While this is all fine and dandy, things like development and multi-tasking can prove to be a little frustrating when connecting to a remote location and requiring more than one window open. Although a typical command line pretty much prevents this from happening, using GNU Screen or Byobu can make things a lot smoother. One window, multiple command lines.

As most developers will tell you, having multiple windows available to you is a godsend. It’s particularly useful when you have scripts to run in the background that generate output, but you don’t want to fork them as a daemon. Now, with GNU Screen and Byobu, you can do this easily, and even make your screen look snazzy as well. The only drawback to these utilities is that they are a little hard to get used to. In this post, I will quickly outline some of the key combinations which I use regularly.

GNU Screen and Byobu Simplified

The number one thing to remember about every command you use is Ctrl+A, which will be written as C-a. This is picked up by screen and will tell the utility that the next characters typed will be commands for screen to interpret. Keeping in mind that all keys are case-sensitive (as most things are in Linux), take a look at some of the commands below:

C-a C - Create a new screen window

C-a A - Rename the screen

C-a C-a - Go back to the previous window

C-a <0-9> - Switch to screen #0-9 (quick toggle)

C-a " - View a list of the current screens, which will allow you to select one from the list

C-a ' - Enter a screen number to switch to (slower version of C-a <0-9>)

C-a d - Detach the whole screen session and fork to the background. Very useful for remote sessions you want to leave open. The command "screen -r" will resume your screen session.

C-a <Escape> - Scroll up through your command line "history" and see what output you previously got. Hitting <Escape> again cancels it.

With the introduction of Byobu in Ubuntu 9.10, you can also get some statistics added to the bottom of your command line window to help keep you informed about the state of the system you are running on. Hitting F9 in session will bring up the menu for customization, which can make your screen session look pretty awesome. Instead of using screen to start your screen session, simply use byobu instead. Easy as pie.

If you have any questions about GNU Screen or Byobu, let me know and I’ll see what I can do to answer them. Stay tuned on Friday for another issue of “Five Things” (hopefully).

As always, I welcome your feedback; just post a comment below!

[View with PicLens]

It’s not like me to gush over operating systems. Particularly looking at what we’ve dealt with in the past. If we’re lucky, we got stability in an OS, but usually at the expense of it looking terrible. This year seems to have caused things to change, however. With the release of the Windows 7 RC, Microsoft has restored a good amount of the faith that it lost after churning out the load of crap that it called Vista.

The open source community is never far behind, and Canonical’s Ubuntu 9.10 operating system is a work of art. Seriously. I would frame it and mount it on my wall if I could. Unfortunately I can’t, so all I can do is gush about it and tell people about all of it’s amazing features. Non-techies: just smile-and-nod your way through this post .

Ubuntu One

Cloud computing is all the rage these days, and Ubuntu has jumped on the bandwagon by presenting One, a personal cloud for the synchronization of files across multiple Ubuntu computers. Set up your account, get your 2 gigs of free space, move files into the Ubuntu One folder, and let them sync. Easy as pie.

ext4 Filesystem

Following in Fedora’s footsteps, Ubuntu has set ext4 as 9.10’s default filesystem. Although you won’t make the switch if you upgrade, fresh installs will feel the warm glow of ext4 during their install.

Uncomplicated Firewall

One of my main complaints with Ubuntu’s previous setups is that it fails to include a firewall by default, and that has been remedied in 9.10, with the introduction of ufw, the uncomplicated firewall. No more sifting through the iptables’s man pages to figure out how to add a simple allow rule; ufw makes firewall management easy.

Faster Load Times with Upstart

Another popular trend recently has been the goal of reducing boot times as much as possible. Fedora Project made waves as they aimed for a 20 second boot time from BIOS to login page. Although they were a little short of their goal, they made some important headway, showing that not every single scrap needs to be loaded and cached on boot. Ubuntu has carried this forward and has made a similar goal. Although they don’t mention any specific time-related goals, they made the switch to Upstart, which makes the loading page look smooth and cuts the boot time significantly.

Thanks for giving this a read, everyone. If you like what you see, or have any suggestions for further writings, drop me a line in the comments section below and give me a vote on Reddit or Digg. I read each and every one of your comments: I promise

By popular demand of a few of my friends, I’m putting up a small sampling of the photos I’ve taken with it over the past few days. Although I’m still getting used to the lens, I’m really happy with the results so far. You can check out the full album of new photos right here.

On the way home from an event a couple weeks ago, I was talking with a friend about the hassle of all the paperwork we have to go through every time we have a lesson; we need to fill out transaction logs for each payment, keep track of every person’s attendance for each class, and also mark it on their membership form that they attended and paid for that class. A single person dropping in to that class requires writing on three sheets of paper. When you’re trying to run everybody through quickly, that starts becoming an issue.

