Advanced, easy to use, asynchronous-capable DNS client library and
utilities.
- adns is a resolver library for C (and C++) programs. In contrast with
- the existing interfaces, gethostbyname et al and libresolv, it has the
- following features:
+ adns is a resolver library for C (and C++) programs, and a collection
+ of useful DNS resolver utilities. In contrast with the existing
+ interfaces, gethostbyname et al and libresolv, it has the following
+ features:
* It is reasonably easy to use for simple programs which just want
to translate names to addresses, look up MX records, etc.
* It can be used in an asynchronous, non-blocking, manner. Many
* Understands conventional resolv.conf, but this can overridden by
environment variables.
* Flexibility. For example, the application can tell adns to: ignore
- environment variables (for setuid programs), disable sanity checks
- eg to return arbitrary data, override or ignore resolv.conf in
- favour of supplied configuration, etc.
+ environment variables (for setuid programs), disable hostname
+ syntax sanity checks to return arbitrary data, override or ignore
+ resolv.conf in favour of supplied configuration, etc.
* Believed to be correct ! For example, will correctly back off to
TCP in case of long replies or queries, or to other nameservers if
several are available. It has sensible handling of bad responses
etc.
+DNS utility programs
+
adns also comes with a number of utility programs for use from the
command line and in scripts:
* adnslogres is a much faster version of Apache's logresolv program.
delaying the output. For example, you can usefully pipe the output
of netstat -n, tcpdump -ln, and the like, into it.
* adnshost is a general-purpose DNS lookup utility which can be used
- easily in shell scripts to do simple lookups. In a more advanced
- mode it can be used as a general-purpose DNS helper program for
- scripting languages which can invoke and communicate with
- subprocesses.
+ easily in from the command line and from shell scripts to do
+ simple lookups. In a more advanced mode it can be used as a
+ general-purpose DNS helper program for scripting languages which
+ can invoke and communicate with subprocesses. See the [1]usage
+ message for a summary of its capabilities.
-Forthcoming:
+Technical note
- A native Perl interface is in the works, thanks to Tony Finch.
-
- I hope that future versions may also have the following features:
- * The library should be useable by threads in a multithreaded
- program in a natural way. It should multiplex many threads'
- queries through a single query socket.
- * IPv6 support.
- * Some kind of awareness of DNSSEC.
- * Possibly some very limited caching behaviour.
-
- (Technical note: adns requires a real nameserver like [1]BIND or
- [2]Dents running on the same system or a nearby one, which must be
- willing to provide `recursive service'. I.e., adns is a `stub
- resolver'. All properly configured UN*X and GNU systems will already
- have such nameserver(s); they are usually listed in /etc/resolv.conf.)
+ adns requires a real nameserver like [2]BIND or [3]Dents running on
+ the same system or a nearby one, which must be willing to provide
+ `recursive service'. I.e., adns is a `stub resolver'. All properly
+ configured UN*X and GNU systems will already have such nameserver(s);
+ they are usually listed in /etc/resolv.conf.
Documentation
I'm afraid there is no manual yet. However, competent C programmers
- should be able to use the library based on the [3]commented adns.h
- header file.
+ should be able to use the library based on the [4]commented adns.h
+ header file, and the usage messages for the programs should be
+ sufficient.
Feedback
bug reports, there; otherwise send mail to
adns-bugreports@chiark.greenend.org.uk. If you'd prefer that your
message wasn't forwarded to the adns-bugreports list, send it to
- adns-maint@chiark.greendend.org.uk.
+ adns-maint@chiark.greenend.org.uk.
Mailinglists
important bugs, new versions, &c. The bug reports address mentioned
above is also a mailing list; feel free to subscribe to it.
- There are [4]archives and subscription web pages, or you can subscribe
+ There are [5]archives and subscription web pages, or you can subscribe
by sending mail containing the word `subscribe' to
adns-announce-REQUEST@chiark.greenend.org.uk or
adns-discuss-REQUEST@chiark.greenend.org.uk.
Download
- Available for download from [5]chiark.greenend.org.uk are:
- * The [6]current beta version as a gzipped tarfile.
- * [7]adns.h API header file with comments (currently there is no
+ Available for download from [6]chiark.greenend.org.uk are:
+ * The [7]current beta version as a gzipped tarfile.
