|
Cancel Cable: How Internet Pirates Get Free Stuff |
Chapter 5 – Archives
If you’ve ever downloaded a .zip file or received one attached to an email message, then you have experience with archives. Pirates need more than the simple support that Windows and OS X have for archives.
About Archives
An archive is a collection of any number of files and folders compressed and combined into a single file. Compressing files reduces the space they occupy on drives and decreases the time they take to download, so it’s common for people to share their files as archives. Common, but misguided. The formats used for video, picture, audio, application, game, book, disk-image, and almost every other type of file distributed over BitTorrent are already compressed, so archiving doesn’t reduce download time and adds the extra step of decompressing after the download finishes. (You can’t repeatedly compress a file to make it ever smaller; otherwise, you’d ultimately be able to compress all the world’s data into a single byte.)
Archives also limit choice. A season of 24 distributed as a single archive file rather than as 24 separate video files forces you to download the entire archive rather than only the episodes you want (say, all but the middle 20 episodes). In fact, an archived media file is a yellow flag that the torrent’s creator might be forcing you to download more than just the files of interest. Force-fed files are often spam, malware, or self-promotion in the form of small text, executable, or internet-shortcut files (see Chapter 4). Happily, you can extract only the files that you want from the archive and toss the rest without a glance.
Often, archives arrive split into smaller parts (one file per part), which are reassembled silently and automatically when you open the archive. Split archives are a holdover from the space-limited days of yore. Now, we have cheap terabyte drives, cloud storage, and filesystems that can accommodate monster files.
Archives also tend to shorten a torrent’s life. After extracting an archive’s original files, it’s natural to delete the now-redundant archive. This loss makes it impossible to seed (or reseed) the torrent.
By fashion or inertia, archives remain part of piracy.
Types of Archives
Archives, like other classes of files, come in various formats. The most common file format used for torrents is RAR, followed distantly by ZIP. (In mainstream computing, ZIP is king and RAR is rare.) RAR beats ZIP as a compression format because it produces much smaller archives in about the same amount of time. When you finish downloading an archive, you extract copies of its original files to your drive, leaving the archive itself unchanged. Extracting is also called unarchiving or unpacking. Conversely, making an archive file is called archiving or packing. For ZIP archives, there’s zipping and unzipping. You may encounter the odd torrent archived in 7Z, GZIP, TAR, SIT (StuffIt), or another format. These archives are all extracted in the same way. In general, approach non-RAR and non-ZIP archives with caution.
Working with Archives
Windows and OS X have built-in support for ZIP but not for RAR, so you must install a file archiver to extract files. Wikipedia lists file archivers 
. I use WinRAR for Windows and WinZip for OS X. Popular open-source archivers include 7-Zip and IZArc . All work similarly and support RAR, ZIP, and other formats.
ZIP files have the filename extension .zip and RAR files have the extension .rar. If a RAR archive is split into parts, its filenames end in
.part01.rar, .part02.rar, .part03.rar,...
or
.rar, .r00, .r01, .r02,...
To open an archive file, double-click it. Split archives self-assemble in the file archiver, provided their parts all are in the same folder. If you double-click an .r00 file (or any .rnn file), your OS might complain that it doesn’t know which program to use to open the file. To associate .rnn files with your file archiver, see Chapter 3. (WinRAR registers .rnn associations automatically on installation but most other archivers don’t.)
Archives work somewhat like folders in that they “contain” files, so archivers display an archive’s contents like files listed in a Windows Explorer or Finder window. Your archiver’s help system explains how to display, select, and extract files. The main operations are consistent across archivers:
- To extract files, select them in the archiver window (some archives contain only one file), click the Extract button, and then specify a destination folder. Extraction can take minutes for large archives.
- To select adjacent files in a list, click the first file and then either Shift-click the last file or press Shift+arrow key. To select nonadjacent files, Ctrl-click each file (or Command-click in OS X). To select all files, press Ctrl+A (or Command+A).
- Double-clicking a file in an archiver window opens it without copying it to your hard drive.
- You can drag files from an archiver window to the desktop or a folder window, where they auto-extract. Don’t use this method if maintaining the files’ original folder structure is important.
- Archivers can integrate with the shell, meaning that they can add commands to context menus in Windows Explorer or Finder. If you right-click an archive file and choose the “Extract Here” command, for example, the archive’s complete contents are extracted without actually launching the file archiver. For security, always double-click an archive and inspect its files in an archiver window before extracting them.
- Some archives come with a separate SFV (.sfv) or checksum file, created by the archiver. SFV stands for Simple File Validator. You can open this file in a text editor and, with a bit of technical skill, use its contents to determine whether the files downloaded correctly. Don’t bother: BitTorrent already takes care of file integrity by using its own checksums for each piece of a torrent. You can delete SFVs or omit them from your download altogether.