Storing application preferences and data

Question

I am looking at creating some Ubuntu applications, but finding good resoures are hard.

I am using the quickly toolkit, but would really like some more insight. How does one normally store application preferences and settings in Linux / Ubuntu.

Is it as simple as creating a XML file and saving the information and then reading from said file on application bootstrap?

If someone can point me in a direction it would be greatly appreciated.

EDIT

This is something I wrote whilst waiting for a reply. Probably exactly what preferences does, but just coded out. You might find it usefull:

import ConfigParser, os # We need to be able to store and recal settings

#first try to read the config.cfg file
config = ConfigParser.RawConfigParser()
configFile = 'data/config.cfg'

# We need to set some defaults
monState = False
tueState = False
wedState = False
thurState = False
friState = False
satState = False
sunState = False

# Creating the Config file
def createConfigFile(fileName):
    print "CREATING CONFIG" # not needed, but nice for debugging
    config.add_section('Preferences')
    config.set('Preferences', 'mon', False)
    config.set('Preferences', 'tues', False)
    config.set('Preferences', 'wed', False)
    config.set('Preferences', 'thur', False)
    config.set('Preferences', 'fri', False)
    config.set('Preferences', 'sat', False)
    config.set('Preferences', 'sun', False)
    rewriteConfigFile(filename)

# After reading the config file, we can update configs in memory. 
# But this will save it to file for when the application is started up again. 
def rewriteConfigFile(filename):    
    with open(filename, 'wb') as configfile:
        config.write(configfile)

# Reading the config file 
def readConfigFile(fileName):
    print "READING CONFIG"  # not needed, but nice for debugging
    global monState, tueState, wedState, thurState, friState, satState, sunState
    monState = config.getboolean('Preferences', 'mon')
    tueState = config.getboolean('Preferences', 'tues')
    wedState = config.getboolean('Preferences', 'wed')
    thurState = config.getboolean('Preferences', 'thur')
    friState = config.getboolean('Preferences', 'fri')
    satState = config.getboolean('Preferences', 'sat')
    sunState = config.getboolean('Preferences', 'sun')

# If the config does not exist, create it, then read it. Otherwise simply read it
if not config.read(configFile):    
    createConfigFile(configFile)
    readConfigFile(configFile)    
else:
    readConfigFile(configFile)

Take a look at these questions: http://askubuntu.com/questions/59822/where-to-store-user-settings-for-an-app http://askubuntu.com/questions/4420/where-do-applications-typically-store-data — mivoligo, Nov 07 '12 at 10:54

score 2 · Answer 1 · answered Nov 08 '12 at 14:48

If you are storing user data, you typically save it under $HOME/.config/$YOURAPP/ (though the user can change this, so it's better to use xdg.BaseDirectory.xdg_config_home).

If you are using Python, I recommend the ConfigParser library which makes it easy to read and write structured config file data.

score 2 · Accepted Answer · answered Nov 08 '12 at 19:17

Quickly applications use the glib schemas for application preferences. A default schema is created in data/glib-2.0/schemas. It's an xml file called net.launchpad.XXXX.gschema.xml where XXXX is your application name.

Here's an example entry:

<?xml version="1.0" encoding="UTF-8"?>
<schemalist gettext-domain="drawers">
  <schema id="net.launchpad.drawers" path="/net/launchpad/drawers/">
    <key name="maxicons-row" type="i">
      <range min="1" max="15"/>
      <default>5</default>
      <summary>Maximum Icons per Row</summary>
      <description>Minimum value = 1 Max=15</description>
    </key>
  </schema>
</schemalist>

Key's can be integers (type="i"), boolean (type="b"), or floats (type="d"). Use only lower case and - in key names.

To access the settings and bind them to widgets, you can get them as follows (taken from the PreferencesXXXXWindow.py generated by quickly):

def finish_initializing(self, builder):# pylint: disable=E1002
    """Set up the preferences dialog"""
    super(PreferencesDrawersDialog, self).finish_initializing(builder)

    # Bind each preference widget to gsettings
    self.settings = Gio.Settings("net.launchpad.drawers")
    widget = self.builder.get_object('maxicons_row')
    self.settings.bind("maxicons-row", widget, "value", Gio.SettingsBindFlags.DEFAULT)

To read values for variables within a program you can do the following:

from gi.repository import Gio
settings = Gio.Settings("net.launchpad.drawers")
integer=settings.get_int("intsetting")
float = settings.get_double("floatsetting")
bool = settings.get_boolean("booleansetting")

Hope that helps.

Thank you Ian,that is definately more elegant then my solution which I ended up with. — Rudi Strydom, Nov 08 '12 at 20:28

score 0 · Answer 3 · answered Nov 07 '12 at 10:44

0

I dont have much work experience with linux. But the similar issue i faced while working on my application.

In linux, every application generates a file which includes all the settings. If its Linux own application, you can easily search for the file in " /etc/ " folder.

please provide some sample Application name for more details.

Hope this may help you find your way.

answered Nov 07 '12 at 10:44

skg

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/etc/ is for system-wide settings, not user settings. – mhall119 Nov 08 '12 at 14:49

Storing application preferences and data

3 Answers3