Trivial dircmp in Golang - [Continue to enhance..]

dircmp.go

package main

import (
        "path/filepath"
        "os"
        "flag"
        "fmt"
)

type fileattr struct {
        fileinfo os.FileInfo
        path string
}

var left_list []fileattr
var right_list []fileattr

func Append(slice []fileattr, data fileattr) []fileattr {
        l := len(slice)
        if data.path != "" {
                newSlice := make([]fileattr, l+1)
                copy(newSlice, slice)
                slice = newSlice
                slice[l] = data

        }
        return slice
}

func left_visit(path string, f os.FileInfo, _ error) error {
        var attr fileattr

        attr.path = path
        attr.fileinfo = f

        left_list = Append(left_list, attr)
        return nil
}

func right_visit(path string, f os.FileInfo, _ error) error {
        var attr fileattr

        attr.path = path
        attr.fileinfo = f

        right_list = Append(right_list, attr)
        return nil
}

func cmp(dir1 string, dir2 string, list1 []fileattr, list2 []fileattr) {
        // Very trivial check for dircmp - still needs more enhancements
        if (len(list1) > len(list2)) {
                fmt.Printf("Directory: %s supersedes in total files %d over Directory: %s\n", dir1, (len(list1) - len(list2)), dir2)
        } else {
                fmt.Printf("Directory %s supersedes in total files %d over Directory: %s\n", dir2, (len(list2) - len(list1)), dir1)
        }
        //
        //
}

func main() {
        flag.Parse()
        left_dir := flag.Arg(0)
        right_dir := flag.Arg(1)

        if flag.NArg() < 2 {
                fmt.Printf("Please provide arguments in this fashion <master> <slave>\n")
                os.Exit(255)
        } else if flag.NArg() == 2 {
                filepath.Walk(left_dir, left_visit)
                filepath.Walk(right_dir, right_visit)
        }

        cmp(left_dir, right_dir, left_list, right_list)
}