Make Your Life Easier With GNU Screen

July 29th, 2011 | Posted by Quixey in Technology - (2 Comments)

What do you do if you’re away from your work computer but need to fix a coding issue? Your instinct is probably to SSH in to fix the issue in a text editor. However, command line navigation and text editing often aren’t enough for important tasks, especially when you need webservers, database consoles or multiple shells running at the same time. One option is to open multiple SSH sessions on the same machine, but setting them up every time you connect becomes tiresome.

There’s a much better way to connect to your computer: a free utility called GNU Screen. It creates one or more virtual terminals in which you can run shells and whatever other programs you want.

Virtual terminal screen sessions can last much longer than a single SSH session. Even if your connection is lost, the session will just be detached – invisible, but continuing to run the same programs. Your session lasts until you explicitly kill the last virtual terminal in the session. That means you can open the web servers, consoles and shells you want once, and simply reattach to the same screen session if you need it again.

Virtual screen sessions have rather bewildering commands and a Spartan interface, but a .screenrc configuration file in your home directory can make your screen session more usable. The file displays the names and numbers of the current virtual terminals at the bottom of the screen.

Here is a simple but functional .screenrc file we’ve been using at Quixey:

autodetach on
startup_message off
defscrollback 30000
vbell off
term xterm-color
caption always "%{kB}%?%-Lw%?%{bw}%n*%f %t%?(%u)%?%{kB}%?%+Lw%?"

Here’s what all of that means:

  • autodetach on
        • Ensures that a sudden disconnection from the terminal (due to internet connection issues, for example) detaches your screen session instead of ending it.
  • startup_message off
        • Turns off the copyright message.
  • defscrollback 30000
        • Gives you 30000 lines of history for every virtual console. You can figure out how to scroll and search through it from the manual.
  • vbell off
        • Turns off a “visual bell” that flashes the screen every time the computer wants to alert you of something.
  • term xterm-color
        • Enables terminal colors.

That brings us to the last line:

caption always %{kB}%?%-Lw%?%{bw}%n*%f %t%?(%u)%?%{kB}%?%+Lw%?

This beauty formats the list of virtual terminals that’s displayed at the bottom of the screen. The components are as follows:

  • %{kB}
        • Set color to black on light blue.
  • ?%-Lw%?
        • Show the entries for the windows numbered greater than the active window.
  • %{bw}
        • Set color to blue on light gray.
  • %n*%f %t
        • Display the window’s number, flags# and program, for example “3*$ bash”.
  • %?(%u)%?
        • Show what other users are editing this window.
  • %{kB}
        • Set color to black on light blue.
  • %?%+Lw%?
        • Show the entries for the windows numbered higher than the active window.

A session is started by typing screen. If you disconnect, you can can reconnect by typing screen -x. Inside the screen session, ctrl+a is the (customizable) prefix key for all screen commands. The most important of these commands are:

  • ctrl-a c
        • Create a new virtual terminal.
  • ctrl+a A
        • Rename the current virtual terminal.
  • ctrl+a <number>
        • Switch to the virtual terminal of the number provided.
  • ctrl+a ctrl+a
        • Switch to the most recently viewed virtual terminal.
  • ctrl+a d
        • Detach the screen session.

That’s about all you need to know to start using screen like a pro! If you need more guidance and Google hasn’t helped, I recommend trying your luck with the 130+ page manual.

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Life-Changing Apps: Transportation

July 21st, 2011 | Posted by Quixey in Life-Changing Apps - (1 Comments)

Last week, we discussed how apps are transforming healthcare and medicine. Due to your positive feedback, we’ve decided to begin a series on life-changing apps. We will discuss apps that disrupt industries, improve your life, and change how the world works.

This week, we’ll focus on apps that change how you travel.

iBart

iBart was one of the first iPhone transportation apps, one that started a trend. Immediately after the iPhone was released, the developers at Pandav saw the importance of mobile transportation apps and got to work on iBart.

iBart manages your travel on the BART transportation system from anywhere in the San Francisco Bay area. It comes with a trip planner that doesn’t require internet access (so it works in tunnels), station information, scheduled arrivals, a beautifully designed BART map, and service advisories. Pandav has also released apps for Chicago, DC, and more, so be sure to see what they have available for public transportation in your area.

Getaround

Getaround was the winner of TechCrunch Disrupt NYC. It’s a peer-to-peer car rental marketplace – kind of like Airbnb for cars. As a car owner, you rent your car to Getaround users for an hourly fee. If you are borrowing a car, all you need to do is use the Getaround app to unlock the car you are borrowing. You can see all the cars available for rent on a map, or you can search for cars by address.

