Optimize big jpg scans using imagemagic and jpgoptim programs

optimize_jpg.sh

#/usr/bin/env bash

shopt -s nocasematch

function exec_code() {
file=$1
ext=${file: -4}
if [[ $ext == '.jpg' ]]; then
  echo ', a jpeg file, working on it'
  mv "$file" "old_$file"
  convert "old_$file" -resize '40%' "$file"
  jpegoptim -s --all-progressive -f "$file"
  rm "old_$file"
else
  echo ', not a jpeg file, ignoring'
fi
}

function ls_dir() {
dir=$1

cd "$dir"

for file in * ; do
  echo -n "Testing: $file"
  if [[ -d "$file" ]]; then
    echo -n ' it is a directory'
    if [[ "$file" != '.' && "$file" != '..' ]]; then
      echo -n ' and we are going inside'
      ls_dir "$file"
      cd ..
    fi
  else
    echo -n ' normal file, inspecting'
    exec_code "$file"
  fi
  echo -n "\n"
done
}

# no argument for a directory to use
if [ -z "$1" -a "$1" == "" ]; then
  ls_dir './'
else
  if [ -d "$1" ]; then
    ls_dir "$1"
  else
    echo "Invalid argument was provided: $1"
  fi
fi

shopt -u nocasematch