Groovy Script to rename all TXT files in a directory

#!/usr/bin/env groovy
// Script to rename files that end in .txt replacing the XX to YY in the name

dirName = "/tmp"
new File(dirName).eachFile() { file ->
    if ( file.getName() =~ /.txt/ ) {
            def newName = (file.getName()).replaceFirst("XX", "YY")
            File f = new File(dirName + "/" + newName)
            file.renameTo(f)
            println file.getName() + " -> " + f.getName()
    } else {
            print "Skipping file " << file.getName() << "\n"
    }
}