Department of Engineering

IT Services

The "start" command on linux (draft)

The start command on our linux machines is designed primarily for staff to make computer-based labs easy for students to use. Staff can try things out using set-up files in their own filespace before having those files installed centrally. Using the same mechanism, users can create various personalised "start set-ups".

Using start

For some lab sessions a special command is provided so that the files and programs for the sessions are made available. Students doing the 1A Trading lab for example can type start 1ATrading. Users will need to consult the course document to see what needs to be typed. If they type start by itself then they'll see a list of start set-ups that are ready to use. These set-ups are also available via the appsicon icon on the central system's linux terminals.

Creating start set-ups

Staff wanting to have a start set-up created can mail their requirements to helpdesk. You'll need to suggest a name for the set-up (preferably beginning with 1A, 1B, 3 or 4) and describe what actions should happen.

Those familiar with unix can create and test a set-up themselves before asking to have it installed. The same method used to create prototype set-ups can also be used to create personalised set-ups. First you'll need to create a directory with the same name as the proposed set-up. For example, if you wanted people to type start nuclear you could create a folder in your home directory called nuclear.

Within this you can have 2 special files.

  • start - The actual "start" script. It needs to be made executable. Use this to copy files, add icons to the desktop, and launch programs - e.g. matlab. Please launch all programs in the background (i.e. with &). This "start" script is compulsory. For historical reasons, if a script called start.pre exists, that's run first.
  • stop - A script which gets run at the end of the session. Use this to remove per-session desktop icons, etc.

You can also have a directory called extras. All *.desktop files in this directory are copied to the user's desktop folder at login time.

Once you think the set-up is ready to try, you need to run start in such a way that it will look in your file-space for set-up files rather than in the default /export/teach/linux/start/ folder. start takes notice of an environmental variable called STARTDIR to determine where it should look, so if you wanted to try the nuclear example mentioned above you could type

      STARTDIR=~ start nuclear

(the '~' symbol being short-hand for your home directory).

Creating desktop icons

You can create a desktop icon (a "Launcher") using the 2nd item in the menu you get when clicking with the right-button on the background window. You'll be invited to choose the type of launcher, the icon, and the action. Creating a launcher will cause a file to be created in your Desktop folder. teaching_support will need a copy of that file if the icon's part of your lab's set-up.

For example, if the code below on the left is copied as Fast Feedback.desktop into a user's Desktop folder, they'll get the Fast Feedback icon on the right.

 
[Desktop Entry]
Encoding=UTF-8
Version=1.0
Type=Application
Terminal=false
Name[en_GB]=Fast Feedback
Exec=feedback
Icon[en_GB]=/opt/gnome/share/pixmaps/ximian-evolution-email.png
Name=Fast Feedback
Icon=/opt/gnome/share/pixmaps/ximian-evolution-email.png
icon

Some icons are in /usr/share/pixmaps/.

Installing

Contact helpdesk when you're ready to have the start environment installed. Indicate if you want the option to appear in a section under the "Applications" button in the taskbar.