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.\" the American National Standards Committee X3, on Information
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.\"	$OpenBSD: exit.3,v 1.10 2004/05/03 17:21:13 millert Exp $
.\"
.Dd January 21, 2004
.Dt EXIT 3
.Os
.Sh NAME
.Nm exit, _Exit
.Nd perform normal program termination
.Sh SYNOPSIS
.Fd #include <stdlib.h>
.Ft void
.Fn exit "int status"
.Ft void
.Fn _Exit "int status"
.Sh DESCRIPTION
The
.Fn exit
and
.Fn _Exit
functions terminate a process.
.Pp
Before termination,
.Fn exit
performs the following operations in the order listed:
.Bl -enum -offset indent
.It
Call the functions registered with the
.Xr atexit 3
function, in the reverse order of their registration.
.It
Flush all open output streams.
.It
Close all open streams.
.It
Unlink all files created with the
.Xr tmpfile 3
function.
.El
.Pp
The
.Fn _Exit
function terminates without calling the functions registered with the
.Xr atexit 3
function.
The
.Ox
implementation of
.Fn _Exit
does not flush open output streams or unlink files created with the
.Xr tmpfile 3
function.
However, this behavior is implementation-specific.
.Pp
Lastly,
.Fn exit
and
.Fn _Exit
call
.Xr _exit 2 .
Note that typically
.Xr _exit 2
only passes the lower 8 bits of
.Fa status
on to the parent, thus negative values have less meaning.
.Sh RETURN VALUES
The
.Fn exit
and
.Fn _Exit
functions never return.
.Sh SEE ALSO
.Xr _exit 2 ,
.Xr atexit 3 ,
.Xr intro 3 ,
.Xr sysexits 3 ,
.Xr tmpfile 3
.Sh STANDARDS
The
.Fn exit
and
.Fn _Exit
functions conform to
.St -ansiC-99 .