Bash functions to find and replace across multiple files / rename multiple files

findAndReplace.sh

  ##----------------------------------------------------------------------------
  ##
  ##  functions to find and replace within multiple files or in file names
  ##
  ##----------------------------------------------------------------------------

  # if dir, return dir; if symlink, return dir that symlink points to
  function unsym(){
    echo "$(python -c "import os; print(os.path.realpath('"$1"'))")"
  }

  # the below three functions all use the following scheme:
  #   $1: where to look, ex: dir/*.txt
  #   $2: what to look for, ex: oldstring
  #   $3: what to replace it with, ex: new_string
  
  # example:
  #   $  findAndRename "foo/bar*.txt" _2017 _2018
  #   ... will replace any occurrences of "_2017" in the names of
  #       all *.txt files (whose names begin with "bar") in the foo/
  #       directory with "_2018"

  # find and replace across multiple files
  function findAndReplace(){
    mypath=$(unsym "$1")
    echo "Replacing '$2' with '$3' for these files: $mypath"
    echo "(Note: if you're using a glob in the path, put the first argument in quotes.)"
    perl -pi -w -e "s/$2/$3/g;" $mypath
  }

  # find files and rename them
  function findAndRename(){
    mypath=$(unsym "$1")
    echo "Replacing '$2' with '$3' in the names of these files: $mypath"
    echo "(Note: if you're using a glob in the path, put the first argument in quotes.)"
    for f in $mypath; do mv -- "$f" "${f//$2/$3}"; done
  }

  # change name of Java class for all files in a given directory
  function changeClassName(){
    findAndRename "$1" "$2" "$3"
    findAndReplace "$1" "$2" "$3"
  }