alived

#!/bin/sh

if [ -n "$ALIVED_BASHDEBUG" ]; then
	set -x
fi

usage() { echo "Usage: `basename $0` [-p port] [-vkr] <username> <path/to/script>" 1>&2
 echo "-p is for binding port, -v is for debug output and program does not daemonize" 1>&2
 echo "-k is kill daemon, -r is to restart it (close/open socket)" 1>&2
 echo ""
 echo "developer set ALIVED_DEBUG or ALIVED_BASHDEBUG for debugging"
 exit 1; }

pidf=`basename $0`.pid
pidpath=/run

kill_daemon()
{
	detectpid
	[ $? -gt 0 ] && echo "No pid file" && exit 1
	# try kill by pidfile
	local trykill=0
	if [ -f $pidpath/$pidf ]; then
		local pid=`head -1 $pidpath/$pidf`
		echo $pid
		kill -3 $pid &>/dev/null
		[ $? -gt 0 ] && trykill=1
	fi

	
	local handler=$(sed -n '3,3p' $pidpath/$pidf)

	rm -f $pidpath/$pidf

	# no? try to find in processlist
	if [ $trykill -ne 0 ]; then
		local pid=`ps aux|grep "socat"|grep -v grep|grep "$1"|awk '{print $2;}'`
		if [ .$pid. != .. ]; then
			kill -3 $pid &>/dev/null
			[ $? -gt 0 ] && echo "Cannot kill socat"
		fi
	fi
}

detectpid()
{
	[ ! -f $pidpath/$pidf ] && pidpath=$HOME && [ ! -f $pidpath/$pidf ] && return 1
	return 0
}

status()
{
	detectpid
	[ $? -gt 0 ] && echo "Not running, no pid file" && return 0
	local handler=$(sed -n '3,3p' $pidpath/$pidf)
	local pid0=`head -1 $pidpath/$pidf`
	ps aux|grep "socat"|grep -v grep|awk '{print $2;}'|grep $pid0 &>/dev/null
	[ $? -gt 0 ] && echo "Error! Pid file is present but process pid=$pid0 not found!" && return 1
	local pid=$(findsocatproc $1)
	[ $? -ne 0 ] && return 0
	[ $pid -ne $pid0 ] && echo "Error! Found another process running pid=$pid" && return 1
	return 0
}

findsocatproc()
{
	local result=`ps aux|grep "socat"|grep -v grep|grep "$1"|awk '{print $2;}'`
	echo $result
}


port=10101
restart=0
killd=0

which socat 2>&1 >/dev/null
[ $? -gt 0 ] && echo "Socat is not installed in default paths. Cannot run" && exit 1

while getopts ":p:vkrs" o; do
	case "${o}" in
		p) port=${OPTSARG} ;;
		v) ALIVED_DEBUG="yes" ;;
		k) killd=1 ; restart=0 ;;
		r) killd=1 ; restart=1 ;;
		s) status $handler; exit $? ;;
		*) usage ;;
	esac
done
#echo $OPTIND

shift $((OPTIND-1))
handler=$2
username=$1
socat_param="TCP-LISTEN:$port,crnl,reuseaddr,fork,tcpwrap EXEC:$handler,su-d=$username"

if [ -n "$ALIVED_DEBUG" ]; then
	socat_scream="-vv"
fi

if [ $killd -ne 0 ]; then
	kill_daemon $handler
	[ $restart -eq 0 ] && exit 0
fi

#echo $#

if [ $# -lt 2 ]; then
    echo "alived <username> <path/to/script>"
    exit 1
fi


if [ -n "$socat_scream" ]; then
	# no daemon debug mode
	socat $socat_scream $socat_param
	#$2 --port=$port --docroot=${2%/*}
else
	# daemonize
	socat $socat_param 2>&1 >/dev/null &
	pidn=$(findsocatproc $handler)
	echo "$pidn" > $pidpath/$pidf &>/dev/null
	exitstatus=0
	[ ! -f $pidpath/$pidf ] && exitstatus=1
	if [ $exitstatus -gt 0 ]; then
		exitstatus=0
		pidpath=$HOME
		echo "$pidn" > $pidpath/$pidf
		[ ! -f $pidpath/$pidf ] && exitstatus=1
		if [ $exitstatus -gt 0 ]; then
			echo "Cannot create pid file"
			kill -3 $pidn
			exit 2
		fi
	fi
	echo $port >> $pidpath/$pidf
	echo $2 >> $pidpath/$pidf
	# echo "daemonizing is off"
fi