This friend, being the kind of person that seems to regurgitate good ideas on demand, suggested to me, “Brian, you’re a developer. Just write a program to do it for you. You’re learning Ruby and Rails, so you can do a web-based backend and a GUI frontend. Problem solved!”. Thus, I sat down and started planning. Rails seems to be yet another one of those languages that lacks any decent documentation or tutorials. If you plan on learning it, pick up “Agile Web Development With Rails“. It is by far the best development book I have ever read. If it’s any sort of selling point, one of the authors created the Rails framework; if he doesn’t know how to use the framework, nobody does.

As a method for potentially helping me brainstorm, I’ve decided to spill out some of my ideas and goals here. I’m only going to discuss a few ideas here; while I would normally immediately distribute this idea into the public domain, I’ve decided to keep this one closed source. If you have any suggestions or ideas, let me know and I will give you credit. Better yet, if you’re interested in this software, get in touch and we can discuss it.

Goals for Dance Site

• Members: Keep track of all members, regardless of how long ago they joined. Eliminate the need to fill out a new membership form every semester. Each member should be assigned a member number, which can be put on a barcode. Keep track of personal information, interests, and attendance. Gather statistics/metrics from attendance vs. month/day/semester, etc.
• Memberships: Handle multiple membership types, including drop-in. Integrate with finances to determine when a user has paid for their membership through drop-ins. Support for online payments through Paypal (ie. Mastercard, Visa, eCheck, etc.)
• Finances: handle per-lesson incomes. Support for multiple lessons per day. Keep track of what is taught during that lesson. Provide unlockable content for each lesson; attendance to that lesson unlocks the content for that member; refresher videos, class notes, etc. Support for discounted membership dates/times.
• Graduated system: attendance of X number of events allows you to attend higher level classes. Ability to override by administrator.
• Mailing List: Separate old members by current members, allowing for class updates to be sent to current members, while global events to be sent to all. Ability to unsubscribe.

But I digest

While casually browsing the rewards catalog online, I was going through the gift cards and subscriptions. I happened to notice a new section for charities. Under there, you have redeem 170 Air Miles to donate $20 to one of three charities: Kids Help Phone, Special Olympics Canada, and the World Wildlife Fund. Unfortunately, Air Miles has yet to add any more charities, but I sincerely hope that they add more than those three. I’ve made a firm decision to redeem a donation for every item I redeem on there.

I’ve never seen this on a rewards site, and I think it’s a great thing to do. Think about how many reward miles you have. When was the last time you redeemed them? Do you think you could spare a few to help a good cause? I hope the answer is yes. Some people don’t donate to charities because they can’t afford it. Now that you can use Air Miles, this should make things a little easier. Alternatively, redeem a gift certificate somewhere you would normally shop, and use the saved money to a charity of your choice. Either way, it’s a free donation.

Just a little food for thought.

I’ve been recently programming a proxy in the Ruby programming language, which is known for its code elegance. When you know how to use it, it’s a great language. The problem, however, comes when to learning about the API in the language. To put it bluntly, the documentation is crap. To be more specific, a good amount of it is incomplete, and those sections that are completed fail to follow a consistent fashion. To put things in perspective, there are 108 core libraries included in the Ruby documentation; over half of those libraries have incomplete documentation.

Now, this isn’t that much of an issue if you know how to use the language; after all, there’s no need to go to the documentation when you know the language. The problem comes when you are like me, learning how to use the language, and don’t know what any of the constants for the sockets library do, which is a bit of a problem when you need to program a proxy. See where I’m going with this?

Maybe I’m complaining because I’ve been spoiled on PHP’s phenomenal documentation, which is an amazing feat when it comes to documentation. All of the functions are properly laid out with plenty of cross-references, and tell you exactly what to expect for each and every function. The documentation is a work of art, I kid you not. Don’t believe me? Try learning how to do something complex in PHP using the documentation only, then try to do the same in Ruby.

I have heard some people make the argument that Ruby is open source and relies on its members to do the documentation, hence the lack of it. While I understand this argument, it doesn’t entirely make sense. Ruby has a large band of dedicated followers (think Jehovah’s Witnesses-style) who should have filled in the 1.9 documentation by now. Thinking about it from another perspective, PHP is a free and open source language as well, and look at the detail in there compared to Ruby.

All I’m saying is that Ruby needs to step up its game a bit, otherwise it will have trouble competing for those people looking at learning a new language. If it wasn’t for an amazing IBM document on Ruby socket programming, I would have moved on to another language by now.

Anyways, tune in this Friday for something different. I realize programming isn’t everybody’s cup of tea, so I’m hoping to branch off into something a little different for those of you who either find computers boring, or those of you that simply don’t understand them. As always, I appreciate you reading, and I appreciate even more those of you who tell a friend about my blog .

