replace the domain in the m3u8 files

m3u8_domain_replace.go

package main

import (
	"bufio"
	"flag"
	"fmt"
	"os"
	"path/filepath"
	"strings"
)

func main() {
	var fromDomain string
	var toDomain string
	var inputDir string
	var outputDir string
	var suffix string
	flag.StringVar(&fromDomain, "from", "", "from domain")
	flag.StringVar(&toDomain, "to", "", "to domain")
	flag.StringVar(&inputDir, "in", "", "input dir")
	flag.StringVar(&outputDir, "out", "", "output dir")
	flag.StringVar(&suffix, "suffix", "", "file name suffix")
	flag.Parse()

	if fromDomain == "" {
		fmt.Println("no from domain specified")
		return
	}
	if toDomain == "" {
		fmt.Println("no to domain specified")
		return
	}
	if inputDir == "" {
		fmt.Println("no input dir specified")
		return
	}
	if outputDir == "" {
		fmt.Println("no output dir specified")
		return
	}

	err := replace(fromDomain, toDomain, inputDir, outputDir, suffix)
	if err != nil {
		fmt.Println(err)
	}
}

func replace(fromDomain, toDomain, inputDir, outputDir, suffix string) error {
	err := filepath.Walk(inputDir, func(path string, fi os.FileInfo, err error) (retErr error) {
		if !fi.IsDir() {
			if suffix != "" && !strings.HasSuffix(path, suffix) {
				return
			}
			fInput, openErr := os.Open(path)
			if openErr != nil {
				retErr = openErr
				return
			}
			defer fInput.Close()

			fInputDir, pErr1 := filepath.Abs(inputDir)
			if pErr1 != nil {
				retErr = pErr1
				return
			}
			fOutputDir, pErr2 := filepath.Abs(outputDir)
			if pErr2 != nil {
				retErr = pErr2
				return
			}

			fOutputPath := strings.Replace(path, fInputDir, fOutputDir, -1)

			fOutputRelPath := filepath.Dir(fOutputPath)

			retErr = os.MkdirAll(fOutputRelPath, 0755)
			if retErr != nil {
				return
			}

			fOutput, openErr2 := os.OpenFile(fOutputPath, os.O_CREATE|os.O_WRONLY, 0666)
			if openErr2 != nil {
				retErr = openErr2
				return
			}
			defer fOutput.Close()

			fInputReader := bufio.NewScanner(fInput)
			fInputReader.Split(bufio.ScanLines)
			for fInputReader.Scan() {
				line := fInputReader.Text()

				if strings.Contains(line, fromDomain) {
					line = strings.Replace(line, fromDomain, toDomain, -1)
				}

				_, wErr := fOutput.WriteString(fmt.Sprintln(line))
				if wErr != nil {
					retErr = wErr
					return
				}
			}
		}
		return
	})

	return err
}