utils.go

package utils

import (
	"os"
	"io"
	"fmt"
	"bytes"
	"errors"
	"net/mail"
	"archive/tar"
	"path/filepath"
	"compress/gzip"
	"github.com/google/uuid"
)

func Print(a ...any) {
	os.Stdout.WriteString(fmt.Sprint(a ...))
}

func Println(a ...any) {
	Print(a...)
	Print("\n")
}

func PrintErr(a ...any) {
	os.Stderr.WriteString(fmt.Sprint(a ...))
}

func PrintlnErr(a ...any) {
	PrintErr(a...)
	PrintErr("\n")
}

// Returns true if the specified file exists, false otherwise.
func FileExists(filename string) bool {
	info, err := os.Stat(filename)
	if os.IsNotExist(err) {
	   return false
	}
	return !info.IsDir()
}

// Creates a tar.gz archive of dir and all its files and subdirectories.
// Source code slightly modified from: https://gist.github.com/mimoo/25fc9716e0f1353791f5908f94d6e726
func TarGzDir(dir, archive string) error {
	var buf bytes.Buffer

	gzWriter := gzip.NewWriter(&buf)
	tarWriter := tar.NewWriter(gzWriter)

	// Walks through every file in the directory
	filepath.Walk(dir, func(file string, fi os.FileInfo, err error) error {
		header, err := tar.FileInfoHeader(fi, file)
		if err != nil {
			return err
		}

		header.Name = filepath.ToSlash(file)

		if err := tarWriter.WriteHeader(header); err != nil {
			return err
		}
		// if not a dir, write file content
		if !fi.IsDir() {
			data, err := os.Open(file)
			if err != nil {
				return err
			}
			if _, err := io.Copy(tarWriter, data); err != nil {
				return err
			}
		}
		return nil
	})

	if err := tarWriter.Close(); err != nil {
		return err
	}
	if err := gzWriter.Close(); err != nil {
		return err
	}

	fileToWrite, err := os.OpenFile(archive, os.O_CREATE|os.O_RDWR, os.FileMode(0750))
	if err != nil {
		return err
	}
	if _, err := io.Copy(fileToWrite, &buf); err != nil {
		return err
	}

	return nil
}

func GetRandomTempFilename() (string, error) {
	tempDir := os.TempDir()
	uuid, err := uuid.NewRandom()
	if err != nil {
		return "", errors.New("Failed creating random UUID: "+err.Error())
	}
	randName := "temp_"+uuid.String()
	return filepath.Join(tempDir, randName), nil
}

func IsEmail(email string) bool {
    _, err := mail.ParseAddress(email)
	return err == nil
}