After having my iPhone for the past month or so, I’ve found very few problems with it. In fact, I’ve never had a problem  yet.

Well, that’s not completely true. I’ve never had a problem until earlier this week, when the new firmware was released. After about 24 hours of running my phone, I noticed two significant changes. First of all, my battery life was dropping faster than a kid coming off of a caffeine high. Secondly, my phone took a whole 3 seconds (yes, three – I counted) to respond to the “slide to unlock” bar. Those were two things that I was not willing to put up with.

After doing some reading up on the subject, I noticed that I wasn’t alone. Some people blamed the firmware, while others blamed the users. I blame both; clearly the issue wasn’t universal. A hard reset (ie. not using the “slide to power off” slider) seemed to be a temporary fix, but I wanted something more permanent. It seemed the only way to fix this was to do a DFU factory restore. The only catch is that when your phone restarts, you have to create a new phone profile, and NOT restore an existing backup.

The process was relatively painless. I only lost a few photos and my text messages (I’d love to have a way of backing up text messages!), but aside from that I got all of my old data back after loading it on again.  The reset seems to have done the trick; here’s hoping it stays that way.

Opening up my email, I notice the vulnerability in my inbox, and a message attached asking me to find all the servers in the government which might be vulnerable to this exploit. Now, as you can imagine, it’s not like there’s 50 servers in the government. This isn’t a situation where you go to each server manually and check for the vulnerability. This worked out to be a perfect situation to use nmap.

Nmap, as I had mentioned last post, is a security scanner. It’s powerful: really, REALLY powerful. There’s so many command line switches that they have to use two characters for a lot of them, and they’re case sensitive as well. To top it all off, it also provides scripting support. In layman’s terms, you tell it to jump, and it asks you how high, how many flips it should do, what music should be playing in the background, and what the acrobat’s costumes should look like. You get the picture.

Anyways, the task was put before me to determine which servers were vulnerable, and how many FTP services could simply be turned off. After acquiring a list of IP addresses of assets, I sorted the list, changed each IP to refer to the class C subnet (255.255.255.0 or /24), and remove duplicates. I then came up with a list of IPs which had an FTP service. Some had closed ports, and others were filtered. Some of them were also open. A few quick grep commands and I had narrowed down the list to open Windows boxes. Below, I have the nmap command that I used to find all the servers with FTP running on them. I’d be curious to see if anyone has come up with a similar command that might be useful for this same purpose, and where improvements can be made.

./nmap -T4 -PS21 -p21 -O --max-rtt-timeout 200 --initial-rtt-timeout 150 --min-hostgroup 100 -oG /tmp/WindowsFTP.grep -iL ../WindowsServers24

This might seem like an odd topic for a geek to discuss. After all, I’m supposed to be glued to my computer, make obtuse references to nerdy shows and movies, and have a natural inability to talk to women. While all of the above may or may not be true (heh), I also found myself two years ago to have an interest in swing dancing, thanks to a friend who convinced me to go to the University of Manitoba Swing Dance Club (UMSwing) open house (thanks Jacklynn!). Although initially I didn’t think I would enjoy it that much, I found myself addicted by the end of that open house, and walked out that night with a full membership. I’m still shocked that I’m even capable of dancing, but regardless, it’s a great way to get some exercise, meet new people, and get out of the house.

Two years later, and I’m on the executive committee for UMSwing as their omnipotent web administrator. I’ve met a lot of great people through the club, and by being on the executive committee, I can hopefully give back to a club which has helped me a lot. One of the events that is happening in just over a week is this semester’s open house, which I will be MCing. The club puts on one open house per semester, usually within the first few weeks. We pride ourselves on being able to teach anybody to dance, regardless of skill level. You don’t need to bring a partner to dance with, and you don’t need experience. We do some demos, teach you basic Jive, and do some social dancing. Oh yeah, and there’s a bunch of prizes that we will give away.

• Multi-Purpose Room (MPR), 2nd Floor University Center, University of Manitoba
• September 16, 2009 @ 7:00pm – 11:00pm
• Free!
• Prizes!
• No experience required!
• No partner required!

So, if you have nothing to do that night, come out and enjoy yourself.

UMSwing’s classes tend to be geared towards beginner swing dance. If you happen to have swing experience, HepCat Studio is a swing studio that is starting up today at 6:00pm. The first class today is free, and they will teach both beginner and intermediate swing dancing. You can find their website over at http://www.winnipegswing.com.

So, I will continue with random technological rants and whatnot next Friday. Methinks that my next post will probably discuss my upcoming server build and the parts involved. Although I had posted on it a while back, I’ve solidified my decisions for the next server incarnation. It will be awesome. Very, very awesome.