idn software package provides Command line and Emacs interface to GNU Libidn, you can install in your Ubuntu 12.04 LTS (Precise Pangolin) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install idn
idn is installed in your system.
Make ensure the idn package were installed using the commands given below,
$ sudo dpkg-query -l | grep idn *
You will get with idn package name, version, architecture and description in a table
| Distro | Ubuntu 12 04 lts precise pangolin |
| Section | Miscellaneous |
| Package | idn |
| Version | 1.23-2ubuntu0.1 [amd64, i386], |
| Description | Command line and Emacs interface to GNU Libidn |
| Sub Section | misc |