ScreenProfiles

Summary

Screen is a powerful program that allows your terminal session to use multiple windows and retain context among multiple logins.

This package leverages screen's support of profiles and script to present a highly customized, configured screen with a task bar at the bottom of the window that shows system status, pending updates, and which window you are currently viewing (among other features).

Release Note

The Ubuntu Server has always had a command-line only interface, and has never included a graphical desktop, such as Gnome, KDE, or XFCE. We differ quite a bit from other Linux distributions in this respect. However, the default Ubuntu Server installation does include a window manager--screen. The screen-profiles package improves the usability, user-interface, and keybindings of the default screen installation.

Rationale

There exists a contingent of Ubuntu Server users (and an even larger contingent of potential Ubuntu Server users) who complain about the Server's lack of a graphical desktop. While adding Gnome/KDE/XFCE to the Server is still not realistic, we already provide a window manager--screen.

This specification is intended to provide the design for the screen-profiles package--a set of profiles and scripts that should make the screen utility even more useful for Ubuntu Server users.

Use Cases

  • Alice is using the tty console of an Ubuntu Server and would benefit from opening multiple shells/tabs/windows. She's not terribly familiar with the screen program, and is frankly intimidated by it.
  • Betty is using an ssh client to connect to an Ubuntu Server. She needs to start a long running job, background the process, drop her ssh session, and reattach later. She, too, has heard of screen, but doesn't entirely understand its capabilities.
  • Cindy and Debbie are working thousands of miles apart, but would like to do some crosstraining on their Ubuntu Server, looking at the same code and configuration files at the same time. VNC and other graphical utilities are not an option due to the lack of sufficient bandwidth. They know something about screen, but are not aware that both of them can simultaneously share the same screen session.
  • Eunice uses ssh to log into many Ubuntu Servers, and would like to immediately know, upon login, some key details about a given server. She's been using update-motd to do this, but she'd prefer having this information always available, and dynamically updated to her session as long as she's logged in. She's aware of screen, but doesn't grok the complicated language required to define status bars.

Assumptions

  • We will not be able to make everyone happy.
  • We will create a layout that is disagreeable to someone.
  • We will establish a keybinding that conflicts with something.

It's important to minimize these offenses by:

  • Gathering as much constructive feedback as possible and addressing the majority of Ubuntu Server users.
  • Vetting the semi-graphical layout by the experience Ubuntu Desktop team
  • Testing and verifying hotkeys in some set of common utilities (gnome-terminal, tty console?)
  • Establishing a framework that allows users to easily enable desired functionality, and disable undesirable functionality.

Design

GNU screen supports a ~/.screenrc file in each user's home directory, as well as global one in /etc/screenrc.

Furthermore, screenrc supports "include" functionality by means of the "source" directive. This is recursive. In other words, files can "source" other screen configuration files, etc.

Profiles

We hope to provide several stock "profiles" in:

  • /usr/share/screen-profiles/profiles

The user should be able to choose one of these stock profiles using:

  • select-screen-profile

This will establish a symbolic link to that profile in the user's ~/.screenrc-profile, which will be sourced in their ~/.screenrc.

The user can customize this profile by copying and modifying the code locally that we profile in /usr/share/screen-profiles, or by adding overrides in their local ~/.screenrc.

Keybindings

We hope to provides to useful "keybindings" that make certain tasks in screen easier in:

  • /usr/share/screen-profiles/keybindings

This is perhaps one of the most complicated aspects of this effort, as we must take care to ensure that they're useful, functional in multiple environments, and cause as few conflicts as possible.

The essential operations include:

  • Create a new window
  • Go to the previous window
  • Go to the next window
  • Close the current window
  • Detach from the session
  • Launch the screen configurator (and help)

Translations

We should strive to use gettext for translatability of screen-profiles as much as possible.

Status Programs

We hope to provide some helper scripts that gather status for display in the toolbar in:

  • /usr/share/screen-profiles/bin

The idea here is similar to the notification items in the Gnome or KDE taskbar. We should be able to provide information about:

  • the current OS and version
  • the number of package updates available
  • when a reboot is required
  • the number of cpu's
  • the current cpu speed
  • memory information
  • time/date

Ideally, these would be configurable, much like adding an "applet" to the taskbar.

Windows

We also may launch 2 or more useful "windows" by default, as defined in:

  • /usr/share/screen-profiles/windows

Again, this should be easily configurable, such that users can add/remove common windows from their setup on launch.

We may, for instance, launch with the screen-configurator in the first window by default, until such time as the user dismisses it and no longer wants it launched automatically in their setup.

Implementation

screen-profiles is under active development in the Launchpad Project and Bazaar:

screen-profiles has been packaged for Ubuntu and is currently in the proposed queue for Jaunty:

In the meantime, it is being published in DustinKirkland's PPA for Hardy, Intrepid, and Jaunty:

Once screen-profiles is accepted into the archive, we should continue testing and move for inclusion in main, and into the Ubuntu Server CD seed.

Test/Demo Plan

We will need to obtain significant testing input prior to inclusion in Ubuntu's Main Archive.

Unresolved issues

Discussion

Please file bugs at:

Please ask questions at:

CategorySpec

ScreenProfiles (last edited 2009-02-05 09:49:51 by port-213-160-23-156)