url 安全的 base64 编码解码

ubase64.go

package main

import (
	"bufio"
	"encoding/base64"
	"flag"
	"fmt"
	"log"
	"os"
)

var (
	decodeTag  = flag.Bool("d", false, "decode")
	urlSafeTag = flag.Bool("u", false, "urlsafe")
)

func base64Encode(src []byte) string {
	if *urlSafeTag {
		return base64.URLEncoding.EncodeToString(src)
	} else {
		return base64.StdEncoding.EncodeToString(src)
	}
}

func base64Decode(src string) ([]byte, error) {
	if *urlSafeTag {
		return base64.URLEncoding.DecodeString(src)
	} else {
		return base64.StdEncoding.DecodeString(src)
	}
}

func do(str string) {
	if *decodeTag {
		after, err := base64Decode(str)
		if err != nil {
			log.Println(str, "\t", "Error:", err)
			return
		}
		fmt.Println(str, "\t", string(after))
	} else {
		after := base64Encode([]byte(str))
		fmt.Println(str, "\t", after)
	}
}

var usage string = `
ubase64 - url safe base64 encode/decode data and print to standard output
usage:
    ubase64 [-d] [-u] string
    -d      decode
    -u      url safe
    -       read from stdin
default:
    encode and not url safe
`

func main() {
	flag.Parse()
	lenArgs := len(flag.Args())
	if lenArgs == 0 {
		fmt.Println(usage)
		return
	}
	if flag.Arg(0) == "-" {
		scanner := bufio.NewScanner(os.Stdin)
		for scanner.Scan() {
			do(scanner.Text())
		}
		if err := scanner.Err(); err != nil {
			log.Fatal(err)
		}
	} else {
		for i := 0; i < lenArgs; i++ {
			do(flag.Arg(i))
		}
	}
}