session-installer

session-installer [package_names...]

[package_names...]
    One or more names of packages to install. These are typically proprietary software components or codecs (e.g., flashplugin-installer, ubuntu-restricted-extras).

--help
    Displays a help message with usage information. (Note: May not be explicitly documented for all versions as it's often an internal utility.)

--version
    Shows the version information of the utility. (Note: May not be explicitly documented for all versions as it's often an internal utility.)

session-installer is a utility primarily used in Ubuntu and its derivatives to facilitate the installation of proprietary software, multimedia codecs, and drivers that cannot be shipped by default due to licensing restrictions. It typically assists in setting up components like MP3 audio decoding, Microsoft TrueType fonts, Adobe Flash Player, and proprietary graphics drivers (e.g., NVIDIA, AMD).

Rather than being a general package manager, it often acts as an interactive wrapper or a backend component for tools like the "Restricted Formats Installer" or when installing meta-packages such as ubuntu-restricted-extras. It guides the user through license agreements and dependency resolution for these specific, often essential, non-free components, leveraging underlying package management tools like APT. Its purpose is to simplify the post-installation setup for common multimedia and hardware needs, often invoked automatically after a fresh installation or system upgrade.

This command is primarily specific to Ubuntu and Debian-based distributions. It requires an active internet connection to download the necessary packages. It deals with non-free or proprietary software, often necessitating user acceptance of End User License Agreements (EULAs) during the installation process. It is not intended as a general-purpose package management tool like apt.

session-installer is often invoked automatically by desktop environments, graphical tools like the Software Center (or its successors), or post-installation scripts (e.g., after installing ubuntu-restricted-extras). Users typically do not run it directly from the command line for general package management, but rather interact with a higher-level tool that calls session-installer as a backend.

A core function of session-installer is to present and manage the user's acceptance of End User License Agreements (EULAs) for the proprietary software it installs. This interactive step ensures compliance with licensing terms before installation proceeds.

The session-installer utility emerged as part of Ubuntu's broader effort to enhance user-friendliness and simplify the post-installation setup of common multimedia codecs and proprietary drivers. It abstracts the complexities of direct apt calls and EULA acceptance, integrating seamlessly with graphical installers and meta-packages like ubuntu-restricted-extras. Its development aligns with Ubuntu's philosophy of providing a complete out-of-the-box experience, despite licensing challenges for certain software components.

apt(8), dpkg(8), ubuntu-drivers(1), software-center(1)