create-a-file-on-magnetic-tape.go

package main

import (
	"archive/tar"
	"compress/gzip"
	"flag"
	"io"
	"log"
	"os"
	"time"
)

func main() {
	filename := flag.String("file", "TAPE.FILE", "filename within TAR")
	data := flag.String("data", "", "data for file")
	outfile := flag.String("out", "", "output file or device (e.g. /dev/tape)")
	gzipFlag := flag.Bool("gzip", false, "use gzip compression")
	flag.Parse()

	var w io.Writer = os.Stdout
	if *outfile != "" {
		f, err := os.Create(*outfile)
		if err != nil {
			log.Fatalf("opening/creating %q: %v", *outfile, err)
		}
		defer f.Close()
		w = f
	}

	if *gzipFlag {
		zw := gzip.NewWriter(w)
		defer zw.Close()
		w = zw
	}

	tw := tar.NewWriter(w)
	defer tw.Close()
	w = tw
	tw.WriteHeader(&tar.Header{
		Name:     *filename,
		Mode:     0660,
		Size:     int64(len(*data)),
		ModTime:  time.Now(),
		Typeflag: tar.TypeReg,
		Uname:    "guest",
		Gname:    "guest",
	})

	_, err := w.Write([]byte(*data))
	if err != nil {
		log.Fatal("writing data:", err)
	}
}

//\Create-a-file-on-magnetic-tape\create-a-file-on-magnetic-tape.go