_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.
Return Value
_onexit returns a pointer to the function if successful or NULL if there is no space to store the function pointer.
Remarks
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.
Requirements
Routine |
Required header |
|---|---|
_onexit |
<stdlib.h> |
For more compatibility information, see Compatibility in the Introduction.
Example
// 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;
}
Output
This is executed first.
This is executed next.
.NET Framework Equivalent
System::Diagnostics::Process::Exited