Logging out depends on the UNIX shell (command line parser) and/or the windowing system (if logged in at a UNIX workstation) you are using.

By default, typing Control-D will exit any of the UNIX shells. In this case, Control-D indicates the end of file; here the end of the standard input (stdin) stream. Be careful when using programs that use Control-D to terminate; typing one too many Control-Ds may actually log you out of the system prematurely. Most UNIX shells allow this feature to be disabled by setting a shell variable called "ignoreeof". When set, the user must type exit or logout, depending on the shell, to either leave the current shell or logout of the machine completely.

The following table summarizes the different shells and their various means of termination: 

	ignoreeof variable	logout command	exit command
sh	no	no	yes
ksh	yes	no	yes
csh/tcsh	yes	only for login shell	only for subshell
bash	yes	only for login shell	yes