ref: ca940abd2cd7eb26c804c9bb6110010f2178c2ea
dir: /sys/src/ape/lib/ap/stdio/atexit.c/
#include <unistd.h>
#define NONEXIT 34
extern int (*_atexitfns[NONEXIT])(void);
int
atexit(int (*f)(void))
{
int i;
for(i=0; i<NONEXIT; i++)
if(!_atexitfns[i]){
_atexitfns[i] = f;
return(0);
}
return(1);
}