goroutine and messages

listFiles.go

package listfiles

import (
	"fmt"
	"os"
	"regexp"
	"strings"
	"sync"
)

type Errors struct {
	Message string
	Error   error
}

var wg sync.WaitGroup

func main() {
	var wg sync.WaitGroup
	var sliceFiles []string
	var chErr []string
	ch := make(chan Errors, 0)

	filesInDir, err := os.ReadDir("/Users/elulcao/")
	if err != nil {
		fmt.Println("No files in dir" + err.Error())
		return
	}

	for _, f := range filesInDir {
		fName := string(f.Name())

		re := regexp.MustCompile(`(.*).txt$`)
		match := re.MatchString(fName)
		if !match {
			continue
		}

		sliceFiles = append(sliceFiles, fName)
	}
	for _, f := range sliceFiles {
		fmt.Println("File: " + f)
		go listFilesWithExt(f, ch, &wg)
	}

	fmt.Println("Finished the process")

	for _ = range sliceFiles {
		c := <-ch
		if c.Error != nil {
			chErr = append(chErr, c.Error.Error())
		}
	}

	wg.Wait()

	for _, c := range chErr {
		fmt.Println(c)
	}
}

func listFilesWithExt(file string, ch chan Errors, wg *sync.WaitGroup) {
	wg.Add(1)
	defer wg.Done()

	if strings.Contains(file, "BadWord") {
		ch <- Errors{"NOK:", fmt.Errorf("File with BadWord " + file)}
		return
	}

	fmt.Println(file)
	ch <- Errors{"OK:", nil}

	return
}