GConf was a system used by the

GNOME A gnome () is a mythological creature and diminutive spirit in Renaissance magic and alchemy, introduced by Paracelsus in the 16th century and widely adopted by authors, including those of modern fantasy literature. They are typically depict ...

desktop environment for storing configuration settings for the desktop and

applications Application may refer to: Mathematics and computing * Application software, computer software designed to help the user to perform specific tasks ** Application layer, an abstraction layer that specifies protocols and interface methods used in a ...

. It is similar to the

Windows Registry The Windows Registry is a hierarchical database that stores low-level settings for the Microsoft Windows operating system and for applications that opt to use the registry. The kernel, device drivers, services, Security Accounts Manager, a ...

. It was deprecated as part of the GNOME 3 transition. Migration to its replacement, GSettings and dconf, is ongoing. Changes to this system are controlled by GConfd, a

daemon A demon is a malevolent supernatural being, evil spirit or fiend in religion, occultism, literature, fiction, mythology and folklore. Demon, daemon or dæmon may also refer to: Entertainment Fictional entities * Daemon (G.I. Joe), a character ...

. GConfd watches out for changes to the

database In computing, a database is an organized collection of data or a type of data store based on the use of a database management system (DBMS), the software that interacts with end users, applications, and the database itself to capture and a ...

, and when they are changed, it applies the new settings to applications using it. This technology is known as "auto-apply", compared to "explicit-apply", which requires users to press an OK or Apply button to make changes come into effect. The term "instant-apply" is sometimes used, compared to plain "apply". The GConf database by default uses a system of directories and

XML Extensible Markup Language (XML) is a markup language and file format for storing, transmitting, and reconstructing data. It defines a set of rules for encoding electronic document, documents in a format that is both human-readable and Machine-r ...

files, stored in a directory called ~/.gconf. GConf can also use other backends, such as a database server, but XML file storage is the most common configuration. The application gconf-editor is provided to allow users to change settings manually, but it is not normally used for

end-user In product development, an end user (sometimes end-user) is a person who ultimately uses or is intended to ultimately use a product. The end user stands in contrast to users who support or maintain the product, such as sysops, system administrato ...

preferences.

Architecture

GConf is currently based on the C implementation of

CORBA The Common Object Request Broker Architecture (CORBA) is a standard defined by the Object Management Group (OMG) designed to facilitate the communication of systems that are deployed on diverse platforms. CORBA enables collaboration between sy ...

named ORBit. Its architecture consists of a session daemon that initializes various sources of configuration schemas on user login. Each source is based on a specific backend that translates the key and value pairs that compose the configuration

; the default backend is based on

. At this time, this is the only working backend for GConf, although an

LDAP The Lightweight Directory Access Protocol (LDAP ) is an open, vendor-neutral, industry standard application protocol for accessing and maintaining distributed Directory service, directory information services over an Internet Protocol (IP) networ ...

backend existed in embryonic form. Each source can also be set to read-only, in order to create a default basic configuration, e.g. in a corporate

network Network, networking and networked may refer to: Science and technology * Network theory, the study of graphs as a representation of relations between discrete objects * Network science, an academic field that studies complex networks Mathematics ...

. The values inside the GConf database are indexed using a

path A path is a route for physical travel – see Trail. Path or PATH may also refer to: Physical paths of different types * Bicycle path * Bridle path, used by people on horseback * Course (navigation), the intended path of a vehicle * Desir ...

string in the form of /path/to/application/key. The proper way to access the GConf database held by the GConf daemon is to use the GConfClient

GObject The GLib Object System, or GObject, is a free software, free software library providing a portable object system and transparent cross-language interoperability. GObject is designed for use both directly in C (programming language), C programs ...

-based class.

Changes notification

When writing an application that uses GConf, one should never directly poll the database. Instead, one should attach a

callback Callback may refer to: * Callback (comedy), a joke which refers to one previously told * Callback (computer programming), callable (i.e. function) that is passed as data and expected to be called by another callable. * Callback (telecommunication ...

to a given key, thus using a model-view-controller (MVC) paradigm. Each time an application changes the value bound to a specific key, the notification callbacks will be invoked.

Schemas

An application using GConf should provide a description for each key it creates inside the GConf database. This configuration meta-data is also stored inside the configuration database, and is called a ''schema''; it could contain a (possibly localized) descriptive text, the valid type of the value bound to a key, and a default value.

Bindings

Like many libraries in the

platform, GConf can be accessed using various programming languages, such as C,

C++ C++ (, pronounced "C plus plus" and sometimes abbreviated as CPP or CXX) is a high-level, general-purpose programming language created by Danish computer scientist Bjarne Stroustrup. First released in 1985 as an extension of the C programmin ...

Perl Perl is a high-level, general-purpose, interpreted, dynamic programming language. Though Perl is not officially an acronym, there are various backronyms in use, including "Practical Extraction and Reporting Language". Perl was developed ...

Java Java is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea (a part of Pacific Ocean) to the north. With a population of 156.9 million people (including Madura) in mid 2024, proje ...

, C#, VB.NET and

Python Python may refer to: Snakes * Pythonidae, a family of nonvenomous snakes found in Africa, Asia, and Australia ** ''Python'' (genus), a genus of Pythonidae found in Africa and Asia * Python (mythology), a mythical serpent Computing * Python (prog ...

References

External links

* *
Gnome2::GConf Perl Module
* {{GNOME Free system software GNOME obsolete