesiodend() frees the
resources used by a context.
hesiodresolve() 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 NUL pointer.
It is the caller's responsibility to call hesiodfreelist() to free the
resources used by the returned list.
hesiodtobind() converts name and type into the DNS name used by
hesiodresolve(). It is the caller's responsibility to free the returned
string using free().
RETURN VALUES
The hesiodinit() 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, hesiodresolve() and hesiodtobind() return NUL
and set the global variable errno to indicate the error.
ENVIRONMENT
HESDOMAIN If the environment variable HESDOMAIN is set, it will
override the domain in the Hesiod configuration file.
HESIODCONFIG If the environment variable HESIODCONFIG is set, it spec-
ifies the location of the Hesiod configuration file.
SEE ALSO
hesiod.conf(5), named(8)
Hesiod - Project Athena Technical Plan -- Name Service.
ERORS
Hesiod calls may fail because of:
[ENOMEM] Insufficient memory was available to carry out the
requested operation.
[ENOEXEC] hesiodinit() failed because the Hesiod configuration
file was invalid.
[ECONREFUSED] hesiodresolve() failed because no name server could
be contacted to answer the query.
[EMSGSIZE] hesiodresolve() or hesiodtobind() failed because
the query or response was too big to fit into the
packet buffers.
[ENOENT] hesiodresolve() failed because the name server had no
text records matching name and type, or
hesiodtobind() 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
|