Encodes standard input by base64. Vice versa.

base64.rb

#!/usr/bin/ruby

require 'optparse'
require 'base64'

option_hash = {}
OptionParser.new{|opt|
	opt.on('-e [VAL]') {|v| option_hash[:e] = v}
	opt.on('-d VAL')   {|v| option_hash[:d] = v}

	begin
		# Argument shift
		opt.parse!(ARGV)
	rescue
		puts "Invalid option."
		exit 1
	end 
}

def usage
	puts "Usage: base64 [-e <filename>] [-d filename] [-h]"
	puts "Help:  This script encodes file or standard input using Base64."
	puts "       Moreover, it decodes file that was encoded in Base64."
	puts "Option:"
	puts "-e     Encode as Base64. It supports argument and standard input."
	puts "-d     Decode as Base64. Only argument."
	puts "-h     Help."
	puts ""
end


def encode64(recieve)
	if File.pipe?(STDIN) || File.select([STDIN], [], [], 0) != nil then
		STDIN.read.each_line do |line|
			puts Base64.encode64(line)
		end
	else
		if recieve != nil then
			# Case: No STDIN and Is recieve
			file = File.expand_path(recieve)

			if File.exist?(file) then
				# Case: File exists
				contents = File.open(file).read
				puts Base64.encode64(contents)
			else
				# Use argument as is for Base64
				puts Base64.encode64(recieve)
			end
		else
			usage
			exit 1
		end
	end
end

def decode64(recieve)
	file = File.expand_path(recieve)

	if File.exist?(file) then
		contents = File.open(file).read
		puts Base64.decode64(contents)
	else
		puts File.basename(file) + ": No such file or directory"
	end

end

if option_hash.size <= 0 then
	# Case: No argument
	usage
	exit 1
end

if option_hash.key?(:e) then
	# Call sub
	encode64(option_hash[:e])
elsif option_hash.key?(:d) then
	# Call sub
	decode64(option_hash[:d])
end