Initial Commit. Seems to work

.gitignore

@@ -0,0 +1,2 @@
+# Ignore the binary
+jpg-metadata

main.go

@@ -0,0 +1,118 @@
+package main
+
+import (
+	"errors"
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"strings"
+
+	"github.com/rwcarlsen/goexif/exif"
+)
+
+var inJson bool
+var filename string
+
+func init() {
+	const (
+		filenameUsage = "The File/Directory to scan"
+		inJsonDefault = false
+		inJsonUsage   = "Output the result in JSON"
+	)
+	flag.StringVar(&filename, "filename", "", filenameUsage)
+	flag.BoolVar(&inJson, "json", inJsonDefault, inJsonUsage)
+}
+
+func main() {
+	flag.Parse()
+
+	fInfo, err := os.Lstat(filename)
+	if err != nil {
+		fmt.Println("Error reading passed file/directory")
+		os.Exit(1)
+	}
+	if fInfo.IsDir() {
+		ProcessDirectory(filename, inJson)
+	} else {
+		PrintJpegData(filename, inJson)
+	}
+}
+
+func ProcessDirectory(dirname string, inJson bool) {
+	if !inJson {
+		fmt.Println("Reading Directory:", dirname)
+	}
+	files, err := ioutil.ReadDir(dirname)
+	if err != nil {
+		panic(err)
+	}
+
+	if !strings.HasSuffix(dirname, "/") {
+		dirname += "/"
+	}
+
+	if inJson {
+		fmt.Print("[")
+	}
+	foundFirst := false
+	for _, file := range files {
+		if isJpeg(dirname+file.Name()) && inJson && foundFirst {
+			fmt.Print(",")
+		}
+		if PrintJpegData(dirname+file.Name(), inJson) == nil {
+			foundFirst = true
+			if !inJson {
+				fmt.Println("")
+			}
+		}
+	}
+	if inJson {
+		fmt.Print("]")
+	}
+}
+
+func isJpeg(filename string) bool {
+	nm := strings.ToUpper(filename)
+	return strings.HasSuffix(nm, ".JPG") || strings.HasSuffix(nm, ".JPEG")
+}
+
+func PrintJpegData(filename string, inJson bool) error {
+	if !isJpeg(filename) {
+		return errors.New("Not a JPEG")
+	}
+	exif, err := ReadExifData(filename)
+	if err != nil {
+		if !inJson {
+			fmt.Println("Error: " + err.Error())
+			return err
+		}
+	}
+	if inJson {
+		fmt.Print("{\"Filename\":\"" + filename + "\",\"Exif\":")
+		if exif == nil {
+			fmt.Print("{}")
+		} else {
+			json, err := exif.MarshalJSON()
+			if err != nil {
+				fmt.Print("{}")
+			}
+			fmt.Print(string(json))
+		}
+		fmt.Print("}")
+	} else {
+		fmt.Println("= " + filename + " =")
+		fmt.Println(exif)
+	}
+	return nil
+}
+
+func ReadExifData(filename string) (*exif.Exif, error) {
+	f, err := os.Open(filename)
+	if err != nil {
+		fmt.Println("Error:", err.Error())
+		return &exif.Exif{}, err
+	}
+	defer f.Close()
+	return exif.Decode(f)
+}