base64 编码解码

import os
import base64
import streams

proc printHelp =
echo "genbase64 encode file into BASE64 text."
echo "usage: genbase64 input-file output-file"

proc encodeFile(inputFile: string, outputFile: string) =
let r = streams.newFileStream(inputFile, fmRead)
let w = streams.newFileStream(outputFile, fmWrite)
let data = r.readAll()
let base64text = base64.encode(data)

w.write(base64text)
w.flush()
w.close()
r.close()

let argv = commandLineParams()

if argv.len != 2:
printHelp()
else:
let inputFile = argv[0]
let outputFile = argv[1]
encodeFile(inputFile, outputFile)