C atexit function sets a function to call when exiting normally

Syntax

C atexit function has the following syntax.

Header

C atexit function is from header file stdlib.h.

Description

C atexit function causes the function pointed to by func to be called upon normal program termination.

C atexit function returns zero if the function is successfully registered as a termination function and nonzero otherwise.

At least 32 termination functions can be registered, and they will be called in the reverse order of their registration.

Example

Use C atexit function to call a function when exiting normally.

#include <stdlib.h>
#include <stdio.h>
/*from ww w .  j a  v a  2  s.co  m*/
void done(void);

int main(void)
{
  if(atexit(done)){
        printf("Error in atexit().");
  }
  return 0;
}

void done(void)
{
  printf("Hello There");
}

The code above generates the following result.