Class: Gem::Package::TarHeader
- Defined in:
- lib/rubygems/package/tar_header.rb
Overview
– 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
Constant Summary collapse
- FIELDS =
Fields in the tar header
[ :checksum, :devmajor, :devminor, :gid, :gname, :linkname, :magic, :mode, :mtime, :name, :prefix, :size, :typeflag, :uid, :uname, :version, ].freeze
- PACK_FORMAT =
Pack format for a tar header
'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'
- UNPACK_FORMAT =
Unpack format for a tar header
'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'
- EMPTY_HEADER =
:nodoc:
("\0" * 512).freeze
Class Method Summary collapse
-
.from(stream) ⇒ Object
Creates a tar header from IO
stream
. - .oct_or_256based(str) ⇒ Object
- .strict_oct(str) ⇒ Object
Instance Method Summary collapse
-
#==(other) ⇒ Object
:nodoc:.
-
#empty? ⇒ Boolean
Is the tar entry empty?.
-
#initialize(vals) ⇒ TarHeader
constructor
Creates a new TarHeader using
vals
. -
#to_s ⇒ Object
:nodoc:.
-
#update_checksum ⇒ Object
Updates the TarHeader’s checksum.
Constructor Details
#initialize(vals) ⇒ TarHeader
Creates a new TarHeader using vals
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# File 'lib/rubygems/package/tar_header.rb', line 144 def initialize(vals) unless vals[:name] && vals[:size] && vals[:prefix] && vals[:mode] raise ArgumentError, ":name, :size, :prefix and :mode required" end vals[:uid] ||= 0 vals[:gid] ||= 0 vals[:mtime] ||= 0 vals[:checksum] ||= "" vals[:typeflag] = "0" if vals[:typeflag].nil? || vals[:typeflag].empty? vals[:magic] ||= "ustar" vals[:version] ||= "00" vals[:uname] ||= "wheel" vals[:gname] ||= "wheel" vals[:devmajor] ||= 0 vals[:devminor] ||= 0 FIELDS.each do |name| instance_variable_set "@#{name}", vals[name] end @empty = vals[:empty] end |
Class Method Details
.from(stream) ⇒ Object
Creates a tar header from IO stream
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# File 'lib/rubygems/package/tar_header.rb', line 100 def self.from(stream) header = stream.read 512 empty = (EMPTY_HEADER == 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 => empty end |
.oct_or_256based(str) ⇒ Object
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# File 'lib/rubygems/package/tar_header.rb', line 132 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.unpack('N2').last if str =~ /\A[\x80\xff]/n strict_oct(str) end |
.strict_oct(str) ⇒ Object
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# File 'lib/rubygems/package/tar_header.rb', line 126 def self.strict_oct(str) return str.strip.oct if str.strip =~ /\A[0-7]*\z/ raise ArgumentError, "#{str.inspect} is not an octal string" end |
Instance Method Details
#==(other) ⇒ Object
:nodoc:
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# File 'lib/rubygems/package/tar_header.rb', line 175 def ==(other) # :nodoc: self.class === other and @checksum == other.checksum and @devmajor == other.devmajor and @devminor == other.devminor and @gid == other.gid and @gname == other.gname and @linkname == other.linkname and @magic == other.magic and @mode == other.mode and @mtime == other.mtime and @name == other.name and @prefix == other.prefix and @size == other.size and @typeflag == other.typeflag and @uid == other.uid and @uname == other.uname and @version == other.version end |
#empty? ⇒ Boolean
Is the tar entry empty?
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# File 'lib/rubygems/package/tar_header.rb', line 171 def empty? @empty end |
#to_s ⇒ Object
:nodoc:
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# File 'lib/rubygems/package/tar_header.rb', line 195 def to_s # :nodoc: update_checksum header end |
#update_checksum ⇒ Object
Updates the TarHeader’s checksum
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# File 'lib/rubygems/package/tar_header.rb', line 203 def update_checksum header = header " " * 8 @checksum = oct calculate_checksum(header), 6 end |