Add original unix v6

2018-01-27 22:35:41 +09:00
commit 2c7099ee50
664 changed files with 106254 additions and 0 deletions
@@ -0,0 +1,61 @@
+char dot[] ".";
+char dotdot[] "..";
+char root[] "/";
+char name[512];
+int file, off -1;
+struct statb {int devn, inum, i[18];}x;
+struct entry { int jnum; char name[16];}y;
+
+main() {
+	int n;
+
+loop0:
+	stat(dot, &x);
+	if((file = open(dotdot,0)) < 0) prname();
+loop1:
+	if((n = read(file,&y,16)) < 16) prname();
+	if(y.jnum != x.inum)goto loop1;
+	close(file);
+	if(y.jnum == 1) ckroot();
+	cat();
+	chdir(dotdot);
+	goto loop0;
+}
+ckroot() {
+	int i, n;
+
+	if((n = stat(y.name,&x)) < 0) prname();
+	i = x.devn;
+	if((n = chdir(root)) < 0) prname();
+	if((file = open(root,0)) < 0) prname();
+loop:
+	if((n = read(file,&y,16)) < 16) prname();
+	if(y.jnum == 0) goto loop;
+	if((n = stat(y.name,&x)) < 0) prname();
+	if(x.devn != i) goto loop;
+	x.i[0] =& 060000;
+	if(x.i[0] != 040000) goto loop;
+	if(y.name[0]=='.')if(((y.name[1]=='.') && (y.name[2]==0)) ||
+				(y.name[1] == 0)) goto pr;
+	cat();
+pr:
+	write(1,root,1);
+	prname();
+}
+prname() {
+	if(off<0)off=0;
+	name[off] = '\n';
+	write(1,name,off+1);
+	exit();
+}
+cat() {
+	int i, j;
+
+	i = -1;
+	while(y.name[++i] != 0);
+	if((off+i+2) > 511) prname();
+	for(j=off+1; j>=0; --j) name[j+i+1] = name[j];
+	off=i+off+1;
+	name[i] = root[0];
+	for(--i; i>=0; --i) name[i] = y.name[i];
+}