A Few Things to Try

• Safer picture downloading. Adapt the picture-downloading/file-renaming program to your computer by adding some safety features to make sure you never overwrite a file. A few methods you might find useful are File.exist? (pass it a filename, and it will return true or false) and exit (like if return and Napoleon had a baby—it kills your program right where it stands; this is good for spitting out an error message and then quitting).

• Build your own playlist. For this to work, you need to have some music ripped to your computer in some format. We’ve ripped a hundred or so CDs, and we keep them in directories something like music/​genre/​artist_and_cd_name/​track_number.ogg. (I’m partial to the ogg format, though this would work just as well with mp3s or whatever you use.)

  Building a playlist is easy. It’s just a regular text file (no YAML required, even). Each line is a filename, like this:

  music/world/Stereolab--Margarine_Eclipse/track05.ogg

  What makes it a playlist? Well, you have to give the file the m3u extension, like playlist.m3u or something. And that’s all a playlist is: a text file with an m3u extension.

  So, have your program search for various music files and build you a playlist. Use your shuffle method here to mix up your playlist. Then check it out in your favorite music player (Winamp, MPlayer, and so on)!

• Build a better playlist. After listening to playlists for a while, you might start to find that a purely random shuffle just doesn’t quite seem…mixed up enough. (Random and mixed up are not at all the same thing. Random is totally clumpy.) For example, here’s an excerpt from a playlist I made a while back of Thelonius Monk and Faith No More:

  music/Jazz/Monk--Nutty/track08.ogg

  music/Jazz/Monk--London_Collection_1/track05.ogg

  music/Jazz/Monk--Nutty/track13.ogg

  music/Jazz/Monk--Round_Midnight/track02.ogg

  music/Jazz/Monk--Round_Midnight/track14.ogg

  music/Jazz/Monk--Round_Midnight/track15.ogg

  music/Jazz/Monk--Round_Midnight/track08.ogg

  music/Rock/FNM--Who_Cares_A_Lot_2/track02.ogg

  music/Rock/FNM--Who_Cares_A_Lot_2/track08.ogg

  music/Rock/FNM--Who_Cares_A_Lot_1/track02.ogg

  music/Rock/FNM--Who_Cares_A_Lot_2/track01.ogg

  Hey! I asked for random! Well, that’s exactly what I got…but I wanted mixed up. So, here’s the grand challenge: instead of using your old shuffle, write a new music_shuffle method. It should take an array of filenames (like those listed previously) and mix them up good and proper.

  You’ll probably need to use the split method for strings. It returns an array of chopped-up pieces of the original string, split where you specify, like this:

  awooga = ​'this/is/not/a/daffodil'​.split ​'/'​

  puts awooga

  this

  is

  not

  a

  daffodil

  Mix it up as best you can!