Question

I have Qt application which should work on multiple platforms. One of those platforms is Linux. I am completely new in Linux world.

My application need to create and manage set of data files. After reading some links about linux directory structure I decided to store data files in /var/myapp directory and in its subdirectories.

Here is the problem: if my application runs without superuser privileges then it has no rights to create /var/myapp directory. Even if i will create directory manually (with sudo) my application will not have rights to write files there.

Is it possible to temporary elevate application’s permissions from Qt code to create /var/myapp directory and write files there?

Or possibly there is another place in Linux directory structure which is by default available for storing application’s data files?

Answer 1

You could distribute it without installation scripts, but you’d have to tell them to run it once as root… or have the app run itself as root using gksudo/kdesudo if its system wide data files do not exist.
The custom though is to make a package (.deb, .rpm, or even a .tar.gz that the user will extract himself) including all necessary files.

But linux (and OS X for that matter) are multi user systems. Are you sure your files belong in /var or /usr? If they’re created at runtime as you say, don’t they depend on user input? In which case you need to put them in some directory inside the user’s home directory (getenv(“HOME”)).