Category: Computing

Have you ever wondered where your Skype chatlogs are saved so that Skype can show you a chatlog on your mobile of a chat you had done with your computer, and reportedly even if you have saving chatlogs disabled on your computer? I found that issue for the first time like a year ago, and […]

There can be many reasons for that. One that I did not know until now is that the symlink itself and the directory it points to have to have the same user as owner (group owner seems to be irrelevant). If not, it won’t work. You can change ownership of the symlink rather than the […]

This is an introduction to computer networks, with an emphasis on practically useful knowledge and on wi-fi technology. Where possible, it includes references to existing material. [Work in progress. At the moment, just the outline without links to existing material.]  Outline packet switching theory (incl. multiplexing) network speeds (gross and net data rate, MBit/s and kbyte/s) […]

In this case, I use the Note Everything Pro Android application for note-taking, and wanted a quick way to transfer these notes to the computer. For individual notes For transfering only one or a few notes, I found the zbarcam Linux application quite helpful. To get it, install package zbar-tools in Ubuntu 14.04 and higher […]

So I tried to export a huge FreeMind mindmap to LibreOffice / OpenOffice.org Writer format and tried, as usual, in Freemind: “File -> Export -> To OpenOffice.org Writer format …”. But that failed, as it exported only the first level of nodes and nothing else. This seems to be a bug in te FreeMind 1.0.0 […]

Symptoms When trying to start your Ruby application from within RubyMine using a “Run” or “Debug” configuration, you get an error message like this: /usr/share/ruby-rvm/rubies/ruby-1.9.2-p180/bin/ruby -e $stdout.sync=true;$stderr.sync=true;load($0=ARGV.shift) /usr/share/ruby-rvm/gems/ruby-1.9.2-p180/bin/unicorn_rails -l 0.0.0.0:5000 -E development -c ./config/unicorn.rb /usr/share/ruby-rvm/gems/ruby-1.9.2-p180/gems/bundler-1.1.3/lib/bundler/spec_set.rb:90:in `block in materialize’: Could not find rake-0.9.2.2 in any of the sources (Bundler::GemNotFound) from /usr/share/ruby-rvm/gems/ruby-1.9.2-p180/gems/bundler-1.1.3/lib/bundler/spec_set.rb:83:in `map!’ […] Process finished with […]

This is a bit of a tricky task because the package ruby_rvm from the Ubuntu 12.10 archives is naturally installed system-wide, but RubyMine only works with rvm that provides gems on a per-user basis [source]. The solution is to use the so-called “mixed mode” installation of rvm: installed system-wide, but gems and optionally rubies provided […]