Add original unix v6

source/s2/wall.c

@@ -0,0 +1,68 @@
+char	mesg[3000];
+int	msize;
+struct
+{
+	char	name[8];
+	char	tty[2];
+	int	time[2];
+	int	junk;
+} utmp[50];
+
+main(argc, argv)
+char *argv[];
+{
+	register i, *p;
+	int f;
+
+	f = open("/etc/utmp", 0);
+	if(f < 0) {
+		printf("utmp?\n");
+		exit();
+	}
+	read(f, utmp, sizeof utmp);
+	close(f);
+	f = 0;
+	if(argc >= 2) {
+		f = open(argv[1], 0);
+		if(f < 0) {
+			printf("%s?\n", argv[1]);
+			exit();
+		}
+	}
+	while((i = read(f, &mesg[msize], sizeof mesg - msize)) > 0)
+		msize =+ i;
+	close(f);
+	for(i=0; i<sizeof utmp/sizeof utmp[0]; i++) {
+		p = &utmp[i];
+		if(p->tty[0] == 0)
+			continue;
+		sleep(1);
+		sendmes(p->tty[0]);
+	}
+}
+
+sendmes(tty)
+{
+	register i;
+	register char *s;
+
+	i = fork();
+	if(i == -1) {
+		printf("try again\n");
+		return;
+	}
+	if(i)
+		return;
+	s = "/dev/ttyx";
+	s[8] = tty;
+	i = open(s, 1);
+	if(i < 0) {
+		printf("cannot open tty%c\n", tty);
+		exit();
+	}
+	close(1);
+	dup(i);
+	printf("Broadcast Message ...\n\n");
+	write(1, mesg, msize);
+	exit();
+}