A simple golang server for serving a single file

server.go

package main

import (
        "io"
        "log"
        "net/http"
        "io/ioutil"
        "os"
)
func main() {
        // Set routing rules
        http.HandleFunc("/", home)

        //Use the default DefaultServeMux.
        err := http.ListenAndServe(":8080", nil)
        if err != nil {
                log.Fatal(err)
        }
}

func home(w http.ResponseWriter, r *http.Request) {
        programName := os.Args[1]
        io.WriteString(w, readFile(programName))
}

func readFile(fileName string) string {
        data, err := ioutil.ReadFile(fileName)
        if err != nil {
                return "Error 404, File not Found!"
	}
        return string(data)
}