BASH::Filter file on mimetype

filter_on_mimetype-slimmed.sh

#!/bin/bash
# make sure the file exists and that it's a regular file before proceeding
[   -z "$1" ] && echo "you must specify a file!"  >&2 && exit 1
[ ! -e "$1" ] && echo "$1 doesn't exist!"         >&2 && exit 1
[ ! -f "$1" ] && echo "$1 is not a regular file!" >&2 && exit 1

FILE=$1
FILE_MIME=$(file -b --mime-type "$FILE") #or "xdg-mime query filetype"
VALID_MIMETYPES=(
  "application/octet-stream" #bmp image
  "application/pdf" #pdf
  "application/postscript" #ps
  "image/jpeg" #jpg image
  "image/png" #png image
  "image/tiff" #tiff image
  "text/plain" #text file
)

# searches for an element in the specified array and
# returns 0 if found, otherwise 1
# $1 is the element to search for
# $2 is the array
# source: patrik at http://stackoverflow.com/a/8574392
containsElement () {
  local e
  for e in "${@:2}"; do [[ "$e" == "$1" ]] && return 0; done
  return 1
}

if containsElement "$FILE_MIME" "${VALID_MIMETYPES[@]}"
then
  echo "do something with valid file"
else
  echo "do something with invalid file"
fi

filter_on_mimetype.sh

#!/bin/bash
FILE=$1
MIMETYPES=(
  "application/octet-stream" #bmp image
  "application/pdf" #pdf
  "application/postscript" #ps
  "image/jpeg" #jpg image
  "image/png" #png image
  "image/tiff" #tiff image
  "text/plain" #text file
)

#for more specific mimetype lookups see "xdg-mime query filetype"
getMimetype () {
  file -b --mime-type $1
}

# searches for an element in the specified array and
# returns 0 if found, otherwise 1
# $1 is the element to search for
# $2 is the array
# source: patrik at http://stackoverflow.com/a/8574392
containsElement () {
  local e
  for e in "${@:2}"; do [[ "$e" == "$1" ]] && return 0; done
  return 1
}

if [ -e "$FILE" ]
then
  if [ -f "$FILE" ] && containsElement $(getMimetype "$FILE") "${MIMETYPES[@]}"
  then
    echo "do something with valid file"
  else
    echo "do something with invalid file or dir"
  fi
else
  echo "$FILE doesn't exist!"
fi