Functions that count lines in a file, then creates a new file sorted by those line counts.

linecount.scala

import scala.collection.mutable.{Map}
import scala.io.{Source}
import java.io.{File, PrintWriter}
import scala.util.{Sorting}

object linecount {
    
    def run(path:String) = {
    	var frequencies:Map[String, Int] = Map()
        for (line <- Source.fromFile(path).getLines) {
            var count = 1
            if (frequencies.contains(line)) {
            	count += frequencies.get(line).get
            }

            frequencies.put(line, count)
        }

        val sorted_keys = frequencies.keys.toStream.sortWith((a, b) => frequencies(a) < frequencies(b))

        var newpath = path + ".sorted"        
        var p = new PrintWriter(newpath)
        try {
	        sorted_keys.foreach(x => {
	        	var sentence = x
	    		p.println(frequencies.get(sentence).get + " " + sentence);
	    	})
        }
        catch {
  	      	case e:Exception => {
	        	println("Error writing file " + newpath)
	        }
        }
        finally {
        	try {
	        	p.close();
	        }
	        catch {
	  	      	case e:Exception => {}
	  	    }
        }
    } 

    def main(args: Array[String]) {
        if (args.length  < 1) {
        	println("A filename is required")
        	return
        }

        val path = args(0)
        if (path == null || path.isEmpty()) {
        	println("Please give a valid filename")
        }
    	run(path)
    }
}

linecount.sh

#!/bin/sh


count() {
    FILENAME=$1
    while read x; do 
        echo $(grep -caF "$x" $FILENAME) $x
    done < $FILENAME | sort -n | uniq> "$FILENAME".sorted
}

count $1