# -*- ruby encoding: utf-8 -*-

require 'fileutils'

require 'minitar'

gem 'minitest'

require 'minitest/autorun'

module TarTester

private

def assert_headers_equal(h1, h2)

fields = %w(name 100 mode 8 uid 8 gid 8 size 12 mtime 12 checksum 8

typeflag 1 linkname 100 magic 6 version 2 uname 32 gname 32

devmajor 8 devminor 8 prefix 155)

offset = 0

until fields.empty?

name = fields.shift

length = fields.shift.to_i

if name == "checksum"

chksum_off = offset

offset += length

next

end

assert_equal(h1[offset, length], h2[offset, length],

"Field #{name} of the tar header differs.")

offset += length

end

assert_equal(h1[chksum_off, 8], h2[chksum_off, 8], "Checksumes differ.")

end

def assert_modes_equal(expected, actual, name)

unless Minitar.windows?

expected = "%04o" % (expected & 0777)

actual = "%04o" % (actual & 0777)

assert_equal(expected, actual, "Mode for #{name} does not match")

end

end

def tar_file_header(fname, dname, mode, length)

h = header("0", fname, dname, length, mode)

checksum = calc_checksum(h)

header("0", fname, dname, length, mode, checksum)

end

def tar_dir_header(name, prefix, mode)

h = header("5", name, prefix, 0, mode)

checksum = calc_checksum(h)

header("5", name, prefix, 0, mode, checksum)

end

def header(type, fname, dname, length, mode, checksum = nil)

checksum ||= " " * 8

arr = [ASCIIZ(fname, 100), Z(to_oct(mode, 7)), Z(to_oct(nil, 7)),

Z(to_oct(nil, 7)), Z(to_oct(length, 11)), Z(to_oct(0, 11)),

checksum, type, "\0" * 100, "ustar\0", "00", ASCIIZ("", 32),

ASCIIZ("", 32), Z(to_oct(nil, 7)), Z(to_oct(nil, 7)),

ASCIIZ(dname, 155) ]

arr = arr.join.bytes.to_a

h = arr.pack("C100C8C8C8C12C12C8CC100C6C2C32C32C8C8C155")

ret = h + "\0" * (512 - h.size)

assert_equal(512, ret.size)

ret

end

def calc_checksum(header)

sum = header.unpack("C*").inject { |s, a| s + a }

SP(Z(to_oct(sum, 6)))

end

def to_oct(n, pad_size)

if n.nil?

"\0" * pad_size

else

"%0#{pad_size}o" % n

end

end

def ASCIIZ(str, length)

str + "\0" * (length - str.length)

end

def SP(s)

s + " "

end

def Z(s)

s + "\0"

end

def SP_Z(s)

s + " \0"

end

end