#!/bin/sh
#
# slay 2.0 - kill all processes belonging to the specified user(s).
# originally by Chris Ausbrooks <fish@bucket.ualr.edu> 
# based on kall (a script of unknown origin)
# Heavily rewritten by Pawel Wiecek <coven@debian.org> for Debian

# Revision history:
# 0.99	First attempt.
# 1.0	Added Butthead.
# 1.1	Added retribution.
# 1.2	Added slayee notification.
# 2.0   Completely rewritten
# 2.1	Fix an *ugly* bug that caused slayer to be slain...
# 2.2, 2.3  Debian specific updates
# 2.4   Updated command line handler to avois username/signal name mismatches
# 2.5   Debian specific updates
# 2.6   Properly slay oneself, fixed misleading error messages
# 2.7   Set PATH to prevent all sorts of problems with it coming from outside
# 3.0   Exit with 127 instead of -1 in case of a missing parameter

PATH=/usr/sbin:/sbin:/usr/bin:/bin
export PATH

USER=`whoami`
SIGNAL='-KILL'
SLAYEE=''
ME=`basename $0`
COOL='0'

# this piece of nested ifs is added for Debian package only
if [ -f /etc/slay_mode ]
then
  if grep -q mean /etc/slay_mode
  then
    MODE='mean'
  fi
  if grep -q nice /etc/slay_mode
  then
    MODE='nice'
  fi
  if [ -z $SLAY_BUTTHEAD ]
  then
    if grep -q butthead /etc/slay_mode
    then
      SLAY_BUTTHEAD='on'
    fi
    if grep -q normal /etc/slay_mode
    then
      SLAY_BUTTHEAD='off'
    fi
  fi
else
  MODE='nice'
  if [ -z $SLAY_BUTTHEAD ]
  then
    SLAY_BUTTHEAD='off'
  fi
fi

# Command line handling.
while [ $# -gt 0 ]
do
 case $1 in
  -*)
   SIGNAL=$1
   ;;
  *)
   SLAYEE="$SLAYEE $1"
 esac
 shift
done

if [ "$SIGNAL" != "-clean" ]
then
  SIGSHOW="$SIGNAL"
else
  SIGSHOW="-TERM + -KILL"
fi

# Help for losers.
if [ "$SLAYEE" = "" -o "$SIGNAL" = "--help" ]
then
  echo "usage: $ME [-signal] name [name...]"
  if [ "$SLAY_BUTTHEAD" = "on" ]
  then
    echo "       Like, kills people and stuff."
    echo "       With -clean kicks ass first and then does real pain."
  else
    echo "       Kills all processes belonging to any of the given names."
    echo "       Use -clean as a signal name to kill with TERM first and then with KILL."
  fi
  exit 127
fi

# Misuse trap.
if [ "$USER" != "$(echo "${SLAYEE}" | tr -d ' ')" ]
then
  if [ "$USER" != "root" ]
  then
    if [ "$MODE" = "mean" ]
    then
      $0 -KILL $USER
    else
      if [ "$SLAY_BUTTHEAD" = "on" ]
      then
        echo "${ME}: Cut it out."
      else
        echo "${ME}: Only root gets to do that."
      fi
    fi
    exit 2
  fi
fi

# Main body.
for slayee in $SLAYEE
do
  if [ "$slayee" = "$USER" ]
  then
    if [ "$SLAY_BUTTHEAD" = "on" ]
    then
      echo "${ME}: Beavis, don't make me have to smack you."
    else
      echo "${ME}: Illegal operation."
    fi
  fi
  COOL="1"
  if [ "$SLAY_BUTTHEAD" = "on" ]
  then
    cat <<-_THEEND_ | write $slayee
	${ME}: ${SIGSHOW} is kicking ${slayee}'s butt!
	
	
	
	I'm kicking your butt.
	
	
	_THEEND_
  else
    cat <<-_THEEND_ | write $slayee
	${ME}: Sending ${SIGSHOW} signal to ${slayee}'s process(es)..."
	
	
	Your current session has been terminated.
	
	
	_THEEND_
  fi
  if [ "$SIGNAL" = "-clean" ]
  then
    su -m $slayee -c "kill -TERM -1"
    sleep 10
    su -m $slayee -c "kill -KILL -1"
  else
    if [ "$USER" != "root" ]
    then
      kill $SIGNAL -1
    fi
    su -m $slayee -c "kill $SIGNAL -1"
  fi
done 2>/dev/null

# Error message.
if [ $COOL = "0" ]
then
  if [ "$SLAY_BUTTHEAD" = "on" ]
  then
    echo "${ME}: How old are you, Beavis?"
  else
    echo "${ME}: Nothing done."
  fi
  exit 1
fi

# Non-error message.
if [ $COOL = "1" ]
then
  if [ "$SLAY_BUTTHEAD" = "on" ]
  then
    echo "${ME}: Whoa, I have the power supreme."
  else
    echo "${ME}: Done."
  fi
  exit 0
fi