

Listing 1: The file signal.h


/* signal.h standard header */
#ifndef _SIGNAL
#define _SIGNAL
#ifndef _YVALS
#include <yvals.h>
#endif
                /* type definitions */
typedef int sig_atomic_t;
typedef void _Sigfun(int);
                /* signal codes */
#define SIGABRT _SIGABRT
#define SIGINT  2
#define SIGILL  4
#define SIGFPE  8
#define SIGSEGV 11
#define SIGTERM 15
#define _NSIG   _SIGMAX /* one more than last code */
                /* signal return values */
#define SIG_DFL (_Sigfun *)0
#define SIG_ERR (_Sigfun *)-1
#define SIG_IGN (_Sigfun *)1
                /* declarations */
int raise(int);
_Sigfun *signal(int, _Sigfun *);
#endif


