rc

#! /bin/sh
# This is the file "rc" which starts and stops services for the different
# runlevels of the SysV init.
#
# Author:       Winfried Trümper <winni@xpilot.org>
# Misc fixes by Tom Lees <tom@lpsg.demon.co.uk>.
# Misc improvements and code rewrite by Martin Schulze <joey@debian.org>
# Misc improvements by Roland Rosenfeld <roland@spinnaker.de>
# Partial rewrite by Alexander Wirt <formorer@debian.org>
#
#   Copyright (c) 1998  Martin Schulze <joey@debian.org>
#                 1998  Winfried Trümper <winni@xpilot.org>
#                 1998  Miquel van Smoorenburg <miquels@cistron.nl>
#            1999-2000  Roland Rosenfeld <roland@spinnaker.de>
#                 2010  Alexander Wirt <formorer@formorer.de>
#
# Unlike traditional implementations it avoids the messy scheme with
# expressing the setup through links but reads a central config file
# instead. From a technical point of view both methods are almost
# equivalent.
#
# To be compatible with the common configuration scheme in the Linux-world,
# every script has two states: "on" or "off". The effect of this is that
# once it is switched on, it is never started again when the runlevel changes
# (it is only executed to switch it off if necessary).
#

# 
# This scripts accept to different parameters, -v and -d. Please don't mix them
# -v means some verbose output during operations 
# -d means the same output, but also rc is doing a dry-run and does not try to 
#    start or stop anything. 
#
# The following section is taken from the original rc with slight
# modifications.

# Ignore CTRL-C only in this shell, so we can interrupt subprocesses.
trap ":" INT QUIT TSTP

# Set onlcr to avoid staircase effect.
stty onlcr 0>&1

debug=0
if [ "$1" = "-d" ]
then
    debug=1
    shift
fi

verbose=0 
if [ "$1" = "-v" ]
then
	verbose=1
	debug=1
	shift
fi

# Is this done because RUNLEVEL and PREVLEVEL could be read-only?
#
# Now find out what the current and what the previous runlevel are.
runlevel=$RUNLEVEL
  # Get first argument. Set new runlevel to this argument.
[ "$1" != "" ] && runlevel="$1"
  # Is this necessary?
prevlevel=${PREVLEVEL:="N"}
  # Is this necessary?
export runlevel previous

CFGFILE="/etc/runlevel.conf"
BAKCFG="/etc/runlevel.fallback"
LOCKFILE="/var/lock/runlevel.lock"

true=0
false=1

valid_min_seq=0
valid_max_seq=99

[ $debug -eq 1 ] && echo "rc: $prevlevel -> $runlevel"
  # wait for any lock to vanish (but only when not booting)
i=0
while [ -f "$LOCKFILE" ] && [ "$previous" != "N" ]
do
    read pid < "$LOCKFILE"
    if ! kill -s 0 $pid > /dev/null 2>&1
    then
	echo "$0: found stale lockfile '$LOCKFILE'. Ignoring it." >&2
	rm -f "$LOCKFILE"	# external command (does not work on R/O fs)
        break
    fi
    if [ "$i" -gt "60" ]
    then
        echo "Process no. '$pid' is locking the configuration database." >&2

	if [ "$runlevel" = "1" -o "$runlevel" = "6" ]
	then
	    # Try killing locking process, if booting, rebooting or halting.
	    echo "Sending TERM signal to $pid." >&2
	    kill -s 15 $pid
	    sleep 5
	    echo "Sending KILL signal to $pid." >&2	
	    kill -s 9 $pid > /dev/null 2>&1
	    rm -f "$LOCKFILE"	# external command (does not work on R/O FS)
	    sleep 5
	    break
	else
	    # Normal runlevel change (not boot, reboot or halt)
	    echo "Terminating." >&2
	    exit 1
	fi
    fi
    sleep 2
    echo -n "."
    i=$(($i + 1))
done


  # This script is vital so we better keep an old copy of the configuration
  # file as fallsave-configuration. This does not handle a broken config
  # file, though.
if [ ! -f "$CFGFILE" ]
then
    echo "Missing configuration file '$CFGFILE' using fallback config."

    if [ ! -f "$BAKCFG" ]
    then
	echo "No configuration file at all. You're in serious trouble now."
	echo "Please try to fix this problem with a root shell and reboot."
	if [ -f /etc/default/rcS ]
	then
	    # Read value of $CONSOLE:
	    . /etc/default/rcS
	fi
	/sbin/sulogin $CONSOLE
	exit 1
    fi
    CFGFILE="$BAKCFG"
fi

is_valid_sequence() {
    if [ $# -ne 1 ]
    then
	return $false
    fi

    case $1 in
    [0-9]|[0-9][0-9]) ;;
    *) return $false ;;
    esac

    if [ $1 -ge $valid_min_seq ] && [ $1 -le $valid_max_seq ]
    then
	return $true
    fi
    return $false
}

element() {
    element="$1"
    case "$element" in
	reboot | R) element=0 ;;
	halt   | H) element=6 ;;
    esac
	
    [ "$2" = "in" ] && shift
    list="$2"
    [ "$list" = "-" ] && return 1
    [ "$list" = "*" ] && return 0

    ORGIFS="$IFS"
    IFS=","
    set -- $list
    IFS="$ORGIFS"
    case $element in
	"$1" | "$2" | "$3" | "$4" | "$5" | "$6" | "$7" | "$8" | "$9")
	    return 0
    esac
    return 1
}

is_elem() {
    elem=$1; shift

    for x in $*
    do
	[ "$x" = "$elem" ] && return 0
    done
    return 1
}

# Adds new levels to list of levels of the given command.  The entire
# list of commands and levels is tested.
#
pushlevel() {
    newcmd=$1;shift
    newlevels=$1; shift
    add="$newcmd:$newlevels"
    outline=""

    for i in $*
    do
	cmd=${i%:*}
	if [ "$cmd" = "$newcmd" ]
	then
	    outline="$outline$i,$newlevels "
	    add=""
	else
	    outline="$outline$i "
	fi
    done
    echo "$outline$add"
}


  # CMDLIST ensures scripts are killed in reversed order
CMDLIST="set centerline=here"
STARTCMD=""
STOPCMD=""
  # Experimental: To tell the scripts they are not called manually.
  # (should be unset in init.d-scripts)
CALL_FROM_RC="yes"

[ $debug -eq 1 ] && echo "Reading configuration file $CFGFILE."

case $runlevel in
0|6)	start=stop; stop=stop;;
*)	start=start; stop=stop;;
esac


# lock the configuration file
if [ "$prevlevel" != "N" ] && [ "$runlevel" != "1" ] && [ "$runlevel" != "6" ]
then
    (echo "$$" > "$LOCKFILE") || true
fi

while read  SORT_NO  OFF_LEVELS  ON_LEVELS  CMD  OPTIONS
do
    case "$SORT_NO" in
	\#*|""|\#) continue ;;
    esac
    [ ! -f "$CMD" ] && continue
    is_valid_sequence "$SORT_NO" || continue

    # currently OPTIONS is completely ignored ... we _could_ pass them to the
    # init-script after "start" or "stop".

    [ "$ON_LEVELS" != "-" ] && element "$runlevel" in "$ON_LEVELS" \
	&& STARTLIST=`pushlevel $SORT_NO:$CMD $ON_LEVELS $STARTLIST`

    if ! element "$prevlevel" in "$OFF_LEVELS"; then
	    element "$runlevel" in "$OFF_LEVELS" && STOPLIST="$STOPLIST$SORT_NO:$CMD "
    fi

done < $CFGFILE

# remove lock of configuration file
if [ "$prevlevel" != "N" ] && [ "$runlevel" != "1" ] && [ "$runlevel" != "6" ]
then
    rm -f "$LOCKFILE"
fi


# First, run the KILL scripts.
for x in 0 1 2 3 4 5 6 7 8 9
do
  for y in 0 1 2 3 4 5 6 7 8 9
  do
    for script in $STOPLIST
    do
      STOP_NUM=${script%%:*}
      if [ $STOP_NUM -eq $x$y ]
      then
        CMD=${script#*:}
        if [ "$prevlevel" != "N" ]
        then
          case "$CMD" in
            *.sh)	CMDLIST="$CMDLIST; (set -- $stop; . $CMD)" ;;
            *)	[ -x "$CMD" ] && CMDLIST="$CMDLIST; $CMD $stop" 
                test $debug = 1 && echo "Stop $CMD" 
            ;;
          esac
        fi
      fi
    done
  done
done

# Then look at the start scripts
for x in 0 1 2 3 4 5 6 7 8 9
do
  for y in 0 1 2 3 4 5 6 7 8 9
  do
    for script in $STARTLIST
    do
      START_NUM=${script%%:*}
      if [ $START_NUM -eq $x$y ]
      then
        comb=${script#*:}
        CMD=${comb%:*}
        if [ "$prevlevel" != "N" ]
        then
          level=${comb#*:}
          if element "$prevlevel" in "$level" && ! is_elem $CMD $STOPLIST
          then
            continue
          fi
        fi
        case "$CMD" in
          *.sh) CMDLIST="$CMDLIST; (set -- $start; . $CMD)" ;;
          *)  [ -x "$CMD" ] && CMDLIST="$CMDLIST; $CMD $start"
          test $debug = 1 && echo "Start $CMD"
          ;;
        esac
      fi
    done
  done
done

# Execute the commands collected above
if test $debug -eq 1 && test $verbose -eq 0 
then
    echo "$CMDLIST"
else
    test $verbose -eq 1 && echo "$CMDLIST" 
    (trap - INT QUIT TSTP; sh -c "$CMDLIST")
fi