I had a Game Boy once. I could play it just about anywhere, and battery life - for the time - was great. I lost it at one point, and replaced it with a Game Gear, which sucked the life out of 6 AA batteries rather quickly. The Game Boy Color was actually decent on battery life, but since it didn’t have a backlight, you had to play it at very specific angles.

Ever have a machine you can only ssh into through another machine? It’s a very common situation in the Technion. Here’s one way to get around it: Assume you can directly ssh into alpha, and from alpha you can ssh into beta. Have the following code in your ~/.ssh/config:

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Host beta
        Hostname 1.2.3.4  # IP Address of beta
        ProxyCommand ssh alpha nc -w 1 %h %p

This requires you to have nc (netcat) installed on alpha. Once you do that, you can run ssh beta directly from your own box.

These days I don’t stay at home often, but I do have an RSS/BitTorrent combo fetching me all kinds of neat stuff for me, so I can have it ready for me on the weekend. I love rtorrent, especially due to the fact that I can run it in screen, ssh home and see how things are doing (or add more torrent to the download). However, sometimes my net connection breaks down, computers gets shut off, or things like that. This week my router broke down, so I can’t even ssh home to manually start up rtorrent. My solution: A small script, which checks whether rtorrent is already running, and if not - runs it in a detached screen session. Run this with your favorite cron software.

Gnome 2.24 adds a new Time Tracking feature, which I would have found useful. I don’t have Gnome 2.24 at work, but I do have a Unix-based operating system… Here’s my new ~/bin/track:

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#!/bin/bash
date >> ~/time_tracking
vim ~/time_tracking +

Now, if I could only get vim to automatically hit “A” and space for me afterwards… (I’m betting there’s a way to do it, but AFAIK vim can only receive ex-mode commands as parameters).

Sometimes, when constructing a compound object, we are interested in exporting functionality while retaining encapsulation. For example, suppose we have a Secretary class:

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class Secretary
  def send_fax(destination, fax_contents)
    puts 'Sending fax "%s" to %s' % [fax_contents, destination]
  end

  def answer_call(call)
    # ...
  end

  # ...
end

Our Secretary provides a lot of useful functionality, that our Boss class would like to have. Boss would like to be able to say that he can send a fax, without having the user explicitly request his Secretary beforehand. The same goes for a lot of other methods Secretary provides. Instead of writing a stub function for each of these methods, it would be nice to do the following: