AlkantarClanX12
Your IP : 3.142.156.58
# frozen_string_literal: true
# rubocop:disable Style/AsciiComments
# Copyright (C) 2004 Mauricio Julio Fernández Pradier
# See LICENSE.txt for additional licensing information.
# rubocop:enable Style/AsciiComments
##
#--
# struct tarfile_entry_posix {
# char name[100]; # ASCII + (Z unless filled)
# char mode[8]; # 0 padded, octal, null
# char uid[8]; # ditto
# char gid[8]; # ditto
# char size[12]; # 0 padded, octal, null
# char mtime[12]; # 0 padded, octal, null
# char checksum[8]; # 0 padded, octal, null, space
# char typeflag[1]; # file: "0" dir: "5"
# char linkname[100]; # ASCII + (Z unless filled)
# char magic[6]; # "ustar\0"
# char version[2]; # "00"
# char uname[32]; # ASCIIZ
# char gname[32]; # ASCIIZ
# char devmajor[8]; # 0 padded, octal, null
# char devminor[8]; # o padded, octal, null
# char prefix[155]; # ASCII + (Z unless filled)
# };
#++
# A header for a tar file
class Gem::Package::TarHeader
##
# Fields in the tar header
FIELDS = [
:checksum,
:devmajor,
:devminor,
:gid,
:gname,
:linkname,
:magic,
:mode,
:mtime,
:name,
:prefix,
:size,
:typeflag,
:uid,
:uname,
:version,
].freeze
##
# Pack format for a tar header
PACK_FORMAT = "a100" + # name
"a8" + # mode
"a8" + # uid
"a8" + # gid
"a12" + # size
"a12" + # mtime
"a7a" + # chksum
"a" + # typeflag
"a100" + # linkname
"a6" + # magic
"a2" + # version
"a32" + # uname
"a32" + # gname
"a8" + # devmajor
"a8" + # devminor
"a155" # prefix
##
# Unpack format for a tar header
UNPACK_FORMAT = "A100" + # name
"A8" + # mode
"A8" + # uid
"A8" + # gid
"A12" + # size
"A12" + # mtime
"A8" + # checksum
"A" + # typeflag
"A100" + # linkname
"A6" + # magic
"A2" + # version
"A32" + # uname
"A32" + # gname
"A8" + # devmajor
"A8" + # devminor
"A155" # prefix
attr_reader(*FIELDS)
EMPTY_HEADER = ("\0" * 512).b.freeze # :nodoc:
##
# Creates a tar header from IO +stream+
def self.from(stream)
header = stream.read 512
return EMPTY if header == EMPTY_HEADER
fields = header.unpack UNPACK_FORMAT
new name: fields.shift,
mode: strict_oct(fields.shift),
uid: oct_or_256based(fields.shift),
gid: oct_or_256based(fields.shift),
size: strict_oct(fields.shift),
mtime: strict_oct(fields.shift),
checksum: strict_oct(fields.shift),
typeflag: fields.shift,
linkname: fields.shift,
magic: fields.shift,
version: strict_oct(fields.shift),
uname: fields.shift,
gname: fields.shift,
devmajor: strict_oct(fields.shift),
devminor: strict_oct(fields.shift),
prefix: fields.shift,
empty: false
end
def self.strict_oct(str)
str.strip!
return str.oct if /\A[0-7]*\z/.match?(str)
raise ArgumentError, "#{str.inspect} is not an octal string"
end
def self.oct_or_256based(str)
# \x80 flags a positive 256-based number
# \ff flags a negative 256-based number
# In case we have a match, parse it as a signed binary value
# in big-endian order, except that the high-order bit is ignored.
return str.unpack1("@4N") if /\A[\x80\xff]/n.match?(str)
strict_oct(str)
end
##
# Creates a new TarHeader using +vals+
def initialize(vals)
unless vals[:name] && vals[:size] && vals[:prefix] && vals[:mode]
raise ArgumentError, ":name, :size, :prefix and :mode required"
end
@checksum = vals[:checksum] || ""
@devmajor = vals[:devmajor] || 0
@devminor = vals[:devminor] || 0
@gid = vals[:gid] || 0
@gname = vals[:gname] || "wheel"
@linkname = vals[:linkname]
@magic = vals[:magic] || "ustar"
@mode = vals[:mode]
@mtime = vals[:mtime] || 0
@name = vals[:name]
@prefix = vals[:prefix]
@size = vals[:size]
@typeflag = vals[:typeflag]
@typeflag = "0" if @typeflag.nil? || @typeflag.empty?
@uid = vals[:uid] || 0
@uname = vals[:uname] || "wheel"
@version = vals[:version] || "00"
@empty = vals[:empty]
end
EMPTY = new({ # :nodoc:
checksum: 0,
gname: "",
linkname: "",
magic: "",
mode: 0,
name: "",
prefix: "",
size: 0,
uname: "",
version: 0,
empty: true,
}).freeze
private_constant :EMPTY
##
# Is the tar entry empty?
def empty?
@empty
end
def ==(other) # :nodoc:
self.class === other &&
@checksum == other.checksum &&
@devmajor == other.devmajor &&
@devminor == other.devminor &&
@gid == other.gid &&
@gname == other.gname &&
@linkname == other.linkname &&
@magic == other.magic &&
@mode == other.mode &&
@mtime == other.mtime &&
@name == other.name &&
@prefix == other.prefix &&
@size == other.size &&
@typeflag == other.typeflag &&
@uid == other.uid &&
@uname == other.uname &&
@version == other.version
end
def to_s # :nodoc:
update_checksum
header
end
##
# Updates the TarHeader's checksum
def update_checksum
header = header " " * 8
@checksum = oct calculate_checksum(header), 6
end
private
def calculate_checksum(header)
header.sum(0)
end
def header(checksum = @checksum)
header = [
name,
oct(mode, 7),
oct(uid, 7),
oct(gid, 7),
oct(size, 11),
oct(mtime, 11),
checksum,
" ",
typeflag,
linkname,
magic,
oct(version, 2),
uname,
gname,
oct(devmajor, 7),
oct(devminor, 7),
prefix,
]
header = header.pack PACK_FORMAT
header.ljust 512, "\0"
end
def oct(num, len)
format("%0#{len}o", num)
end
end