.\" $NetBSD: hesiod.3,v 1.1 1999/01/25 03:43:04 lukem Exp $ .\" $FreeBSD: src/lib/libc/net/hesiod.3,v 1.3 2001/10/01 16:08:55 ru Exp $ .\" .\" from: #Id: hesiod.3,v 18.104.22.168 1997/01/03 21:02:23 ghudson Exp # .\" .\" Copyright 1988, 1996 by the Massachusetts Institute of Technology. .\" .\" Permission to use, copy, modify, and distribute this .\" software and its documentation for any purpose and without .\" fee is hereby granted, provided that the above copyright .\" notice appear in all copies and that both that copyright .\" notice and this permission notice appear in supporting .\" documentation, and that the name of M.I.T. not be used in .\" advertising or publicity pertaining to distribution of the .\" software without specific, written prior permission. .\" M.I.T. makes no representations about the suitability of .\" this software for any purpose. It is provided "as is" .\" without express or implied warranty. .\" .Dd November 30, 1996 .Dt HESIOD 3 .Os .Sh NAME .Nm hesiod , .Nm hesiod_init , .Nm hesiod_resolve , .Nm hesiod_free_list , .Nm hesiod_to_bind , .Nm hesiod_end .Nd Hesiod name server interface library .Sh LIBRARY .Lb libc .Sh SYNOPSIS .In hesiod.h .Ft int .Fn hesiod_init "void **context" .Ft char ** .Fn hesiod_resolve "void *context" "const char *name" "const char *type" .Ft void .Fn hesiod_free_list "void *context" "char **list" .Ft char * .Fn hesiod_to_bind "void *context" "const char *name" "const char *type" .Ft void .Fn hesiod_end "void *context" .Sh 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 .Fa context , an opaque object which stores information used internally by the library between calls. .Fn hesiod_init initializes a context, storing a pointer to the context in the location pointed to by the .Fa context argument. .Fn hesiod_end frees the resources used by a context. .Pp .Fn hesiod_resolve is the primary interface to the library. If successful, it returns a list of one or more strings giving the records matching .Fa name and .Fa type . The last element of the list is followed by a .Dv NULL pointer. It is the caller's responsibility to call .Fn hesiod_free_list to free the resources used by the returned list. .Pp .Fn hesiod_to_bind converts .Fa name and .Fa type into the DNS name used by .Fn hesiod_resolve . It is the caller's responsibility to free the returned string using .Fn free . .Sh RETURN VALUES .Rv -std hesiod_init On failure, .Fn hesiod_resolve and .Fn hesiod_to_bind return .Dv NULL and set the global variable .Va errno to indicate the error. .Sh ENVIRONMENT .Bl -tag -width HESIOD_CONFIG .It Ev HES_DOMAIN If the environment variable .Ev HES_DOMAIN is set, it will override the domain in the Hesiod configuration file. .It Ev HESIOD_CONFIG If the environment variable .Ev HESIOD_CONFIG is set, it specifies the location of the Hesiod configuration file. .El .Sh SEE ALSO .Xr hesiod.conf 5 , .Xr named 8 .Rs .%T "Hesiod - Project Athena Technical Plan -- Name Service" .Re .Sh ERRORS Hesiod calls may fail because of: .Bl -tag -width Er .It Bq Er ENOMEM Insufficient memory was available to carry out the requested operation. .It Bq Er ENOEXEC .Fn hesiod_init failed because the Hesiod configuration file was invalid. .It Bq Er ECONNREFUSED .Fn hesiod_resolve failed because no name server could be contacted to answer the query. .It Bq Er EMSGSIZE .Fn hesiod_resolve or .Fn hesiod_to_bind failed because the query or response was too big to fit into the packet buffers. .It Bq Er ENOENT .Fn hesiod_resolve failed because the name server had no text records matching .Fa name and .Fa type , or .Fn hesiod_to_bind failed because the .Fa name argument had a domain extension which could not be resolved with type .Dq rhs\-extension in the local Hesiod domain. .El .Sh AUTHORS .An Steve Dyer , IBM/Project Athena .An Greg Hudson , MIT Team Athena .Pp Copyright 1987, 1988, 1995, 1996 by the Massachusetts Institute of Technology. .Sh BUGS The strings corresponding to the .Va errno values set by the Hesiod functions are not particularly indicative of what went wrong, especially for .Er ENOEXEC and .Er ENOENT .