+ * [8]adns.h API header file with comments (currently there is no
manual, sorry).
- * All versions released so far are also available via [8]anonymous
+ * All versions released so far are also available via [9]anonymous
FTP.
* A mirror of my CVS repository is available via rsync from
rsync.chiark.greenend.org.uk::ftp/users/ian/cvs-pub/adns (use FTP
- first to find your way around), or via [9]cvsweb.
+ first to find your way around), or via [10]cvsweb.
- adns is also available from the [10]GNU Project FTP servers and their
- [11]mirrors.
+ adns is also available from the [11]GNU Project FTP servers and their
+ [12]mirrors.
Copyright and licensing
This program and documentation is distributed in the hope that it will
be useful, but without any warranty; without even the implied warranty
of merchantability or fitness for a particular purpose. See the
- [12]GNU General Public License for more details.
+ [13]GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with adns, or one should be available above; if not, write to
- the [13]Free Software Foundation, 59 Temple Place - Suite 330, Boston,
+ the [14]Free Software Foundation, 59 Temple Place - Suite 330, Boston,
MA 02111-1307, USA, or email adns-maint@chiark.greenend.org.uk.
_________________________________________________________________
- [14]Ian Jackson / [15]adns-maint@chiark.greenend.org.uk; more [16]free
+ [15]Ian Jackson / [16]adns-maint@chiark.greenend.org.uk; more [17]free
software by me.
- [17]GNU home page; [18]chiark home page; [19]site or mirror home page
+ [18]GNU home page; [19]chiark home page; [20]site or mirror home page
This web page is Copyright (C)1996-2000 Ian Jackson. See the
- [20]Copyright/acknowledgements.
+ [21]Copyright/acknowledgements.
- Use any browser - [21]Campaign for a non-browser-specific WWW
+ Use any browser - [22]Campaign for a non-browser-specific WWW
References
- 1. http://www.isc.org/view.cgi?/products/BIND/index.phtml
- 2. http://www.dents.org/
- 3. http://www.chiark.greenend.org.uk/~ian/adns/adns.h.txt
- 4. http://www.chiark.greenend.org.uk/mailman/listinfo
- 5. http://www.chiark.greenend.org.uk/~ian/adns/
- 6. http://www.chiark.greenend.org.uk/~ian/adns/adns.tar.gz
- 7. http://www.chiark.greenend.org.uk/~ian/adns/adns.h.txt
- 8. ftp://ftp.chiark.greenend.org.uk/users/ian/adns/
- 9. http://www.chiark.greenend.org.uk/ucgi/~ijackson/cvsweb/adns/
- 10. http://www.gnu.org/
- 11. http://www.gnu.org/order/ftp.html
- 12. http://www.chiark.greenend.org.uk/~ian/COPYING.txt
- 13. http://www.fsf.org/
- 14. http://www.chiark.greenend.org.uk/
- 15. mailto:adns-maint@chiark.greenend.org.uk
- 16. http://www.chiark.greenend.org.uk/~ian/software/
- 17. http://www.gnu.org/
- 18. http://www.chiark.greenend.org.uk/
+ 1. http://www.chiark.greenend.org.uk/~ian/adns/usage/adnsresfilter_usage.text
+ 2. http://www.isc.org/view.cgi?/products/BIND/index.phtml
+ 3. http://www.dents.org/
+ 4. http://www.chiark.greenend.org.uk/~ian/adns/adns.h.txt
+ 5. http://www.chiark.greenend.org.uk/mailman/listinfo
+ 6. http://www.chiark.greenend.org.uk/~ian/adns/
+ 7. http://www.chiark.greenend.org.uk/~ian/adns/adns.tar.gz
+ 8. http://www.chiark.greenend.org.uk/~ian/adns/adns.h.txt
+ 9. ftp://ftp.chiark.greenend.org.uk/users/ian/adns/
+ 10. http://www.chiark.greenend.org.uk/ucgi/~ijackson/cvsweb/adns/
+ 11. http://www.gnu.org/
+ 12. http://www.gnu.org/order/ftp.html
+ 13. http://www.chiark.greenend.org.uk/~ian/COPYING.txt
+ 14. http://www.fsf.org/
+ 15. http://www.chiark.greenend.org.uk/
+ 16. mailto:adns-maint@chiark.greenend.org.uk
+ 17. http://www.chiark.greenend.org.uk/~ian/software/
+ 18. http://www.gnu.org/
19. http://www.chiark.greenend.org.uk/
- 20. http://www.chiark.greenend.org.uk/~ian/sw-www-copy.html
- 21. http://www.anybrowser.org/campaign/
+ 20. file://localhost/
+ 21. http://www.chiark.greenend.org.uk/~ian/sw-www-copy.html
+ 22. http://www.anybrowser.org/campaign/
<html><head><title>adns - advanced, alternative, asynchronous resolver</title>
<!--
- Note to GNU webmasters and others who might edit this page: This
- file is maintained in GNU CVS, and also served on the author's own
- system, under the URL http://www.chiark.greenend.org.uk/adns/
- Please ensure that all links continine to be correct both for
- www.gnu.org and chiark.
