Class: Cabriolet::Models::SZDDHeader

Inherits:
Object
  • Object
show all
Defined in:
lib/cabriolet/models/szdd_header.rb

Overview

Represents an SZDD file header

SZDD files are single-file compressed archives using LZSS compression. They were commonly used with MS-DOS COMPRESS.EXE and EXPAND.EXE commands.

Constant Summary collapse

FORMAT_NORMAL =

SZDD format types

:normal
FORMAT_QBASIC = 
:qbasic

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(format: FORMAT_NORMAL, length: 0, missing_char: nil, filename: nil) ⇒ SZDDHeader

Initialize a new SZDD header

Parameters:

  • format (Symbol) (defaults to: FORMAT_NORMAL) —

    Format type (:normal or :qbasic)

  • length (Integer) (defaults to: 0) —

    Uncompressed size

  • missing_char (String, nil) (defaults to: nil) —

    Missing filename character

  • filename (String, nil) (defaults to: nil) —

    Original filename



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# File 'lib/cabriolet/models/szdd_header.rb', line 37

def initialize(format: FORMAT_NORMAL, length: 0, missing_char: nil,
               filename: nil)
  @format = format
  @length = length
  @missing_char = missing_char
  @filename = filename
end

Instance Attribute Details

#filename ⇒ String?

Original or suggested filename

Returns:

  • (String, nil) 


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# File 'lib/cabriolet/models/szdd_header.rb', line 29

def filename
  @filename
end

#format ⇒ Symbol

Format of the SZDD file (:normal or :qbasic)

Returns:

  • (Symbol) 


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# File 'lib/cabriolet/models/szdd_header.rb', line 16

def format
  @format
end

#length ⇒ Integer

Uncompressed file size in bytes

Returns:

  • (Integer) 


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# File 'lib/cabriolet/models/szdd_header.rb', line 20

def length
  @length
end

#missing_char ⇒ String?

Missing character from the original filename (NORMAL format only) Commonly the last character (e.g., ‘t’ in ‘file.txt’ -> ‘file.tx_’)

Returns:

  • (String, nil) 


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# File 'lib/cabriolet/models/szdd_header.rb', line 25

def missing_char
  @missing_char
end

Instance Method Details

#normal_format? ⇒ Boolean

Check if this is a NORMAL format SZDD file

Returns:

  • (Boolean) 


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# File 'lib/cabriolet/models/szdd_header.rb', line 48

def normal_format?
  @format == FORMAT_NORMAL
end

#qbasic_format? ⇒ Boolean

Check if this is a QBASIC format SZDD file

Returns:

  • (Boolean) 


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# File 'lib/cabriolet/models/szdd_header.rb', line 55

def qbasic_format?
  @format == FORMAT_QBASIC
end

#suggested_filename(compressed_filename) ⇒ String

Generate suggested output filename from compressed filename

Parameters:

  • compressed_filename (String) —

    The compressed filename

Returns:

  • (String) —

    Suggested output filename



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# File 'lib/cabriolet/models/szdd_header.rb', line 63

def suggested_filename(compressed_filename)
  return compressed_filename unless normal_format? && @missing_char

  # Replace trailing underscore with missing character
  # Pattern: ends with .XX_ where XX is any 2+ characters
  compressed_filename.sub(/\.(\w+)_$/, ".\\1#{@missing_char}")
end