Introduction to Libidn

Libidn is a package designed for internationalized string handling based on the Stringprep, Punycode, IDNA and TLD specifications defined by the Internet Engineering Task Force (IETF) Internationalized Domain Names (IDN) working group, used for internationalized domain names. This is useful for converting data from the system's native representation into UTF-8, transforming Unicode strings into ASCII strings, allowing applications to use certain ASCII name labels (beginning with a special prefix) to represent non-ASCII name labels, and converting entire domain names to and from the ASCII Compatible Encoding (ACE) form.

Package Information

Libidn Dependencies


Emacs-21.4a, pkg-config-0.20, GTK-Doc-1.6, a Java compiler—one of (looked for in this order) GCC-4.0.3 (for gcj and you must also have the gjdoc package installed), Jikes or JDK-1.5.0_10, and a C# compiler—Mono or DotGNU Portable.NET

User Notes:

Installation of Libidn

Install Libidn by running the following commands:

./configure --prefix=/usr &&

If you have teTeX-3.0 installed and wish to create a text version of the documentation, issue the following commands:

cd doc &&
makeinfo --plaintext -o libidn.txt libidn.texi &&
cd ..

To test the results, issue: make check.

Now, as the root user:

make install &&
find doc -name "Makefile*" -exec rm {} \; &&

install -v -m755 -d \
    /usr/share/doc/libidn-0.6.3/{api,java,specifications,tld} &&
install -v -m644 doc/components* \
                 doc/libidn.{pdf,ps,html} \
    /usr/share/doc/libidn-0.6.3 &&
install -v -m644 doc/reference/html/* \
    /usr/share/doc/libidn-0.6.3/api &&
install -v -m644 doc/specifications/* \
    /usr/share/doc/libidn-0.6.3/specifications &&
install -v -m644 doc/tld/* /usr/share/doc/libidn-0.6.3/tld &&
cp -v -R doc/java/* /usr/share/doc/libidn-0.6.3/java

If you created the text documentation, install it using the following command as the root user:

install -v -m644 doc/libidn.txt /usr/share/doc/libidn-0.6.3

Command Explanations

--enable-gtk-doc: Use this parameter if GTK-Doc is installed and you wish to rebuild the API documentation.


Installed Program: idn
Installed Libraries: libidn.{so,a} and optionally, Java and C# modules
Installed Directory: /usr/share/doc/libidn-0.6.3

Short Descriptions


is a command line interface to the internationalized domain name library.


contains a generic Stringprep implementation that does Unicode 3.2 NFKC normalization, mapping and prohibition of characters, and bidirectional character handling. Profiles for Nameprep, iSCSI, SASL and XMPP are included as well as support for Punycode and ASCII Compatible Encoding (ACE) via IDNA. A mechanism to define Top-Level Domain (TLD) specific validation tables, and to compare strings against those tables, as well as default tables for some TLDs are included.

Last updated on 2007-02-14 11:57:11 -0600