Class: Ips::BinaryReader

Inherits:
Object
  • Object
show all
Defined in:
lib/ips/binary_reader.rb

Overview

Binary data reader for parsing IPS patch files.

This class provides methods to read various data types from binary data, including strings, integers of different sizes, and raw bytes.

Examples:

Reading from binary data

data = File.binread("patch.ips")
reader = Ips::BinaryReader.new(data)
header = reader.read_string(5) # => "PATCH"

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(data) ⇒ BinaryReader

Creates a new BinaryReader instance.

Parameters:

  • data (String) —

    the binary data to read from



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# File 'lib/ips/binary_reader.rb', line 28

def initialize(data)
  @data = StringIO.new(data)
end

Instance Attribute Details

#data ⇒ StringIO (readonly)

Returns the internal StringIO object containing the binary data.

Returns:

  • (StringIO) —

    the internal StringIO object containing the binary data



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# File 'lib/ips/binary_reader.rb', line 22

def data
  @data
end

Instance Method Details

#go_back(n_bytes) ⇒ Integer

Moves the read position backwards by a specified number of bytes.

Parameters:

  • n_bytes (Integer) —

    the number of bytes to move back

Returns:

  • (Integer) —

    the new position in the stream



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# File 'lib/ips/binary_reader.rb', line 68

def go_back(n_bytes)
  @data.seek(-n_bytes, IO::SEEK_CUR)
end

#read_bytes(n_bytes) ⇒ String

Reads a specified number of raw bytes from the current position.

Parameters:

  • n_bytes (Integer) —

    the number of bytes to read

Returns:

  • (String) —

    the raw bytes as a binary string



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# File 'lib/ips/binary_reader.rb', line 60

def read_bytes(n_bytes)
  @data.read(n_bytes)
end

#read_int16 ⇒ Integer

Reads a 16-bit big-endian integer (2 bytes) from the current position.

Returns:

  • (Integer) —

    the 16-bit integer value



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# File 'lib/ips/binary_reader.rb', line 51

def read_int16
  bytes = @data.read(2).bytes
  (bytes[0] << 8) | bytes[1]
end

#read_int24 ⇒ Integer

Reads a 24-bit big-endian integer (3 bytes) from the current position.

Returns:

  • (Integer) —

    the 24-bit integer value



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# File 'lib/ips/binary_reader.rb', line 43

def read_int24
  bytes = @data.read(3).bytes
  (bytes[0] << 16) | (bytes[1] << 8) | bytes[2]
end

#read_string(size) ⇒ String

Reads a string of specified size from the current position.

Parameters:

  • size (Integer) —

    the number of bytes to read

Returns:

  • (String) —

    the string read from the data



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# File 'lib/ips/binary_reader.rb', line 36

def read_string(size)
  @data.read(size)
end