Class: Archive::Zip::ExtraField::Unix

Inherits:
Object
  • Object
show all
Defined in:
lib/archive/zip/extra_field/unix.rb

Overview

Archive::Zip::Entry::ExtraField::Unix represents an extra field which contains the last modified time, last accessed time, user name, and group name for a ZIP archive entry. Times are in Unix time format (seconds since the epoc).

This class also optionally stores either major and minor numbers for devices or a link target for either hard or soft links. Which is in use when given and instance of this class depends upon the external file attributes for the ZIP archive entry associated with this extra field.

Constant Summary collapse

ID =

The identifier reserved for this extra field type.

0x000d

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(mtime, atime, uid, gid, data = '') ⇒ Unix

Creates a new instance of this class. mtime and atime should be Time instances. uid and gid should be user and group IDs as Integers respectively. data should be a string containing either major and minor device numbers consecutively packed as little endian, 4-byte, unsigned integers (see the V directive of Array#pack) or a path to use as a link target.



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# File 'lib/archive/zip/extra_field/unix.rb', line 46

def initialize(mtime, atime, uid, gid, data = '')
  @header_id = ID
  @mtime = mtime
  @atime = atime
  @uid = uid
  @gid = gid
  @data = data
end

Instance Attribute Details

#atime ⇒ Object

A Time object representing the last accessed time for an entry.



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# File 'lib/archive/zip/extra_field/unix.rb', line 58

def atime
  @atime
end

#data ⇒ Object (readonly, protected)

Returns the value of attribute data.



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# File 'lib/archive/zip/extra_field/unix.rb', line 138

def data
  @data
end

#gid ⇒ Object

An integer representing the group ownership for an entry.



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# File 'lib/archive/zip/extra_field/unix.rb', line 64

def gid
  @gid
end

#header_id ⇒ Object (readonly)

Returns the header ID for this ExtraField.



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# File 'lib/archive/zip/extra_field/unix.rb', line 56

def header_id
  @header_id
end

#mtime ⇒ Object

A Time object representing the last modified time for an entry.



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# File 'lib/archive/zip/extra_field/unix.rb', line 60

def mtime
  @mtime
end

#uid ⇒ Object

An integer representing the user ownership for an entry.



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# File 'lib/archive/zip/extra_field/unix.rb', line 62

def uid
  @uid
end

Class Method Details

.parse_central(data) ⇒ Object Also known as: parse_local

This method signature is part of the interface contract expected by Archive::Zip::Entry for extra field objects.

Parses data which is expected to be a String formatted according to the official ZIP specification.

Raises Archive::Zip::ExtraFieldError if data contains invalid data.



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# File 'lib/archive/zip/extra_field/unix.rb', line 30

def parse_central(data)
  unless data.length >= 12 then
    raise Zip::ExtraFieldError, "invalid size for Unix data: #{data.size}"
  end
  atime, mtime, uid, gid, rest = data.unpack('VVvva')
  new(Time.at(mtime), Time.at(atime), uid, gid, rest)
end

Instance Method Details

#device_numbers ⇒ Object

Attempts to return a two element array representing the major and minor device numbers which may be stored in the variable data section of this object.



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# File 'lib/archive/zip/extra_field/unix.rb', line 69

def device_numbers
  @data.unpack('VV')
end

#device_numbers=(major_minor) ⇒ Object

Takes a two element array containing major and minor device numbers and stores the numbers into the variable data section of this object.



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# File 'lib/archive/zip/extra_field/unix.rb', line 75

def device_numbers=(major_minor)
  @data = major_minor.pack('VV')
end

#dump_local ⇒ Object Also known as: dump_central

This method signature is part of the interface contract expected by Archive::Zip::Entry for extra field objects.

Returns a String suitable to writing to a local file record in a ZIP archive file which contains the data for this object.



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# File 'lib/archive/zip/extra_field/unix.rb', line 118

def dump_local
  [
    ID,
    12 + @data.size,
    @atime.to_i,
    @mtime.to_i,
    @uid,
    @gid
  ].pack('vvVVvv') + @data
end

#link_target ⇒ Object

Attempts to return a string representing the path of a file which is either a symlink or hard link target which may be stored in the variable data section of this object.



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# File 'lib/archive/zip/extra_field/unix.rb', line 82

def link_target
  @data
end

#link_target=(link_target) ⇒ Object

Takes a string containing the path to a file which is either a symlink or a hardlink target and stores it in the variable data section of this object.



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# File 'lib/archive/zip/extra_field/unix.rb', line 89

def link_target=(link_target)
  @data = link_target
end

#merge(other) ⇒ Object

This method signature is part of the interface contract expected by Archive::Zip::Entry for extra field objects.

Merges the attributes of other into this object and returns self.

Raises ArgumentError if other is not the same class as this object.



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# File 'lib/archive/zip/extra_field/unix.rb', line 99

def merge(other)
  if self.class != other.class then
    raise ArgumentError, "#{self.class} is not the same as #{other.class}"
  end

  @atime = other.atime
  @mtime = other.mtime
  @uid = other.uid
  @gid = other.gid
  @data = other.data

  self
end