Add original unix v6

source/s2/who.c

@@ -0,0 +1,68 @@
+/*
+ * who
+ */
+
+int	fout;
+int	buf[256];
+
+main(argc, argv)
+char **argv;
+{
+	char *s, *cbuf;
+	int n, fi, i;
+	int tty;
+	struct {
+		char name[8];
+		char tty;
+		char pad1;
+		int time[2];
+		char pad2[2];
+	} *p;
+
+	s = "/etc/utmp";
+	if(argc == 2)
+		s = argv[1];
+	fi = open(s, 0);
+	if(fi < 0) {
+		write("cannot open wtmp\n", 17);
+		exit();
+	}
+	fout = dup(1);
+	close(1);
+	if (argc==3)
+		tty = ttyn(0);
+
+loop:
+	n = read(fi, buf, 512);
+	if(n == 0) {
+		flush();
+		if (argc==3)
+			write(fout, "Nobody.\n", 8);
+		exit();
+	}
+
+	p = &buf;
+	for(p = &buf; (n =- 16)>=0; p++) {
+		if (argc==3 && tty!=p->tty)
+			continue;
+		if(p->name[0] == '\0' && argc==1)
+			continue;
+		for(i=0; i<8; i++) {
+			if(p->name[i] == '\0')
+				p->name[i] = ' ';
+			putchar(p->name[i]);
+		}
+		for(i=0; i<3; i++)
+			putchar("tty"[i]);
+		putchar(p->tty);
+		cbuf = ctime(p->time);
+		for(i=3; i<16; i++)
+			putchar(cbuf[i]);
+		putchar('\n');
+		if (argc==3) {
+			flush();
+			exit();
+		}
+	}
+	goto loop;
+}