task spooler: a queue system for your commands

April 15, 2017 Leave a comment

In 2013 I wrote a program that allowed the user to put the copy and move file operations in a queue (blog post here).

Today I heard about a more general solution called task spooler (AUR, PPA). Task spooler can queue any Unix command, it has several options, so it’s a better solution than my previous approach.

Installation
Under Manjaro I couldn’t install it because the upstream URL was dead at that time. So I downloaded the task-spooler_1.0.orig.tar.gz file, converted it to deb format with the command alien, and then installed it with dpkg. Under Ubuntu the executable is called tsp.

Usage
Here is a short video about its usage where I heard about this program for the first time: https://www.youtube.com/watch?v=wv8D8wT20ZY. Some examples with the most important options:

$ ts                       # show info
$ ts cp -r movies  /tmp    # put this task in the queue
$ ts -c ID                 # show the output of a running task
$ ts -C                    # clear finished tasks
Categories: Uncategorized Tags: , , ,

Record audio in good quality

April 13, 2017 Leave a comment

Problem
I wanted to create some simple tutorial videos using a screen recording software (with gtk-recordMyDesktop to be precise), but the audio quality was terrible. There was a constant white noise in the background. I could reduce the noise with Audacity but 1) I couldn’t eliminate the noise, 2) it distorted my voice, and 3) the audio became weaker.

Solution
I had a cheap headphone / microphone that was connected with a jack plug. I think there was also some inference that caused the noise. So I bought a USB headset (Logitech H390) and the damn noise is gone! It works very well for me.

I tried it under Manjaro and here is how to make it work. Plug it and start Audacity. Next to the microphone icon there is a dropdown list. Select your headset and try to record some audio.

Try “pavucontrol” too. Under the Recording tab I had to select “Headset H390 Analog Mono”. Talk in the microphone and the sound feedback line should be moving.

How to record audio with gtk-recordMyDesktop? Start “pavucontrol” and “gtk-recordMyDesktop” too. In gtk-recordMyDesktop, go to Advanced -> Sound tab. Next to the device name I had “DEFAULT”. Change it to “pulse” (without quotes). Start recording with gtk-recordMyDesktop. Now switch to pavucontrol and go the Recording tab. At the bottom select “Show: Applications”. Now recordmydesktop should appear. Next to it there is a dropdown menu where select “Headset H390 Analog Mono”. It should do the trick.

Java profiling

March 18, 2017 Leave a comment

YourKit is a great Java profiling tool. It is a commercial software but you can get a free 15-day evaluation license key for a fully functional version of the profiler.

The past week I was working on a Java project and the software was very slow. Using YourKit I could easily find the bottleneck. It turned out that 94% of the time was spent in a function that I implemented in a naive way. Choosing a better algorithm the software got much faster. A profiler is really useful…

For Java I use Eclipse. YourKit integrates in Eclipse perfectly through an Eclipse plugin.

Python profiling

Here is an excellent post about Python profiling.

Categories: java, python Tags: , ,

[Eclipse] use spaces instead of TABs

March 18, 2017 Leave a comment

Here is how to use spaces instead of TABs in the Eclipse IDE:

  1. Click Window -> Preferences.
  2. Expand Java -> Code Style.
  3. Click Formatter.
  4. Click the Edit button.
  5. Click the Indentation tab.
  6. Under General Settings, set Tab policy to: Spaces only.
  7. Click OK to apply the changes.

Tip from here.

Categories: Uncategorized Tags: , ,

Some IMDb alternatives

March 10, 2017 Leave a comment

IMDb shut down its message boards in February, 2017. Read more here. This is a shame. When I watched a movie, I loved to read the opinions of other people on this forum. It was a very stupid decision from IMDb and I’m sure I’ll visit their site much less.

Here are some alternatives:

Unfortunately, these sites won’t replace the good old message boards…

Project idea: write a script that takes the title of a movie and opens these sites in tabs. The sites in the tabs show the selected movie.

funny git commits

February 19, 2017 Leave a comment

Some funny GitHub commits:

Found here.

What to do if shit happened.

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increase sudo timeout

February 12, 2017 Leave a comment

Problem
You want to increase the sudo password remember timeout.

Solution
Run “sudo visudo“, then add this line to the end:

Defaults    timestamp_timeout=60

Where 60 means 60 minutes. If you specify -1, then the password is never forgotten (which is not a good idea IMO).

Tip from here.

Categories: bash, linux Tags: ,