# The question about getaddinfo **URL:** \ **Category:** Ruby\ **Created:** [May 14, 2009, 10:29am UTC](https://www.ruby-forum.com/t/the-question-about-getaddinfo/167943 "2009-05-14T10:29:47Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![zq1956](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/z/bc79bd/32.png) [@zq1956](https://www.ruby-forum.com/u/zq1956)\ **Post date:** [May 14, 2009, 10:29am UTC](https://www.ruby-forum.com/t/the-question-about-getaddinfo/167943/1 "2009-05-14T10:29:47Z")
I use getaddinfo to get A machine’s hostname, in B machine,the result is correct. but in A machine,the result is just A machine’s name I use nslookup,the result is also correct. who can tell me why in A machine，the result is wrong? ---
**Author:** ![zq1956](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/z/bc79bd/32.png) [@zq1956](https://www.ruby-forum.com/u/zq1956)\ **Post date:** [May 14, 2009, 10:50am UTC](https://www.ruby-forum.com/t/the-question-about-getaddinfo/167943/2 "2009-05-14T10:50:22Z")
Hi, approx. 3-5 months ago I had similar problem. The guy who helped tried to help mes said that it works for him. Then he realized that he uses a newes version of ruby (1.9.something at that time). So my first suggestion would be to check (or to write) what version of ruby are you using. I solved the problem using external command (host). I hope it helped a bit. Cheers, V. ---
**Author:** ![zq1956](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/z/bc79bd/32.png) [@zq1956](https://www.ruby-forum.com/u/zq1956)\ **Post date:** [May 14, 2009, 12:18pm UTC](https://www.ruby-forum.com/t/the-question-about-getaddinfo/167943/3 "2009-05-14T12:18:27Z")
Qq Zz wrote: > I use getaddinfo to get A machine’s hostname, > in B machine,the result is correct. > but in A machine,the result is just A machine’s name > I use nslookup,the result is also correct. > who can tell me why in A machine，the result is wrong? You don’t even say what platform you’re on. If you’re on a Unix-like platform, then maybe you have something like 1.2.3.4 machineA [machineA.com](http://machineA.com) in /etc/hosts. ---
**Author:** ![zq1956](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/z/bc79bd/32.png) [@zq1956](https://www.ruby-forum.com/u/zq1956)\ **Post date:** [May 14, 2009, 12:46pm UTC](https://www.ruby-forum.com/t/the-question-about-getaddinfo/167943/4 "2009-05-14T12:46:47Z")
Brian C. wrote: > Qq Zz wrote: > > > I use getaddinfo to get A machine’s hostname, > > in B machine,the result is correct. > > but in A machine,the result is just A machine’s name > > I use nslookup,the result is also correct. > > who can tell me why in A machine，the result is wrong? > > You don’t even say what platform you’re on. If you’re on a Unix-like > platform, then maybe you have something like > > 1.2.3.4 machineA [machineA.com](http://machineA.com) > > in /etc/hosts. no,windows vista ---
**Author:** ![zq1956](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/z/bc79bd/32.png) [@zq1956](https://www.ruby-forum.com/u/zq1956)\ **Post date:** [May 14, 2009, 12:21pm UTC](https://www.ruby-forum.com/t/the-question-about-getaddinfo/167943/5 "2009-05-14T12:21:22Z")
From: “Qq Zz” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > I use getaddinfo to get A machine’s hostname, > in B machine,the result is correct. > but in A machine,the result is just A machine’s name > I use nslookup,the result is also correct. > who can tell me why in A machine，the result is wrong? I ran into something similar awhile back: [http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-core/13805](http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-core/13805) This is what I now use: ip = “208.77.188.166” result = Socket.getnameinfo( Socket.pack\_sockaddr\_in(0, ip) ) hostname = result ? result.first : ip Hope this helps, Bill ---
**Author:** ![zq1956](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/z/bc79bd/32.png) [@zq1956](https://www.ruby-forum.com/u/zq1956)\ **Post date:** [May 14, 2009, 12:49pm UTC](https://www.ruby-forum.com/t/the-question-about-getaddinfo/167943/6 "2009-05-14T12:49:02Z")
Bill K. wrote: > From: “Qq Zz” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > > > I use getaddinfo to get A machine’s hostname, > > in B machine,the result is correct. > > but in A machine,the result is just A machine’s name > > I use nslookup,the result is also correct. > > who can tell me why in A machine，the result is wrong? > > I ran into something similar awhile back: > [http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-core/13805](http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-core/13805) > > This is what I now use: > > ip = “208.77.188.166” > result = Socket.getnameinfo( Socket.pack\_sockaddr\_in(0, ip) ) > hostname = result ? result.first : ip > > Hope this helps, > > Bill the response is: address family for hostname not supported oh my god!!! ---
**Author:** ![zq1956](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/z/bc79bd/32.png) [@zq1956](https://www.ruby-forum.com/u/zq1956)\ **Post date:** [May 15, 2009, 6:11am UTC](https://www.ruby-forum.com/t/the-question-about-getaddinfo/167943/7 "2009-05-15T06:11:52Z")
Vladimir F. wrote: > Hi, > approx. 3-5 months ago I had similar problem. The guy who helped tried > to > help mes said that it works for him. Then he realized that he uses a > newes > version of ruby (1.9.something at that time). So my first suggestion > would > be to check (or to write) what version of ruby are you using. > I solved the problem using external command (host). I hope it helped a > bit. > > Cheers, > > V. 1.9.1 not work host? in windows? ---
**Author:** ![zq1956](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/z/bc79bd/32.png) [@zq1956](https://www.ruby-forum.com/u/zq1956)\ **Post date:** [May 14, 2009, 2:49pm UTC](https://www.ruby-forum.com/t/the-question-about-getaddinfo/167943/8 "2009-05-14T14:49:44Z")
From: “Qq Zz” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > the response is: address family for hostname not supported Hmm. I too get that error on Windows: ruby -v -rsocket -e “p Socket.getnameinfo(Socket.pack\_sockaddr\_in(0, ‘208.77.188.166’))” ruby 1.8.4 (2005-12-24) [i386-mswin32] -e:1:in `getnameinfo’: getnameinfo: address family for hostname not supported. (SocketError) from -e:1 ruby19 -v -rsocket -e “p Socket.getnameinfo(Socket.pack\_sockaddr\_in(0, ‘208.77.188.166’))” ruby 1.9.1p129 (2009-05-12) [i386-mswin32\_71] -e:1:in `getnameinfo': getnameinfo: The requested name is valid and was found in the database, but it does not have the correct associated data being resolved for. (SocketError) from -e:1:in `’ However it works on Linux: ruby -v -rsocket -e “p Socket.getnameinfo(Socket.pack\_sockaddr\_in(0, ‘208.77.188.166’))” ruby 1.8.6 (2008-07-17 patchlevel 279) [x86\_64-linux] [“[www.example.com](http://www.example.com)”, “0”] Hmm… dunno… ☹ Regards, Bill