Searches for files in a directory hierarchy matching a given pattern

FileSearch.scala

import scala.xml._
import scala.xml.transform._
import java.io.File
import scala.util.matching.Regex
import scala.util.matching.Regex.Match
/**
Creator: 2013, Olivier Huin (https://github.com/olih)
License: Eclipse Public License - v 1.0
Contributors:
*/
object FileSearch {

     object Meta {
     val description = "Searches for files in a directory hierarchy matching a given pattern"
     val signature = "FileSearch.process(idirectory: String, filterRegex: scala.util.matching.Regex)"
     val parameters = Array(
      "idirectory: the directory to start the search from.",
      "filterRegex: a pattern which needs to be found in the files to be processed")
     val creator = "Olivier Huin (https://github.com/olih)"
     val license = "Eclipse Public License - v 1.0"
     val copyrightYear = 2013
     val keywords="file"
     val version="1.15"
     val usage = s"""
     Usage: $signature
      
     $description
     * ${parameters(0)}
     * ${parameters(1)}
     
     Creator: $copyrightYear, $creator
     License: $license
     Keywords: $keywords
     Version: $version
     """
    }
 
   def process(idirectory: String, filterRegex: scala.util.matching.Regex): Array[File] = {
    require(idirectory!=null, {println("You must provide a directory to search from !")})
    require(filterRegex!=null, {println("You must provide a regular expression for searching !")})
    val inputDir = new File(idirectory)
    require(inputDir.exists(),{println(s"The given directory does not exist! $inputDir \n")})
    require(inputDir.isDirectory(),{println(s"The parameter is not a directory ! $inputDir \n")})
    
    val allfiles = recursiveListFiles(inputDir)
    
    val r = allfiles.filter(f => filterRegex.pattern.matcher(f.getName).find && f.isFile)
    return r
  }

    def recursiveListFiles(f: File): Array[File] = {
      val these = f.listFiles
      these ++ these.filter(_.isDirectory).flatMap(recursiveListFiles)
  }

}