#! /bin/bash

# Copyright (C) 2006 Enrico Scholz <enrico.scholz@informatik.tu-chemnitz.de>
#  
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; version 2 of the License.
#  
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#  
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

t=$(dirname "${TCONN:-$HOME/.tconn/tconn}")
: ${TCONN_CFG:=$t/tconn}
: ${TCONN_LIB:=tconn.so}

cfg=$TCONN_CFG
test ! -e "$cfg" || . "$cfg"

base=$(basename "$0")
honor_argv=
case $base in
	(tconn)		honor_argv=1;;
	(tconn-*)	cmd=${base##tconn-};;
	(t*)		cmd=${base##t};;
	(*)		echo "Unknown invocation method '$base'; aborting..." >&2
			exit 1;;
esac

if test -n "$honor_argv"; then
    case $1 in
      (--help) cat <<EOF
Usage: tconn <program> <args>*

Executes '<program> <args>*' with an LD_PRELOADed 'tconn.so' library.
It reads '\$TCONN_CFG' where the used flavor of 'tconn.so' can be
configured by setting the '\$TCONN_LIB' environment variable. The
following flavors are supported:

TCONN_LIB=tconn.so           ... only connect(2) will be wrapped [default]
TCONN_LIB=tconn-localres.so  ... like 'tconn.so' but uses a local
                                 '\$TCONN/resolv.conf' instead of the
				 systemwide /etc/resolv.conf
TCONN_LIB=tconn-tcpdns.so    ... like 'tconn.so' but makes DNS queries
                                 over the proxy
TCONN_LIB=tconn-localtcp.so  ... uses a local '\$TCONN/resolv.conf' and
                                 makes DNS queries over the proxy
	 
When not set explicitly, '\$TCONN_CFG' evaluates to:

* the 'tconn' file in the directory where '\$TCONN' is located, when
  '\$TCONN' is set, or
* '\$HOME/.tconn/tconn' else


When argv0 (\$0) has the format 't<program>', or 'tconn-<program>' the
program '<program>' will be executed as 'tconn <program>'. This allows
shortcuts e.g. by creating a symlink like

| \$ ln -s /usr/bin/git \$HOME/bin/tgit

This make a 'tgit' available so that

| \$ tgit pull origin

has the same effect like

| \$ tconn git pull origin


This program is *NOT* part of the original transconnect package and
provided by Fedora Extras only.  Please report bugs about it at
https://bugzilla.redhat.com.
EOF
	exit 0
	;;
      (--)   shift;;
    esac

    test "$#" -ge 1 >/dev/null || {
      echo "Error: no program given for 'tconn'; try '--help' for more information" >&2
      exit 1
    }
    
    cmd=$1
    shift
fi

LD_PRELOAD=$TCONN_LIB \
    exec -- "$cmd" "$@"