parcongo.go

package main

import (
    "fmt"
    "io/ioutil"
    "math/rand"
    "os"
    "strings"
    "sync"
)

func main() {
    input := ""
    output := ""

    osArgsLength := len(os.Args)

    if osArgsLength > 1 && osArgsLength == 3 {
        input = os.Args[1]
        output = os.Args[2]
    } else {
        fmt.Println("Please give input file as first arg and output file as second arg")

        return
    }

    fileBytes, err := ioutil.ReadFile(input)
    if err != nil {
        fmt.Print(err)
    }

    str := string(fileBytes)

    strLength := len(str)

    var result []string

    var mutex = &sync.Mutex{}
    var wg sync.WaitGroup

    wg.Add(strLength)

    for i := 0; i < strLength; i++ {
        go func(i int) {
            defer wg.Done()
            char := str[i]

            random := rand.Intn(1000)

            mutex.Lock()

            obf := string(fmt.Sprintf("%v%v", string(char), random))

            result = append(result, obf)

            mutex.Unlock()
        }(i)
    }

    wg.Wait()

    resultStr := strings.Join(result, "")
    outputBytes := []byte(resultStr)

    err = ioutil.WriteFile(output, outputBytes, 0644)
    if err != nil {
        panic(err)
    }
}