_onexit, _onexit_m
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The latest version of this topic can be found at _onexit, _onexit_m.
Registers a routine to be called at exit time.
_onexit_t _onexit( _onexit_t function ); _onexit_t_m _onexit_m( _onexit_t_m function );
Parameters
function
Pointer to a function to be called at exit.
_onexit returns a pointer to the function if successful or NULL if there is no space to store the function pointer.
The _onexit function is passed the address of a function (function) to be called when the program terminates normally. Successive calls to _onexit create a register of functions that are executed in LIFO (last-in-first-out) order. The functions passed to _onexit cannot take parameters.
In the case when _onexit is called from within a DLL, routines registered with _onexit run on a DLL's unloading after DllMain is called with DLL_PROCESS_DETACH.
_onexit is a Microsoft extension. For ANSI portability, use atexit. The _onexit_m version of the function is for mixed mode use.
| Routine | Required header |
|---|---|
_onexit | <stdlib.h> |
For more compatibility information, see Compatibility in the Introduction.
// crt_onexit.c
#include <stdlib.h>
#include <stdio.h>
/* Prototypes */
int fn1(void), fn2(void), fn3(void), fn4 (void);
int main( void )
{
_onexit( fn1 );
_onexit( fn2 );
_onexit( fn3 );
_onexit( fn4 );
printf( "This is executed first.\n" );
}
int fn1()
{
printf( "next.\n" );
return 0;
}
int fn2()
{
printf( "executed " );
return 0;
}
int fn3()
{
printf( "is " );
return 0;
}
int fn4()
{
printf( "This " );
return 0;
}
This is executed first. This is executed next.
System::Diagnostics::Process::Exited
Process and Environment Control
atexit
exit, _Exit, _exit
__dllonexit