#!/bin/sh

# Copyright © 2016  Mattias Andrée <maandree@member.fsf.org>
# 
# 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, either version 3 of the License, or
# (at your option) any later version.
# 
# 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, see <http://www.gnu.org/licenses/>.

# DEPENDENCIES: findutils, coreutils, sed, util-linux, linux, sh

# Frequent international traveller? Set up cron to run this every
# now and then. It will restart all your instances of radharc, and
# if you have a custom script in $PATH named radharc (as your should
# have) that figures out your location and starts radharc, radharc
# will br aware of your no location.


# Close all file descriptors (except stderr,) so that radharc does not inherity any.
for fd in $(ls -1 /dev/fd/); do
    if [ ! "$fd" = 2 ]; then
	eval "exec ${fd}<&-";
    fi
done

# Get the user's real UID, in a sh-portable way.
uid="$(cat /proc/self/status | grep '^Uid:' | cut -f 2)"

# Restart all instances of radharc.
for pid in pgrep -x -U $uid radharc; do
    # Open environ and cmdline and be sure that they we successfully opened.
    # It is possible that the process has exited.
    exec 3<proc/"$pid"/environ 2>/dev/null
    if [ ! $? = 0 ]; then
	continue
    fi
    exec 4<proc/"$pid"/cmdline 2>/dev/null
    if [ ! $? = 0 ]; then
	continue
    fi
    
    # Restart radharc
    (<&3 cat
     printf 'radharc\x00'
     <&4 xargs -0 printf '%s\n' | sed 1d | grep -v '^-n$' | xargs printf '%s\x00'
     printf '%s\x00' '-n'
     exec 3<&-
     exec 4<&-
    ) | (kill -KILL "$pid" ; exec xargs -0 setsid env -i -- <>/dev/null 2>/dev/null &)
done