/*
 *  call-seq:
 *     Process.kill(signal, pid, ...)    => fixnum
 *  
 *  Sends the given signal to the specified process id(s), or to the
 *  current process if _pid_ is zero. _signal_ may be an
 *  integer signal number or a POSIX signal name (either with or without
 *  a +SIG+ prefix). If _signal_ is negative (or starts
 *  with a minus sign), kills process groups instead of
 *  processes. Not all signals are available on all platforms.
 *     
 *     pid = fork do
 *        Signal.trap("HUP") { puts "Ouch!"; exit }
 *        # ... do some work ...
 *     end
 *     # ...
 *     Process.kill("HUP", pid)
 *     Process.wait
 *     
 *  <em>produces:</em>
 *     
 *     Ouch!
 */

VALUE
rb_f_kill(argc, argv)
    int argc;
    VALUE *argv;
{
    int negative = 0;
    int sig;
    int i;
    char *s;

    rb_secure(2);
    if (argc < 2)
	rb_raise(rb_eArgError, "wrong number of arguments -- kill(sig, pid...)");
    switch (TYPE(argv[0])) {
      case T_FIXNUM:
	sig = FIX2INT(argv[0]);
	break;

      case T_SYMBOL:
	s = rb_id2name(SYM2ID(argv[0]));
	if (!s) rb_raise(rb_eArgError, "bad signal");
	goto str_signal;

      case T_STRING:
	s = RSTRING(argv[0])->ptr;
	if (s[0] == '-') {
	    negative++;
	    s++;
	}
      str_signal:
	if (strncmp("SIG", s, 3) == 0)
	    s += 3;
	if((sig = signm2signo(s)) == 0)
	    rb_raise(rb_eArgError, "unsupported name `SIG%s'", s);

	if (negative)
	    sig = -sig;
	break;

      default:
        {
	    VALUE str;

	    str = rb_check_string_type(argv[0]);
	    if (!NIL_P(str)) {
		s = RSTRING(str)->ptr;
		goto str_signal;
	    }
	    rb_raise(rb_eArgError, "bad signal type %s",
		     rb_obj_classname(argv[0]));
	}
	break;
    }

    if (sig < 0) {
	sig = -sig;
	for (i=1; i<argc; i++) {
	    int pid = NUM2INT(argv[i]);
#ifdef HAS_KILLPG
	    if (killpg(pid, sig) < 0)
#else
	    if (kill(-pid, sig) < 0)
#endif
		rb_sys_fail(0);
	}
    }
    else {
	for (i=1; i<argc; i++) {
	    Check_Type(argv[i], T_FIXNUM);
	    if (kill(FIX2INT(argv[i]), sig) < 0)
		rb_sys_fail(0);
	}
    }
    return INT2FIX(i-1);
}