|Specify the applications local codeset. If the option is not specified, runidn guesses the codeset from the current locale. See the NOTE section for more details about local codeset.|
runidn is a small shell script that sets up an environment variable called LD_PRELOAD, so that an application dynamically links a shared library libidnkitres before any other shared libraries.
The library libidnkitres provides a special version of resolver functions which implement features for handling internationalized domain names. runidn replaces the following functions with the special version:
gethostbyname gethostbyname2 gethostbyaddr gethostbyname_r gethostbyname2_r gethostbyaddr_r getipnodebyname getipnodebyaddr freehostent getaddrinfo freeaddrinfo getnameinfo
By overriding them in the standard libraries with the special version provided by libidnkitres, runidn enables applications to use internationalized domain names.
o These API functions accept non-ASCII domain names encoded in the local codeset that the application is using. Also the result from these APIs may contain non-ASCII domain names. o The normalization and codeset conversion between applications local codeset and the codeset used in DNS protocol data are handled automatically, so users/applications need not worry about them.
Properties of internationalized DNS (such as the normalization or the codeset used on DNS protocol data) can be configured with the idnkits configuration file (idn.conf). See idn.conf(5) for details.
Unless -e option is specified, runidn tries to guess the applications local codeset from the applications current locale. However, sometimes it cannot guess the codeset correctly, for example if the application does not set the locale appropriately by calling setlocale(). In that case, you can explicitly specify the local codeset by setting an environment variable IDN_LOCAL_CODESET. See the section LOCAL CODESET in idn.conf(5) for details.
The idea of using LD_PRELOAD to replace some functions in the standard library was taken from runsocks script distributed as part of SOCKS5 reference implementation.
There are many cases where runidn does not work.
Your system must support LD_PRELOAD mechanism in the first place.
Due to security reasons, LD_PRELOAD mechanism is disabled for setuid programs in any sane systems. So runidn does not work for setuid programs such as ping or rsh.
If your application uses a function other than the ones runidn supports for name resolution, you lose.
|-->||RUNIDN (1)||April 6, 2001|