#!/bin/bash
set -e
function _help() {
  echo '
Usage: is-mount path

  Checks if path is the mountpoint root folder

  example:  is-mount -v /mnt/mountpoint

  -v for verbose output

  if path is a mountpoint: exit 0
  If path is not a mountpoint: exit 10
  if path is missing: exit 1
  '
  exit
}
verbose=0
for (( i=1; i<=$#; i++ ))
do  if [[ "${!i}" = "-h" ]]; then _help; fi
    if [[ "${!i}" = "-v" ]]; then verbose=1; continue; fi
    if [[ -z "$path1" ]]; then path1="${!i}"; continue; fi
done
if [[ -z "$path1" ]]; then _help; fi

if [[ ! -e "$path1" ]]; then
  echo "No such path '$path1'"
  exit 1
fi

path1=$( realpath "$path1" )

mountpoint1=$( stat -c "%m" "$path1" )

if [[ "$path1" = "$mountpoint1" ]]; then
  if [[ $verbose -eq 1 ]]; then
    echo "$path1 is a mount point"
  fi
  exit 0
fi
if [[ $verbose -eq 1 ]]; then
    echo "$path1 is not a mount point (it is $mountpoint1)"
  fi
exit 10