cd-missing-mkdir

#!/bin/bash
# mkdir wrapper | Vivien Didelot and Spencer Tipping
# Licensed under the terms of the MIT source code license

# Keep a special file key in each directory we should nuke.
cd_autorm=$(basename "$(mktemp -u "$HOME/.cd-autorm-XXXXXXXXXXXXXXXX")")

cd_on '^!$' cd_make_permanent

function cd_make_permanent {
  if [[ -e "$cd_autorm" ]]; then
    echo "cd: $PWD is now permanent"
    rm -f "$cd_autorm"
  else
    echo "cd: $PWD is already permanent"
  fi
}

function cd_missing_fn {
  local target=$1
  if ! mkdir -p -- "$target"; then
    echo "cd: cannot create ephemeral directory $target"
    return 1
  fi

  touch -- "$target/$cd_autorm"
  echo "cd: created ephemeral directory $target; cd ! to make it permanent"
  cd_goto "$target"
}

function cd_missing_unfn {
  # Look for the autorm key. This tells us that we created the directory, so we
  # have the ability to nuke it.
  local mode=$1
  local from=$2
  local to=$3
  if [[ -e "$from/$cd_autorm" ]]; then
    rm "$from/$cd_autorm"
    if rmdir "$from" >& /dev/null; then
      echo "cd: removed empty ephemeral directory $from"
    else
      echo "cd: $from is nonempty; converted to permanent"
    fi
  fi
}