System Functions

The ANSI standard includes some system functions for raising and responding to signals, non-local jumping, and so on.

Listing: ANSI-C system functions



void      abort(void);
int       atexit(void(* func) (void));

void      exit(int status);

char*     getenv(const char* name);

int       system(const char* cmd);

int       setjmp(jmp_buf env);

void      longjmp(jmp_buf env, int val);

_sig_func signal(int sig, _sig_func handler);

int       raise(int sig);

To process variable-length argument lists, the ANSI library provides the functions shown in the following listing, implemented as macros:

Listing: Macros with variable-length arguments



void va_start(va_list args, param);
type va_arg(va_list args, type);

void va_end(va_list args);