idn software package provides Command line and Emacs interface to GNU Libidn, you can install in your Ubuntu 14.04 LTS (Trusty Tahr) 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 14 04 lts trusty tahr |
| Section | Miscellaneous |
| Package | idn |
| Version | 1.28-1ubuntu2.1 [amd64, i386], |
| Description | Command line and Emacs interface to GNU Libidn |
| Sub Section | misc |