Merge pull request #37 from barasher/35_binaryLocation

Windows support (exiftool binary location)

exiftool.go

@@ -13,7 +13,6 @@ import (
 	"errors"
 )
 
-var binary = "exiftool"
 var executeArg = "-execute"
 var initArgs = []string{"-stay_open", "True", "-@", "-", "-common_args"}
 var extractArgs = []string{"-j"}
@@ -25,20 +24,23 @@ var ErrNotExist = errors.New("file does not exist")
 
 // Exiftool is the exiftool utility wrapper
 type Exiftool struct {
-	lock          sync.Mutex
-	stdin         io.WriteCloser
-	stdMergedOut  io.ReadCloser
-	scanMergedOut *bufio.Scanner
-	bufferSet     bool
-	buffer        []byte
-	bufferMaxSize int
-	extraInitArgs []string
+	lock            sync.Mutex
+	stdin           io.WriteCloser
+	stdMergedOut    io.ReadCloser
+	scanMergedOut   *bufio.Scanner
+	bufferSet       bool
+	buffer          []byte
+	bufferMaxSize   int
+	extraInitArgs   []string
+	exiftoolBinPath string
 }
 
 // NewExiftool instanciates a new Exiftool with configuration functions. If anything went
 // wrong, a non empty error will be returned.
 func NewExiftool(opts ...func(*Exiftool) error) (*Exiftool, error) {
-	e := Exiftool{}
+	e := Exiftool{
+		exiftoolBinPath: exiftoolBinary,
+	}
 
 	for _, opt := range opts {
 		if err := opt(&e); err != nil {
@@ -47,7 +49,7 @@ func NewExiftool(opts ...func(*Exiftool) error) (*Exiftool, error) {
 	}
 
 	args := append(initArgs, e.extraInitArgs...)
-	cmd := exec.Command(binary, args...)
+	cmd := exec.Command(e.exiftoolBinPath, args...)
 	r, w := io.Pipe()
 	e.stdMergedOut = r
 
@@ -215,3 +217,16 @@ func ExtractAllBinaryMetadata() func(*Exiftool) error {
 		return nil
 	}
 }
+
+// SetExiftoolBinaryPath sets exiftool's binary path. When not specified, the binary will have to be in $PATH
+// Sample :
+//   e, err := NewExiftool(SetExiftoolBinaryPath("/usr/bin/exiftool"))
+func SetExiftoolBinaryPath(p string) func(*Exiftool) error {
+	return func(e *Exiftool) error {
+		if _, err := os.Stat(p); err != nil {
+			return fmt.Errorf("error while checking if path '%v' exists: %w", p, err)
+		}
+		e.exiftoolBinPath = p
+		return nil
+	}
+}

exiftool_test.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"strings"
 	"testing"
+	"os/exec"
 
 	"github.com/stretchr/testify/assert"
 )
@@ -296,3 +297,29 @@ func TestExtractAllBinaryMetadata(t *testing.T) {
 	assert.Nil(t, err)
 	assert.True(t, strings.HasPrefix(osn, "base64"))
 }
+
+func TestSetExiftoolBinaryPath(t *testing.T) {
+	// default
+	eDefault, err := NewExiftool()
+	assert.Nil(t, err)
+	defer eDefault.Close()
+	f := eDefault.ExtractMetadata("./testdata/20190404_131804.jpg")
+	assert.Equal(t, 1, len(f))
+	assert.Nil(t, f[0].Err)
+
+	// set path
+	exiftoolPath, err := exec.LookPath(exiftoolBinary)
+	assert.Nil(t, err)
+	t.Logf("exiftool path: %v", exiftoolPath)
+	eSet, err := NewExiftool(SetExiftoolBinaryPath(exiftoolPath))
+	assert.Nil(t, err)
+	defer eSet.Close()
+	f = eSet.ExtractMetadata("./testdata/20190404_131804.jpg")
+	assert.Equal(t, 1, len(f))
+	assert.Nil(t, f[0].Err)
+
+	// error on init
+	_, err = NewExiftool(SetExiftoolBinaryPath("/non/existing/path"))
+	assert.NotNil(t, err)
+
+}

platform_darwin.go

@@ -1,3 +1,4 @@
 package exiftool
 
 var readyToken = []byte("{ready}\n")
+var exiftoolBinary = "exiftool"

platform_freebsd.go

@@ -1,3 +1,4 @@
 package exiftool
 
 var readyToken = []byte("{ready}\n")
+var exiftoolBinary = "exiftool"

platform_linux.go

@@ -1,3 +1,4 @@
 package exiftool
 
 var readyToken = []byte("{ready}\n")
+var exiftoolBinary = "exiftool"

platform_windows.go

@@ -1,3 +1,4 @@
 package exiftool
 
 var readyToken = []byte("{ready}\r\n")
+var exiftoolBinary = "exiftool.exe"