Split a file similar to how Total Commander does it (No CRC).

splitfile.go

package main

import (
	"fmt"
	"io"
	"os"
	"path/filepath"
)

const (
	each = 1073741824
)

func main() {
	f, err := os.Open("shared-finished.zpaq")
	if err != nil {
		panic(err)
	}
	at := 650
	f.Seek(int64((at-1)*each), os.SEEK_CUR)
	defer f.Close()
	for {
		name := fmt.Sprintf("e:\\up\\%d00-%d99\\shared-finished.%03d", at/100, at/100, at)
		err = os.MkdirAll(filepath.Dir(name), 0666)
		if err != nil {
			panic(err)
		}
		out, err := os.Create(name)
		if err != nil {
			panic(err)
		}
		n, err := io.CopyN(out, f, each)
		if err != nil && err != io.EOF {
			panic(err)
		}
		out.Close()
		if err == io.EOF {
			break
		}
		if n != each {
			panic("short copy")
		}
		fmt.Println("Copied segment", at)
		at++
	}
}