+ Note: this file is maintained in Ian Jackson's private CVS.
- If you check in a change, please inform
- webmaster@chiark.greenend.org.uk.
+ It is served on the GNU site and also from my own system, under the
+ URL http://www.chiark.greenend.org.uk/adns/ Please ensure that all
+ links continine to be correct both for www.gnu.org and chiark.
$Id$
-->
<p>
-adns is a resolver library for C (and C++) programs. In contrast with
-the existing interfaces, gethostbyname et al and libresolv, it has the
-following features:
+adns is a resolver library for C (and C++) programs, and a collection
+of useful DNS resolver utilities. In contrast with the existing
+interfaces, gethostbyname et al and libresolv, it has the following
+features:
<ul>
environment variables.
<li>Flexibility. For example, the application can tell adns to:
-ignore environment variables (for setuid programs), disable sanity
-checks eg to return arbitrary data, override or ignore resolv.conf in
-favour of supplied configuration, etc.
+ignore environment variables (for setuid programs), disable hostname
+syntax sanity checks to return arbitrary data, override or ignore
+resolv.conf in favour of supplied configuration, etc.
<li>Believed to be correct ! For example, will correctly back off to
TCP in case of long replies or queries, or to other nameservers if
</ul>
+<h2>DNS utility programs</h2>
+
adns also comes with a number of utility programs for use from the
command line and in scripts:
output of netstat -n, tcpdump -ln, and the like, into it.
<li><code>adnshost</code> is a general-purpose DNS lookup utility
-which can be used easily in shell scripts to do simple lookups. In a
-more advanced mode it can be used as a general-purpose DNS helper
-program for scripting languages which can invoke and communicate with
-subprocesses.
+which can be used easily in from the command line and from shell
+scripts to do simple lookups. In a more advanced mode it can be used
+as a general-purpose DNS helper program for scripting languages which
+can invoke and communicate with subprocesses. See the
+<A href="http://www.chiark.greenend.org.uk/~ian/adns/usage/adnsresfilter_usage.text">usage
+message</A> for a summary of its capabilities.
</ul>
-<h2>Forthcoming:</h2>
-
-A native Perl interface is in the works, thanks to Tony Finch.
-
-<p>
-
-I hope that future versions may also have the following features:
-
-<ul>
-
-<li>The library should be useable by threads in a multithreaded
-program in a natural way. It should multiplex many threads' queries
-through a single query socket.
-
-<li>IPv6 support.
-
-<li>Some kind of awareness of DNSSEC.
-
-<li>Possibly some very limited caching behaviour.
-
-</ul>
+<h2>Technical note</h2>
-(Technical note: adns requires a real nameserver like
+adns requires a real nameserver like
<A href="http://www.isc.org/view.cgi?/products/BIND/index.phtml">BIND</A>
or
<A href="http://www.dents.org/">Dents</A> running on
the same system or a nearby one, which must be willing to provide
`recursive service'. I.e., adns is a `stub resolver'. All properly
configured UN*X and GNU systems will already have such nameserver(s);
-they are usually listed in /etc/resolv.conf.)
+they are usually listed in /etc/resolv.conf.
<h2>Documentation</h2>
I'm afraid there is no manual yet. However, competent C programmers
should be able to use the library based on the
<A href="http://www.chiark.greenend.org.uk/~ian/adns/adns.h.txt">commented
-adns.h header file</A>.
+adns.h header file</A>, and the usage messages for the programs should
+be sufficient.
<h2>Feedback</h2>
~ianmdlvl / adns.git / commitdiff