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NAME
atexit - register a function to run at process termination
SYNOPSIS
#include <stdlib.h> int atexit(void (*func)(void));
DESCRIPTION
The atexit() function shall register the function pointed to by func, to be called without arguments at
normal program termination. At normal program termination, all functions registered by the atexit()
function shall be called, in the reverse order of their registration, except that a function is called
after any previously registered functions that had already been called at the time it was registered.
Normal termination occurs either by a call to exit() or a return from main().
At least 32 functions can be registered with atexit().
After a successful call to any of the exec functions, any functions previously registered by atexit()
shall no longer be registered.
RETURN VALUE
Upon successful completion, atexit() shall return 0; otherwise, it shall return a non-zero value.
ERRORS
No errors are defined.
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
The functions registered by a call to atexit() must return to ensure that all registered functions are
called.
The application should call sysconf() to obtain the value of {ATEXIT_MAX}, the number of functions that
can be registered. There is no way for an application to tell how many functions have already been
registered with atexit().
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
exit() , sysconf() , the Base Definitions volume of IEEE Std 1003.1-2001, <stdlib.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition,
Standard for Information Technology -- 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 .