batch_renamer

#!/usr/bin/groovy
def printErr = System.err.&println

if (args.length != 2) {
   printErr "Invalid number of arguments."
   printErr usage()
   System.exit(-1)
}

def source_dir = new File(args[0])
if (!source_dir.isDirectory()){
   printErr "${source_dir} is not a directory."
   printErr usage()
   System.exit(-1)
}

def renaming_list = new File(args[1])
if (!renaming_list.isFile()){
   printErr "${renaming_list} is not a file."
   printErr usage()
   System.exit(-1)
}

def contained_files = source_dir.listFiles()
contained_files = contained_files.sort()

lines = renaming_list.readLines()
lines = clean_lines(lines)

if (lines.size() != contained_files.size()) {
   printErr "The number of lines in the renaming list should be same as the number of files in the source directory"
   printErr "Number of files in source directory : ${contained_files.size()}"
   printErr "Number of lines in renaming list : ${lines.size()}"
   System.exit(-1)
}

println "After renaming the new files names would be :"

lines.size().times {
  println "${contained_files[it]} ==> ${lines[it]}"
}

def input = ""
System.in.withReader{
		println "Do you wish to continue? Enter 'yes' to continue. Anythin else will terminate execution"
		input = it.readLine()
}

if (input.equals('yes')){
   //continue renaming
   lines.size().times {
   	  contained_files[it].renameTo(lines[it])
   }
}else{
   return
}



def usage(){
	"Usage: batch_renamer source_dir new_name_file"
}

def clean_lines(lines) {
	def cleanedLines = []
	lines.each{
		if (it.trim().equals("")){
		}else{
			cleanedLines << it
		}
	}
	cleanedLines
}