Automatically encode/decode base64 data via a STDIN pipe

base64_pipe.go

package main

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

func main() {
	f, _ := os.Stdin.Stat()
	if f.Mode()&os.ModeNamedPipe == 0 {
		fmt.Println("must pipe data into this command!")
		os.Exit(1)
	}
	scanner := bufio.NewScanner(os.Stdin)
	for scanner.Scan() {
		if scanner.Err() != nil {
			os.Exit(0)
		}
		decodedString, err := base64.StdEncoding.DecodeString(scanner.Text())
		if err != nil {
			data := []byte(scanner.Text())
			encodedString := base64.StdEncoding.EncodeToString(data)
			fmt.Println(encodedString)
			continue
		} else {
			fmt.Println(string(decodedString))
		}
	}
}

// echo -e 'Hello\nWorld!' > file.txt
// cat file.txt | ./base64
// cat file.txt | ./base64 | ./base64