INRIX Traffic

INRIX Traffic

INRIX Traffic helps you find the fastest route to the places you want to go by helping you avoid traffic. It will show you the best times to leave for your destination, and you can save a set of favorite destinations or preferred routes. If commuting is a big part of your life, installing this app once might show you a route that saves you hours per year.

Taxi Magic

Our office loves Taxi Magic. Enter your location and a pick-up time, and the app will ping a cab in the area to get you. Even better, you can use the app to pay and add a tip at the end of your ride. You’ll also get an email receipt. You need to enter your credit card info and address before you can get started, but once you do, grabbing a cab is easy.

Apps have become an integral part of travel. It’s rare these days to travel for more than a few miles without loading some kind of app. Taking advantage of the best tools available makes travel far easier, whether by helping you worry less, finding you a taxi, or by showing you routes you never knew existed.

We’re always on the lookout for great apps. What transportation apps do you use?

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Life-Changing Apps: Healthcare Industry

July 14th, 2011 | Posted by Quixey in Life-Changing Apps - (1 Comments)

Quixey is built on the idea that apps are powerful. Apps have drastically changed our daily lives, and we’re starting to see them change industries.

Apps are particularly promising in the healthcare and medicine industry. Web and mobile-based tools now exist that can vastly improve your health, or even save your life.

We’ve listed a few of the most interesting apps below – take a look, and perhaps you’ll find something for you.

HeartWise Blood Pressure Tracker

This iPhone app is truly amazing. Enter your data to track your weight, resting heart rate, and blood pressure. The app will use this data to calculate your blood pressure, pulse, and body mass index. Over time the app builds trends to help you monitor your health.

It takes some discipline to continually add data to HeartWise. Even so, this app could be incredibly useful and promising if you build that data entry into your schedule. You can export your data to perform analysis or show your doctor.

Skin Scan

This app is essentially a personal skin cancer prevention system. Just take a picture of your skin, and this app will assess your risk of skin cancer by scanning and analyzing your moles.

You can also track cases over time to analyze their progression, helping you monitor your health between doctor appointments.

AirStrip

AirStrip is one of many apps being used by hospitals. It is designed for doctors to remotely monitor their patients, pulling information from hundreds of different patient monitors and ECG machines. This helps eliminate time delay in the clinical assessment and treatment of patients. The app is accessible anywhere with cellular or Wi-Fi access.

These are just a few examples, but the point is clear: technology is making huge strides towards goals like remote medical diagnosis, real time health monitoring and personalized treatment. On an individual level, these apps have the potential to drastically improve your quality of life. On the industry level, apps could be revolutionary.

We are moving into the era of digital medicine. Each of these apps can replace or augment an entire test or process at the doctors office, saving you time, money, and health. Apps aren’t just mobile games anymore – they’re pieces of technology that change the way you live.

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Explaining The App Discovery Problem

July 8th, 2011 | Posted by Quixey in Functional Search | Functional Web - (1 Comments)

Without Quixey, app search often requires knowing the app’s name or  keywords in its app store description. But you shouldn’t need to know an app’s name to find it – it’s hard enough to memorize app names like Uber, Shazam and Kayak.

Quixey lets you find apps just by answering the question:

Apps are solutions to everyday problems like calling cabs, identifying music and planning trips. People know what they want to do, but they don’t know the app that can help them do it. Unfortunately, current app stores aren’t good at searching for apps by function.

For example, “games for 3 year olds” returns nothing in the iPhone app store:

This is most likely because the query “games for 3 year olds” is a long query. The App Store’s search struggles with queries written in plain English and queries longer than three words. This makes it difficult to find what you need.

In contrast, Quixey is designed to process queries exactly how you naturally write them.

For example, see our results for the same query:

Our core technology (functional search) allows us to find good results, even when the official stores can’t. How do we do it? We gather outside data. Since our search engine is constantly scanning the web for descriptions, reviews, and blogs about apps, it learns exactly what each app can do. This enables Quixey to find apps that do what you want, no matter how you describe them.

Let’s take a look at another example on the App Store.

The selection found with this query is seemingly random. The results include 2 video editors, an ecards app and a few other random apps. On the other hand, results for “edit photos” are much better. Despite the fact that these queries are so similar, the average app search engine gets confused with one and not the other.

At Quixey, understanding natural language is one of our specialties and we don’t run into the same problem.

The past two examples represent a universal problem. I can’t tell you how many times I’ve heard “I want to find X and all I get is random apps,” or “I always think there must be an app for that, but my app store doesn’t have anything.” You might know the feeling.

Of course, I don’t mean to pick on iPhone. The same problem exists across all platforms.

So, the takeaway: Quixey is different because you don’t need to know an app’s name or its exact description to find what you want. Just answer the question: what do you want to do?

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