Rename batches of files

batchrename

#!/bin/bash

function usage() {
  echo "USAGE:  batchrename.sh <query> <replacement> [shouldMove]"
  echo -e "\n\
  Rename a batch of files. The first parameter (query) should be a\n\
  string common to all the filenames in the batch. The second\n\
  parameter (replacement) should be a string that replaces the\n\
  query in the new filenames. The third parameter indicates whether\n\
  it should copy or move the files. It defaults to false.\n\
  \n\
  EXAMPLE:  batchrename.sh 'IMG_' 'Family_Vacation_2018_' true\n"
}

query=$1
replacement=$2
shouldMove=$3

# If either of the first two parameters are empty
if [[ -z "${1// }" || -z "${2// }" ]]; then
  usage
  exit 1
fi

# shouldMove defaults to false
if [ -z "$3" ]; then
  shouldMove=false
fi

# If there exists a file that matches the pattern...
if [ -f *"${query}"* ]; then
  for filename in *"${query}"*; do
    newFilename=$(echo $filename | sed "s/${query}/${replacement}/")
    if $shouldMove; then
      echo "mv ${filename} ${newFilename}"
      mv "${filename}" "${newFilename}"
    else
      echo "cp ${filename} ${newFilename}"
      cp "${filename}" "${newFilename}"
    fi
  done;
else
  echo "No files found matching pattern *${query}*"
fi