auto remove directory after SIGNAL or exit

tmpdir_maker.sh

#!/bin/sh

export MEM_ROOT=/dev/shm
export MEM_DIR=$MEM_ROOT/$PBS_JOBID

# create directory per job
mkdir -p $MEM_DIR

# cleanup function
function mem_dir_cleanup {
  # try to be extra careful with rm
  if [[ $MEM_DIR == "$MEM_ROOT"* ]] ; then
    echo "cleaning up memdir: $MEM_DIR"
    rm --one-file-system --preserve-root -rf $MEM_DIR 
  else
    echo "$MEM_DIR looks bad, not cleaning up"
  fi
}

# do the cleanup, no matter how we exit (EXIT should catch all the signals)
trap mem_dir_cleanup EXIT PIPE

# now we can use MEM_DIR do whatever we want
# do some heavy work
sleep 30

# orderly cleanup should be the normal thing
mem_dir_cleanup