Achieving local mutex via a lock file

purge_stale_lock.sh

#!/bin/bash

exec 0>&- # close stdin
exec 1>&- # close stdout - comment out this line to see debug message
exec 2>&- # close stderr

base='/tmp'
list=`find $base -type f -name '*.lock' -print 2>/dev/null`

for lockfile in $list; do
  # see if any process is opening this file
  `/usr/sbin/lsof $lockfile 2>/dev/null 1>/dev/null`
  if [[ "$?" -gt 0 ]]; then
    # delete
    echo "$lockfile is not in use, attempting to delete"
    `rm -r $lockfile`
    if [[ "$?" -eq 0 ]]; then
      echo "$lockfile deleted"
    fi
  fi
done