Convert image resource files from an iOS project to image resource files with correct names and in proper directories for an Android project

iosResourceToAndroid.sh

#!/bin/bash

if [ -z "$1" ]
then 
  echo "Please enter the directory where your ios resource files reside"
else
  if [ -z "$2" ]
  then
    echo "Please enter the base directory where you want your android resources to reside"
  else
    lowDir="$2/drawable-ldpi"
    mediumDir="$2/drawable-mdpi"
    highDir="$2/drawable-hdpi"
    extraHighDir="$2/drawable-xhdpi"

    mkdir -p "$lowDir"
    mkdir -p "$mediumDir"
    mkdir -p "$highDir"
    mkdir -p "$extraHighDir"

    for f in `ls $1/*.png`; do
      filename=$(basename "$f")
      extension="${filename##*.}"
      filename="${filename%.*}"
      filename="`echo $filename | tr "[:upper:]" "[:lower:]"`"
      filename="`echo ${filename//-/_}`"
      filename="`echo ${filename// /_}`"
      HOST=user1
      if  [[ $filename == *@2x* ]] ;
      then
          filename="`echo ${filename//@2x/}`"
          #Copy file to large and xlarge dir
          cp "$f" "$highDir/$filename.png"
          cp "$f" "$extraHighDir/$filename.png"
      else
        #Copy file to medium and small dir
        cp "$f" "$lowDir/$filename.png"
        cp "$f" "$mediumDir/$filename.png"
      fi
    done
  fi
fi