Class: HexaPDF::CLI::Modify

Inherits:
CmdParse::Command
  • Object
show all
Defined in:
lib/hexapdf/cli/modify.rb

Overview

Modifies a PDF file:

  • Decrypts or encrypts the PDF file.

  • Generates or deletes object and cross-reference streams.

  • Optimizes a PDF by merging the revisions of a PDF file and removes unused entries.

See: HexaPDF::Task::Optimize

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Modify

:nodoc:



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# File 'lib/hexapdf/cli/modify.rb', line 49

def initialize #:nodoc:
  super('modify', takes_commands: false)
  short_desc("Modify a PDF file")
  long_desc("    This command modifies a PDF file. It can be used to encrypt/decrypt a file, to optimize it\n    and remove unused entries and to generate or delete object and cross-reference streams.\n  EOF\n\n  options.on(\"--password PASSWORD\", \"-p\", String,\n             \"The password for decryption. Use - for reading from standard input.\") do |pwd|\n    @password = (pwd == '-' ? command_parser.read_password(\"Input file password\") : pwd)\n  end\n  options.on(\"--pages PAGES\", \"The pages to be used in the output file\") do |pages|\n    @pages = pages\n  end\n  options.on(\"--embed FILE\", String, \"Embed the file into the output file (can be used \" \\\n             \"multiple times)\") do |file|\n    @embed_files << file\n  end\n  options.on(\"--[no-]compact\", \"Delete unnecessary PDF objects (default: yes)\") do |c|\n    @compact = c\n  end\n  options.on(\"--object-streams MODE\", [:generate, :preserve, :delete],\n             \"Handling of object streams (either generate, preserve or delete; \" \\\n             \"default: preserve)\") do |os|\n    @object_streams = os\n  end\n  options.on(\"--xref-streams MODE\", [:generate, :preserve, :delete],\n             \"Handling of cross-reference streams (either generate, preserve or delete; \" \\\n             \"default: preserve)\") do |x|\n    @xref_streams = x\n  end\n  options.on(\"--streams MODE\", [:compress, :preserve, :uncompress],\n             \"Handling of stream data (either compress, preserve or uncompress; default: \" \\\n             \"preserve)\") do |streams|\n    @streams = streams\n  end\n\n  options.separator(\"\")\n  options.separator(\"Encryption related options\")\n  options.on(\"--decrypt\", \"Remove any encryption\") do\n    @encryption = :remove\n  end\n  options.on(\"--encrypt\", \"Encrypt the output file\") do\n    @encryption = :add\n  end\n  options.on(\"--owner-password PASSWORD\", String, \"The owner password to be set on the \" \\\n             \"output file. Use - for reading from standard input.\") do |pwd|\n    @encryption = :add\n    @enc_owner_pwd = (pwd == '-' ? command_parser.read_password(\"Owner password\") : pwd)\n  end\n  options.on(\"--user-password PASSWORD\", String, \"The user password to be set on the \" \\\n             \"output file. Use - for reading from standard input.\") do |pwd|\n    @encryption = :add\n    @enc_user_pwd = (pwd == '-' ? command_parser.read_password(\"User password\") : pwd)\n  end\n  options.on(\"--algorithm ALGORITHM\", [:aes, :arc4],\n             \"The encryption algorithm: aes or arc4 (default: aes)\") do |a|\n    @encryption = :add\n    @enc_algorithm = a\n  end\n  options.on(\"--key-length BITS\", Integer,\n             \"The encryption key length in bits (default: 128)\") do |i|\n    @encryption = :add\n    @enc_key_length = i\n  end\n  options.on(\"--force-V4\",\n             \"Force the use of encryption version 4 if key length=128 and algorithm=arc4\") do\n    @encryption = :add\n    @enc_force_v4 = true\n  end\n  syms = HexaPDF::Encryption::StandardSecurityHandler::Permissions::SYMBOL_TO_PERMISSION.keys\n  options.on(\"--permissions PERMS\", Array,\n             \"Comma separated list of permissions to be set on the output file. Possible \" \\\n             \"values: \#{syms.join(', ')}\") do |perms|\n    perms.each do |perm|\n      unless syms.include?(perm)\n        raise OptionParser::InvalidArgument, \"\#{perm} (invalid permission name)\"\n      end\n    end\n    @encryption = :add\n    @enc_permissions = perms\n  end\n\n  @password = nil\n  @pages = '1-e'\n  @embed_files = []\n  @compact = true\n  @object_streams = :preserve\n  @xref_streams = :preserve\n  @streams = :preserve\n\n  @encryption = :preserve\n  @enc_user_pwd = @enc_owner_pwd = nil\n  @enc_key_length = 128\n  @enc_algorithm = :aes\n  @enc_force_v4 = false\n  @enc_permissions = []\nend\n".gsub!(/^ */, ''))

Instance Method Details

#execute(input_file, output_file) ⇒ Object

:nodoc:



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# File 'lib/hexapdf/cli/modify.rb', line 149

def execute(input_file, output_file) #:nodoc:
  @compact = true unless @pages == '1-e'
  if @enc_user_pwd && !@enc_user_pwd.empty? && (!@enc_owner_pwd || @enc_owner_pwd.empty?)
    @enc_owner_pwd = @enc_user_pwd
  end

  HexaPDF::Document.open(input_file, decryption_opts: {password: @password}) do |doc|
    arrange_pages(doc) unless @pages == '1-e'
    @embed_files.each {|file|  doc.utils.add_file(file, embed: true)}

    doc.task(:optimize, compact: @compact, object_streams: @object_streams,
             xref_streams: @xref_streams)

    handle_streams(doc) if @streams != :preserve

    if @encryption == :add
      doc.encrypt(algorithm: @enc_algorithm, key_length: @enc_key_length,
                  force_V4: @enc_force_v4, permissions: @enc_permissions,
                  owner_password: @enc_owner_pwd, user_password: @enc_user_pwd)
    elsif @encryption == :remove
      doc.encrypt(name: nil)
    end

    doc.write(output_file)
  end
rescue HexaPDF::Error => e
  $stderr.puts "Error while processing the PDF file: #{e.message}"
  exit(1)
end