Add original unix v6

source/s1/init.c

@@ -0,0 +1,219 @@
+#define	tabsize	20
+#define	all	p = &itab[0]; p < &itab[20]; p++
+#define	ever	;;
+#define	single	0173030
+#define	reboot	0173040
+char	shell[]	"/bin/sh";
+char	minus[]	"-";
+char	runc[]	"/etc/rc";
+char	init[]	"/etc/init";
+char	ifile[]	"/etc/ttys";
+char	utmp[]	"/etc/utmp";
+char	wtmpf[]	"/usr/adm/wtmp";
+char	ctty[]	"/dev/tty8";
+int	fi;
+struct
+{
+	int	flag;
+	int	line;
+	char	coms[2];
+} line;
+struct	tab
+{
+	int	pid;
+	int	line;
+	int	comn;
+} itab[tabsize];
+
+struct {
+	char	name[8];
+	char	tty;
+	char	fill;
+	int	time[2];
+	int	wfill;
+} wtmp;
+
+main()
+{
+	register i;
+	register struct tab *p, *q;
+	int reset();
+
+	/*
+	 * if not single user,
+	 * run shell sequence
+	 */
+
+	if(getcsw() != single) {
+		i = fork();
+		if(i == 0) {
+			open("/", 0);
+			dup(0);
+			dup(0);
+			execl(shell, shell, runc, 0);
+			exit();
+		}
+		while(wait() != i);
+		close(creat(utmp, 0644));
+		if ((i = open(wtmpf, 1)) >= 0) {
+			seek(i, 0, 2);
+			wtmp.tty = '~';
+			time(wtmp.time);
+			write(i, &wtmp, 16);
+			close(i);
+		}
+	}
+
+	/*
+	 * main loop for hangup signal
+	 * close all files and
+	 * check switches for magic values
+	 */
+
+	setexit();
+	signal(1, reset);
+	for(i=0; i<10; i++)
+		close(i);
+	switch(getcsw()) {
+
+	case single:
+	error:
+		termall();
+		i = fork();
+		if(i == 0) {
+			open(ctty, 2);
+			dup(0);
+			execl(shell, minus, 0);
+			exit();
+		}
+		while(wait() != i);
+
+	case reboot:
+		termall();
+		execl(init, minus, 0);
+		reset();
+	}
+
+	/*
+	 * open and merge in init file
+	 */
+
+	fi = open(ifile, 0);
+	q = &itab[0];
+	while(rline()) {
+		if(line.flag == '0')
+			continue;
+		for(all)
+			if(p->line==line.line || p->line==0) {
+				if(p >= q) {
+					i = p->pid;
+					p->pid = q->pid;
+					q->pid = i;
+					p->line = q->line;
+					p->comn = q->comn;
+					q->line = line.line;
+					q->coms[0] = line.comn;
+					q++;
+				}
+				break;
+			}
+	}
+	close(fi);
+	if(q == &itab[0])
+		goto error;
+	for(; q < &itab[tabsize]; q++)
+		term(q);
+	for(all)
+		if(p->line != 0 && p->pid == 0)
+			dfork(p);
+	for(ever) {
+		i = wait();
+		for(all)
+			if(p->pid == i) {
+				rmut(p);
+				dfork(p);
+			}
+	}
+}
+
+termall()
+{
+	register struct tab *p;
+
+	for(all)
+		term(p);
+}
+
+term(ap)
+struct tab *ap;
+{
+	register struct tab *p;
+
+	p = ap;
+	if(p->pid != 0) {
+		rmut(p);
+		kill(p->pid, 9);
+	}
+	p->pid = 0;
+	p->line = 0;
+}
+
+rline()
+{
+	static char c[4];
+
+	if(read(fi, c, 4) != 4 || c[3] != '\n')
+		return(0);
+	line.flag = c[0];
+	line.line = c[1];
+	line.comn = c[2];
+	return(1);
+}
+
+dfork(ap)
+struct tab *ap;
+{
+	register i;
+	register char *tty;
+	register struct tab *p;
+
+	p = ap;
+	i = fork();
+	if(i == 0) {
+		signal(1, 0);
+		tty = "/dev/ttyx";
+		tty[8] = p->line;
+		chown(tty, 0);
+		chmod(tty, 0622);
+		open(tty, 2);
+		dup(0);
+		execl("etc/getty", minus, p->coms, 0);
+		exit();
+	}
+	p->pid = i;
+}
+
+rmut(p)
+struct tab *p;
+{
+	register i, f;
+	static char zero[16];
+
+	f = open(utmp, 1);
+	if(f >= 0) {
+		i = p->line;
+		if(i >= 'a')
+			i =+ '0' + 10 - 'a';
+		seek(f, (i-'0')*16, 0);
+		write(f, zero, 16);
+		close(f);
+	}
+	f = open(wtmpf, 1);
+	if (f >= 0) {
+		wtmp.tty = p->line;
+		time(wtmp.time);
+		seek(f, 0, 2);
+		write(f, &wtmp, 16);
+		close(f);
+	}
+}