golang code challenge

gistfile1.txt

package main

import (
    "bufio"
    "fmt"
    "log"
    "os"
    "regexp"
    "strings"
)

func main() {
    file, err := os.Open("test.txt")

    if err != nil {
        log.Fatalf("failed opening file: %s", err)
    }

    lineFilter := regexp.MustCompile(`^[0-9\n\s]+$`)
    lineScanner := bufio.NewScanner(file)
    lineScanner.Split(bufio.ScanLines)
    caseNumber := 0

    for lineScanner.Scan() {
	    if lineFilter.MatchString(lineScanner.Text()) {
		continue
	    }
	    matched := lineScanner.Text()
	    words := strings.Split(matched, " ")
	    //fmt.Printf("%v\n", words)
	    len := len(words)
	    for i := 0; i<len/2 ; i++ {
	        tmp := words[len-i-1]
	        //words[len-i-1] = words[i]
		words[len-i-1], words[i] = words[i], words[len-i-1]
		words[i] = tmp
		}
	    matched = strings.Join(words," ")
	    caseNumber = caseNumber + 1
            fmt.Println("CASE#",caseNumber, matched)
    }
    file.Close()
}