1 .\" Copyright (C) 2001 Andries Brouwer <aeb@cwi.nl>.
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25 .TH EXIT 3 2013-02-14 "Linux" "Linux Programmer's Manual"
27 exit \- cause normal process termination
30 .B #include <stdlib.h>
32 .BI "void exit(int " status );
37 function causes normal process termination and the
38 value of \fIstatus & 0377\fP is returned to the parent
42 All functions registered with
46 are called, in the reverse order of their registration.
47 (It is possible for one of these functions to use
51 to register an additional
52 function to be executed during exit processing;
53 the new registration is added to the front of the list of functions
54 that remain to be called.)
55 If one of these functions does not return
58 or kills itself with a signal),
59 then none of the remaining functions is called,
60 and further exit processing (in particular, flushing of
62 streams) is abandoned.
63 If a function has been registered multiple times using
67 then it is called as many times as it was registered.
71 streams are flushed and closed.
76 The C standard specifies two constants,
77 \fBEXIT_SUCCESS\fP and \fBEXIT_FAILURE\fP,
80 to indicate successful or unsuccessful
81 termination, respectively.
85 function does not return.
87 SVr4, 4.3BSD, POSIX.1-2001, C89, C99.
90 It is undefined what happens if one of the
91 functions registered using
101 removes registrations created using
110 is slightly more portable
111 (to non-UNIX environments) than the use of 0 and some nonzero value
113 In particular, VMS uses a different convention.
115 BSD has attempted to standardize exit codes; see the file
120 the exit status must be transmitted to the
122 There are three cases.
123 If the parent has set
129 the status is discarded.
130 If the parent was waiting on the child
131 it is notified of the exit status.
132 In both cases the exiting
133 process dies immediately.
134 If the parent has not indicated that
135 it is not interested in the exit status, but is not waiting,
136 the exiting process turns into a "zombie" process
137 (which is nothing but a container for the single byte representing
138 the exit status) so that the parent can learn the exit status when
139 it later calls one of the
143 If the implementation supports the
146 is sent to the parent.
147 If the parent has set
149 it is undefined whether a
153 If the process is a session leader and its controlling terminal
154 is the controlling terminal of the session, then each process in
155 the foreground process group of this controlling terminal
158 signal, and the terminal is disassociated
159 from this session, allowing it to be acquired by a new controlling
162 If the exit of the process causes a process group to become orphaned,
163 and if any member of the newly orphaned process group is stopped,
169 sent to each process in this process group.
172 for an explanation of orphaned process groups.