RUNIDN(1)						      General Commands Manual							 RUNIDN(1)

NAME

       runidn - A script to allow applications to use internationalized domain names.

SYNOPSIS

       runidn [-e local-codeset] program-name [args..]

DESCRIPTION

       runidn  enables applications to use internationalized domain names without recompilation.  Just add ``runidn'' before the application-name,
       and the application can handle non-ASCII domain names.  For example, you can do:

	   % runidn telnet non-ASCII-hostname

       Before using runidn, you should set up properties related to internationalized DNS by configuring  idnkit's  configuration  file  idn.conf.
       See idn.conf(5) which describes the configuration.

OPTION

       The following option is available:

       -e local-codeset
	   Specify  the application's 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.

IMPLEMENTATION

       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 application's 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
       idnkit's configuration file (idn.conf).	See idn.conf(5) for details.

NOTE

       Unless -e option is specified, runidn tries to guess the application's local codeset from the application's current locale.  However, some-
       times 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.

BUGS

       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.

SEE ALSO

       idn.conf(5), runsocks(1)

								   April 6, 2001							 RUNIDN(1)