Writes an output file of desired size ( flags check pending)

writefiletosize.go

package main

import(
	"io"
	"os"
	"fmt"
	"flag"
)
var size = flag.Int64("size", 1024, "Size of the file to create")
var oName = flag.String("filename", "C:\\output.txt", "Name of the file to create")

func usage(){
    fmt.Fprintf(os.Stderr, "usage: %s [size]  [filename]\n" , os.Args[0])
    flag.PrintDefaults()
    os.Exit(2)
}

func main() {

    flag.Usage = usage
   	flag.Parse()
   	fmt.Println("length", len(flag.Args()));

	//read from file
	fi, err := os.Open("D:\\work\\cleanup.sql")
    if err != nil { panic(err) }
    defer fi.Close()

	fo, err := os.Create(*oName)
	if err != nil { panic(err) }
	defer fo.Close()

	buf := make([]byte, 4096)

	n, err := fi.Read(buf)
    if err != nil && err != io.EOF { panic(err) }
    //if n == 0 { panic() }

	for {

		if n2, err := fo.Write(buf[:n]); err != nil {
	            panic(err)
	    }else if n2 != 0{
	    	info, err2 := os.Stat(*oName)
	    	 if(err2 != nil) {
	    	 	panic(err2)
	    	 }
	    	
	    	if info.Size() >= *size {
	    		fmt.Printf(" breaking ") 
	    		break;
	    	}
	    }
	}
}