_onexit

Registers a routine to be called at exit time.

_onexit_t_onexit(_onexit_tfunc**);**

For additional compatibility information, see Compatibility in the Introduction.

Libraries

Return Value

_onexit returns a pointer to the function if successful, or NULL if there is no space to store the function pointer.

Parameter

func

Pointer to function to be called at exit

Remarks

The _onexit function is passed the address of a function (func) 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.

_onexit is a Microsoft extension. For ANSI portability use atexit.

Example

/* ONEXIT.C */

#include <stdlib.h>
#include <stdio.h>

/* Prototypes */
int fn1(void), fn2(void), fn3(void), fn4 (void);

void 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.

Process and Environment Control Routines

See Also   atexit, exit