Rename cmd -> examples

examples/mcadump/mcadump.go

@@ -0,0 +1,125 @@
+package main
+
+import (
+	"bytes"
+	"compress/gzip"
+	"compress/zlib"
+	"flag"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+
+	"github.com/Tnze/go-mc/save/region"
+)
+
+var decomp = flag.Bool("x", false, "decompress each chunk to NBT format")
+var repack = flag.Bool("p", false, "repack .mcc file to .mca")
+
+func main() {
+	flag.Usage = usage
+	flag.Parse()
+	args := flag.Args()
+
+	var o string
+	o = "." // output dir
+	if len(args) < 2 {
+		usage()
+	}
+	for _, f := range args[1:] {
+		fs, err := filepath.Glob(f)
+		checkerr(err)
+
+		if *repack {
+			for _, f := range fs {
+				pack(f, o)
+			}
+		} else {
+			for _, f := range fs {
+				unpack(f, o)
+			}
+		}
+	}
+}
+
+func usage() {
+	_, _ = fmt.Fprintf(os.Stderr, "usage: %s [-x] [-r] r.<X>.<Z>.mc{a,c}\n", os.Args[0])
+	os.Exit(1)
+}
+
+// we use this function to check for laziness. Don't scold me >_<
+func checkerr(err error) {
+	if err != nil {
+		_, _ = fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+}
+
+func unpack(f, o string) {
+	var x, z int
+	rn := filepath.Base(f)
+	_, err := fmt.Sscanf(rn, "r.%d.%d.mca", &x, &z)
+	if err != nil {
+		checkerr(fmt.Errorf("cannot use %s as mca file name: %v", rn, err))
+	}
+
+	r, err := region.Open(f)
+	checkerr(err)
+	defer r.Close()
+
+	for i := 0; i < 32; i++ {
+		for j := 0; j < 32; j++ {
+			if !r.ExistSector(i, j) {
+				continue
+			}
+
+			data, err := r.ReadSector(i, j)
+			checkerr(err)
+			var r io.Reader = bytes.NewReader(data[1:])
+
+			fn := fmt.Sprintf("c.%d.%d.mcc", x*32+i, z*32+j)
+			if *decomp {
+				fn += ".nbt" //解压后就是一个标准的NBT文件，可以加个.nbt后缀
+				switch data[0] {
+				default:
+					err = fmt.Errorf("unknown compression type 0x%02x", data[0])
+				case 1:
+					r, err = gzip.NewReader(r)
+				case 2:
+					r, err = zlib.NewReader(r)
+				}
+				checkerr(err)
+			}
+
+			cf, err := os.OpenFile(filepath.Join(o, fn), os.O_CREATE|os.O_RDWR|os.O_EXCL, 0666)
+			checkerr(err)
+
+			_, err = io.Copy(cf, r)
+			checkerr(err)
+		}
+	}
+}
+
+func pack(f, o string) {
+	var x, z int
+	rn := filepath.Base(f)
+	_, err := fmt.Sscanf(rn, "c.%d.%d.mcc", &x, &z)
+	if err != nil {
+		checkerr(fmt.Errorf("cannot use %s as mcc file name: %v", rn, err))
+	}
+
+	fn := fmt.Sprintf("r.%d.%d.mca", x>>5, z>>5)
+	r, err := region.Open(fn)
+	if err != nil && os.IsNotExist(err) {
+		r, err = region.Create(filepath.Join(o, fn))
+	}
+	checkerr(err)
+	defer r.Close()
+
+	mcc, err := os.ReadFile(f)
+	checkerr(err)
+
+	rx, rz := region.In(x, z)
+	err = r.WriteSector(rx, rz, mcc)
+	checkerr(err)
+}