web server example for serving static file

http.go

package main

import (
    "http"
    "runtime"
    "log"
    "flag"
    "os"
)

var (
    path   = flag.String("root", "/var/www/", "`-root='/var/www/'`. Set root directory, use absolute path.")
    stat   = flag.Bool("stat", false, "`-stat=true` or `-stat=false`. Show memory stats to stdout.")
    help   = flag.Bool("help", false, "`-help`. Show this message.")
)

func memStat(label string) {
    log.Printf("\nMem Stat %s:\nheapAlloc: %d | footprint: %d\n\n",
               label, runtime.MemStats.HeapAlloc, runtime.MemStats.Sys)
}

func handler(w http.ResponseWriter, r *http.Request) {
    fname := "index.html"
    if len(r.URL.Path) > 1 {
        fname = r.URL.Path[1:]
    }
    ff := *path + fname
    http.ServeFile(w, r, ff)
    if *stat {
        go memStat(fname)
    }
    w = nil
    go runtime.GC()
}

func main() {
    flag.Parse()
    if *help {
        flag.Usage()
        os.Exit(0)
    }
    http.HandleFunc("/", handler)
    http.ListenAndServe(":5050", nil)
}