1ATEXIT(3P) POSIX Programmer's Manual ATEXIT(3P)
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6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
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12 atexit - register a function to run at process termination
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15 #include <stdlib.h>
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17 int atexit(void (*func)(void));
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21 The atexit() function shall register the function pointed to by func,
22 to be called without arguments at normal program termination. At normal
23 program termination, all functions registered by the atexit() function
24 shall be called, in the reverse order of their registration, except
25 that a function is called after any previously registered functions
26 that had already been called at the time it was registered. Normal ter‐
27 mination occurs either by a call to exit() or a return from main().
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29 At least 32 functions can be registered with atexit().
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31 After a successful call to any of the exec functions, any functions
32 previously registered by atexit() shall no longer be registered.
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35 Upon successful completion, atexit() shall return 0; otherwise, it
36 shall return a non-zero value.
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39 No errors are defined.
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41 The following sections are informative.
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44 None.
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47 The functions registered by a call to atexit() must return to ensure
48 that all registered functions are called.
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50 The application should call sysconf() to obtain the value of
51 {ATEXIT_MAX}, the number of functions that can be registered. There is
52 no way for an application to tell how many functions have already been
53 registered with atexit().
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56 None.
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59 None.
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62 exit(), sysconf(), the Base Definitions volume of IEEE Std 1003.1-2001,
63 <stdlib.h>
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66 Portions of this text are reprinted and reproduced in electronic form
67 from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
68 -- Portable Operating System Interface (POSIX), The Open Group Base
69 Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
70 Electrical and Electronics Engineers, Inc and The Open Group. In the
71 event of any discrepancy between this version and the original IEEE and
72 The Open Group Standard, the original IEEE and The Open Group Standard
73 is the referee document. The original Standard can be obtained online
74 at http://www.opengroup.org/unix/online.html .
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78IEEE/The Open Group 2003 ATEXIT(3P)