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RUNIDN(1)               FreeBSD 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.

           hese 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.

           he 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,
       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.

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)
Command Section