atexit
register a function to be called on exit
You're viewing an older version of this page (#3473). View the current version.
INTERFACE
#include <stdlib.h>
int atexit ( void (*function)(void) )DESCRIPTION
The atexit function registers the given function to be called at program exit, whether via exit or via return from the program's main. Functions so registered are called in reverse order; no arguments are passed.
These functions must not call exit; if it should be necessary to terminate the process while in such a function, the _exit function should be used. Alternatively, the function may cause abnormal process termination, for example by calling abort.
At least 32 functions can always be registered, and more are allowed as long as sufficient memory can be allocated.
Example 1
#include <stdio.h>
#include <stdlib.h>
void bye()
{
printf("Bye bye!\n");
}
void main()
{
// register the bye() function
atexit(bye);
// this first executes the function bye()
// and then exits with error message 0
exit(0);
}Output:
Bye bye!ERRORS
| ENOMEM | No memory was available to add the function to the list. The existing list of functions is unmodified. |