commit 25ee8653263059b97e75154e37ac8b3b9483c38a
Author: Knut Ahlers <knut@ahlers.me>
Date:   Mon Oct 10 16:50:27 2016 +0200

    Initial working version

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..2202574
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+.env
+dbx-sync
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..bb53cc3
--- /dev/null
+++ b/main.go
@@ -0,0 +1,152 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"path"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"github.com/Luzifer/rconfig"
+	"github.com/dropbox/dropbox-sdk-go-unofficial/dropbox"
+	"github.com/dropbox/dropbox-sdk-go-unofficial/dropbox/files"
+)
+
+var (
+	cfg = struct {
+		DropboxToken   string `flag:"dropbox-token" env:"DROPBOX_TOKEN" description:"Dropbox token to use to access API"`
+		ForceOverwrite bool   `flag:"force-overwrite" default:"false" description:"Upload files even when they exist on target"`
+		Verbose        bool   `flag:"verbose,v" default:"false" description:"Enable verbose logging"`
+		VersionAndExit bool   `flag:"version" default:"false" description:"Prints current version and exits"`
+	}{}
+
+	version = "dev"
+)
+
+func init() {
+	if err := rconfig.Parse(&cfg); err != nil {
+		log.Fatalf("Unable to parse commandline options: %s", err)
+	}
+
+	if cfg.VersionAndExit {
+		fmt.Printf("dbx-sync %s\n", version)
+		os.Exit(0)
+	}
+}
+
+func main() {
+	if len(rconfig.Args()) != 3 {
+		log.Fatalf("Usage: dbx-sync <source path> <destination prefix>")
+	}
+
+	sourcePath := rconfig.Args()[1]
+	destPrefix := rconfig.Args()[2]
+
+	if f, err := os.Stat(sourcePath); err != nil || !f.IsDir() {
+		log.Fatalf("Source path %q does not exist or is not a directory.", sourcePath)
+	}
+
+	if destPrefix[0] != '/' {
+		log.Fatalf("Destination prefix must start with '/': %q", destPrefix)
+	}
+
+	config := dropbox.Config{Token: cfg.DropboxToken, Verbose: cfg.Verbose}
+	dbx := files.New(config)
+
+	remoteFilesPresent, err := getRemoteFileList(dbx, rconfig.Args()[2])
+	if err != nil {
+		log.Fatalf("Error while doing getRemoteFileList request: %s", err)
+	}
+
+	localFilesPresent, err := getLocalFileList(rconfig.Args()[1])
+	if err != nil {
+		log.Fatalf("Error while reading local file list: %s", err)
+	}
+
+	for f, lmt := range localFilesPresent {
+		dest := path.Join(destPrefix, strings.Replace(f, sourcePath, "", -1))
+		if rmt, ok := remoteFilesPresent[dest]; ok && !cfg.ForceOverwrite && !rmt.Before(lmt) {
+			if cfg.Verbose {
+				log.Printf("Remote %q already there, not uploading.", dest)
+			}
+			continue
+		}
+
+		log.Printf("Uploading %q to %q", f, dest)
+		if err := uploadFile(dbx, f, dest); err != nil {
+			log.Fatalf("Error while uploading %q: %s", dest, err)
+		}
+	}
+
+}
+
+func uploadFile(dbx files.Client, sourceFile, destinationFile string) error {
+	info, err := os.Stat(sourceFile)
+	if err != nil {
+		return err
+	}
+
+	content, err := os.Open(sourceFile)
+	if err != nil {
+		return err
+	}
+	defer content.Close()
+
+	modTime := time.Unix(info.ModTime().Unix(), 0)
+
+	writeMode := &files.WriteMode{}
+	writeMode.Tag = files.WriteModeOverwrite
+
+	_, err = dbx.Upload(&files.CommitInfo{
+		Path:           destinationFile,
+		Mode:           writeMode,
+		ClientModified: modTime,
+	}, content)
+	return err
+}
+
+func getRemoteFileList(dbx files.Client, prefix string) (map[string]time.Time, error) {
+	remoteFilesPresent := map[string]time.Time{}
+
+	lfr, err := dbx.ListFolder(&files.ListFolderArg{
+		Path:      prefix,
+		Recursive: true,
+	})
+	if err != nil {
+		if strings.Contains(err.Error(), "path/not_found/") {
+			return remoteFilesPresent, nil
+		}
+		return remoteFilesPresent, err
+	}
+	for {
+		for _, f := range lfr.Entries {
+			if fm, ok := f.(*files.FileMetadata); ok {
+				remoteFilesPresent[fm.PathDisplay] = fm.ClientModified
+			}
+		}
+
+		if !lfr.HasMore {
+			break
+		}
+
+		lfr, err = dbx.ListFolderContinue(&files.ListFolderContinueArg{Cursor: lfr.Cursor})
+		if err != nil {
+			return remoteFilesPresent, err
+		}
+	}
+
+	return remoteFilesPresent, nil
+}
+
+func getLocalFileList(prefix string) (map[string]time.Time, error) {
+	fileList := map[string]time.Time{}
+
+	return fileList, filepath.Walk(prefix, func(path string, f os.FileInfo, err error) error {
+		if !f.IsDir() {
+			fileList[path] = f.ModTime()
+		}
+		return nil
+	})
+}