Add original unix v6

source/s1/df.c

@@ -0,0 +1,97 @@
+char	*dargv[]
+{
+	0,
+	"/dev/rk2",
+	"/dev/rp0",
+	0
+};
+struct
+{
+	char	*s_isize;
+	char	*s_fsize;
+	int	s_nfree;
+	int	s_free[100];
+	int	s_ninode;
+	int	s_inode[100];
+	char	s_flock;
+	char	s_ilock;
+	char	s_fmod;
+	int	time[2];
+	int	pad[50];
+} sblock;
+
+int	fi;
+
+main(argc, argv)
+char **argv;
+{
+	int i;
+
+	if(argc <= 1) {
+		for(argc = 1; dargv[argc]; argc++);
+		argv = dargv;
+	}
+
+	for(i=1; i<argc; i++) {
+		if(argc > 1)
+			printf("%s ", argv[i]);
+		dfree(argv[i]);
+	}
+}
+
+dfree(file)
+char *file;
+{
+	int i;
+
+	fi = open(file, 0);
+	if(fi < 0) {
+		printf("cannot open %s\n", file);
+		return;
+	}
+	sync();
+	bread(1, &sblock);
+	i = 0;
+	while(alloc())
+		i++;
+	printf("%l\n", i);
+	close(fi);
+}
+
+alloc()
+{
+	int b, i, buf[256];
+
+	i = --sblock.s_nfree;
+	if(i<0 || i>=100) {
+		printf("bad free count\n");
+		return(0);
+	}
+	b = sblock.s_free[i];
+	if(b == 0)
+		return(0);
+	if(b<sblock.s_isize+2 || b>=sblock.s_fsize) {
+		printf("bad free block (%l)\n", b);
+		return(0);
+	}
+	if(sblock.s_nfree <= 0) {
+		bread(b, buf);
+		sblock.s_nfree = buf[0];
+		for(i=0; i<100; i++)
+			sblock.s_free[i] = buf[i+1];
+	}
+	return(b);
+}
+
+bread(bno, buf)
+{
+	int n;
+	extern errno;
+
+	seek(fi, bno, 3);
+	if((n=read(fi, buf, 512)) != 512) {
+		printf("read error %d\n", bno);
+		printf("count = %d; errno = %d\n", n, errno);
+		exit();
+	}
+}