Script to clean Zombie processes up using gdb

zombie_slayer.sh

#!/bin/bash
##################################################################
# Script: Zombie Slayer
# Author: Mitch Milner
# Date:   03/13/2013 ---> A good day to slay zombies
#
# Requirements: yum install gdb / apt-get install gdb
#               permissions to attach to the parent process
#
# This script works by using a debugger to
# attach to the parent process and then issuing
# a waitpid to the dead zombie. This will not kill
# the living parent process.
##################################################################

clear
# Wait for user input to proceed, give user a chance to cancel script
echo "***********************************************************"
echo -e "This script will terminate all zombie process."
echo "***********************************************************"

# initialize variables
intcount=0
lastparentid=0

# remove old gdb command file
rm -f /tmp/zombie_slayer.txt

# create the gdb command file
echo "***********************************************************"
echo "Creating command file..."
echo "***********************************************************"
ls /proc | grep -P '\d' | while read PID; do
  state=$([ -f /proc/$PID/status ] && awk '/^State/{ print $2}' /proc/$PID/status)
  if [ "$state" != "D" ]; then
    continue
  fi
  intcount=$((intcount+1))
  parentid=$(awk '/^PPid/{ print $2}' /proc/$PID/status)
  zombieid=$PID

  if [ "$parentid" != "$lastparentid" ]; then
    if [ "$lastparentid" != "0" ]; then
      echo "detach" >> /tmp/zombie_slayer.txt
    fi
    echo "attach $parentid" >> /tmp/zombie_slayer.txt
  fi
  echo "call waitpid ($zombieid,0,0)" >> /tmp/zombie_slayer.txt
  lastparentid=$parentid
done

if [ "$lastparentid" != "0" ]; then
  echo "detach" >> /tmp/zombie_slayer.txt
fi

# Slay the zombies with gdb and the created command file
echo -e "\n\n"
echo "***********************************************************"
echo "Slaying zombie processes..."
echo "***********************************************************"
gdb -batch -x /tmp/zombie_slayer.txt
echo -e "\n\n"
echo "***********************************************************"
echo "Script complete."
echo "***********************************************************"

Modified the original script to get zombie processes from /proc, rather than ps, as I was trying to use this on a server where ps was hanging.

I also removed the confirmation prompt and did a little reformatting.

I guess, state != Z instead of D

Thanks for a great implementation of the idea!