Application Menu

Foreground and Background Processes

To background a process:

bg

To foreground a process:

fg

To stop or suspend a process in order to manipulate its state:

Control z

To list the processes running on your workstation and their PID numbers:

ps -e (or -ef)
ps -a

Type man ps for other options.

To kill a process:

kill PID#
or
Control c

A large number of applications for the Solaris platform are available on Eos/Unity. Some are available from the main Application Menu, and others must be brought up from the command line.

Launching Applications from the Application Menu

To bring up the Application Menu (see figure in left column), move the cursor into the gray background. The cursor changes to an X. Hold down the middle mouse button of the three-button mouse, and the Application Menu pops up. The arrows on the Application Menu indicate that there is more than one application available in some categories. These are listed in submenus (also called cascading menus because one menu drops off another in cascade fashion).

To move into a submenu, pull the pointer down the list to the menu item you want. Then pull to the right, as the arrow indicates, and a submenu appears. Drag up or down this submenu to the application you want and release. This action launches the application and brings it up in its own window. Sometimes it takes awhile for the application to launch, so do not keep selecting it or you will get multiple copies of it running on your machine.

Launching Applications from the Command Line with add

Most Solaris applications are brought up from the command line and require two commands to launch. The first command is add followed by the name of the software package you want to use. This command sets up the software on your workstation and runs any startup programs that are part of the package. A second command launches the program and brings it into a window on the screen.

eos& add software
eos& launchcommand

If you do not remember the commands, type add at the shell prompt (eos%, unity%, etc.) to list the programs and the commands to execute them. When a program is added, a message usually appears telling you what command to use to execute (bring up) the program.

Background and Foreground Processes

Programs running on your computer are called processes, and they exist in one of three states: background, foreground, or stopped. If you type an ampersand (&) after the executing command, it tells the system to run the program in the background. The shell prompt is returned and
you can continue to type commands in the terminal window.

If you do not type the ampersand, the program still runs, but you are not able to type commands in the terminal window you used to launch the program. In this situation, the process is running in the foreground, and it has read and write access to the controlling terminal. The shell must
wait for the processing to finish before returning the prompt.

If you decide you want to background a process that has already been launched in the foreground, type Control z (hold down the Control key and type z). This command puts the process in a stopped or suspended state and gives you back the prompt. Type bg to background the process. To bring a stopped process to the foreground, type fg.

Unix and Linux assign a unique reference number, called a process identification (PID) number, to each process running. Users refer to the PID when they want to affect a process in some way, such as to terminate or kill it. To see what processes are running on your workstation, use the
ps -e (or -ef) command if you are on a Sun. To kill a process running, type kill followed by the PID number assigned to the process. Sometimes a command or process can also be aborted by typing Control c.

Note: When launching an application, whether from the command line or the Application Menu, you often must wait awhile before it appears on-screen (more than a minute at times). Be patient. Do not keep launching it again and again. If you do, you will eventually get multiple copies of the program running on your machine. You do not need more than one copy of a program taking up memory and slowing down the processing of the machine.

See also Files and Commands and Managing Directories.

"add" List for Sun Solaris Applications

In an Xterm window, type add to list available applications. Type add and the software package, followed by an executing command to launch the program, e.g.,

eos& add software
eos& launchcommand

Definitions

background process
command line interface
foreground process
graphical user interface
pid
process
prompt
terminal
shell
Unix

Information Technology and Engineering Computer Services (ITECS)
College of Engineering, North Carolina State University, Raleigh, NC 27695
Comments to eoshelp@ncsu.edu. URL: http://www.eos.ncsu.edu/

This support page is for students, faculty, and
staff at North Carolina State University.