A simple Scala script to group files by month.

FileSorter.scala

import java.nio.file._
import java.nio.file.attribute._
import scala.collection.JavaConverters._
import java.time._
import java.time.format._

val fmt = DateTimeFormatter.ofPattern("yyyy-MM")
val src = Paths.get(args(0))
val dst = Paths.get(args(1))

println( s"reading from: ${src.toAbsolutePath}")
println( s"writing to: ${dst.toAbsolutePath}")

println("Creating destination")
Files.createDirectory(dst)
println("...done")

def creationMonthOf( p:Path ):String = {
    val attr = Files.readAttributes(p, classOf[BasicFileAttributes])
    val createdAt = Instant.ofEpochMilli(attr.creationTime.toMillis).atZone(ZoneId.of("UTC"))
    fmt.format(createdAt);
}

def moveFiles( monthStr:String, paths:Seq[Path]):Unit = {
    val monthDir = dst.resolve(monthStr)
    Files.createDirectory(monthDir)
    paths.foreach( p => Files.move(p, monthDir.resolve(p.getFileName)) )
}

val groups = Files.list(src).iterator.asScala.toSeq.groupBy( creationMonthOf );
groups.keys.toSeq.sorted.foreach( k=> {
    print(s"$k ${groups(k).length}...") 
    moveFiles(k, groups(k))
    println("✅")
})