linux man page for exit

EXIT(P) 						     POSIX Programmer's Manual							   EXIT(P)

NAME
       exit - cause the shell to exit

SYNOPSIS
       exit [n]

DESCRIPTION
       The  exit  utility  shall cause the shell to exit with the exit status specified by the unsigned decimal integer n.  If n is specified, but
       its value is not between 0 and 255 inclusively, the exit status is undefined.

       A trap on EXIT shall be executed before the shell terminates, except when the exit utility is invoked in that trap itself,  in  which  case
       the shell shall exit immediately.

OPTIONS
       None.

OPERANDS
       See the DESCRIPTION.

STDIN
       Not used.

INPUT FILES
       None.

ENVIRONMENT VARIABLES
       None.

ASYNCHRONOUS EVENTS
       Default.

STDOUT
       Not used.

STDERR
       The standard error shall be used only for diagnostic messages.

OUTPUT FILES
       None.

EXTENDED DESCRIPTION
       None.

EXIT STATUS
       The  exit status shall be n, if specified. Otherwise, the value shall be the exit value of the last command executed, or zero if no command
       was executed. When exit is executed in a trap action, the last command is considered to be the command that executed immediately  preceding
       the trap action.

CONSEQUENCES OF ERRORS
       Default.

       The following sections are informative.

APPLICATION USAGE
       None.

EXAMPLES
       Exit with a true value:

	      exit 0

       Exit with a false value:

	      exit 1

RATIONALE
       As  explained in other sections, certain exit status values have been reserved for special uses and should be used by applications only for
       those purposes:

	126   A file to be executed was found, but it was not an executable utility.

	127   A utility to be executed was not found.

       >128   A command was interrupted by a signal.

FUTURE DIRECTIONS
       None.

SEE ALSO
       Special Built-In Utilities

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technol-
       ogy -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
       Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and  the  original  IEEE
       and  The  Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained
       online at http://www.opengroup.org/unix/online.html .

IEEE
/The Open Group						       2003								   EXIT(P)