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Merge stdout and stderr to see errors easier #8

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Merged
barasher merged 1 commit into from
Aug 16, 2020
Merged

Merge stdout and stderr to see errors easier #8

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37 changes: 19 additions & 18 deletions exiftool.go
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Original file line number Diff line number Diff line change
Expand Up @@ -26,10 +26,10 @@ var ErrNotExist = errors.New("file does not exist")

// Exiftool is the exiftool utility wrapper
type Exiftool struct {
lock sync.Mutex
stdin io.WriteCloser
stdout io.ReadCloser
scanout *bufio.Scanner
lock sync.Mutex
stdin io.WriteCloser
stdMergedOut io.ReadCloser
scanMergedOut *bufio.Scanner
}

// NewExiftool instanciates a new Exiftool with configuration functions. If anything went
Expand All @@ -44,18 +44,19 @@ func NewExiftool(opts ...func(*Exiftool) error) (*Exiftool, error) {
}

cmd := exec.Command(binary, initArgs...)
r, w := io.Pipe()
e.stdMergedOut = r

cmd.Stdout = w
cmd.Stderr = w

var err error
if e.stdin, err = cmd.StdinPipe(); err != nil {
return nil, fmt.Errorf("error when piping stdin: %w", err)
}

if e.stdout, err = cmd.StdoutPipe(); err != nil {
return nil, fmt.Errorf("error when piping stdout: %w", err)
}

e.scanout = bufio.NewScanner(e.stdout)
e.scanout.Split(splitReadyToken)
e.scanMergedOut = bufio.NewScanner(r)
e.scanMergedOut.Split(splitReadyToken)

if err = cmd.Start(); err != nil {
return nil, fmt.Errorf("error when executing commande: %w", err)
Expand All @@ -77,8 +78,8 @@ func (e *Exiftool) Close() error {
}

var errs []error
if err := e.stdout.Close(); err != nil {
errs = append(errs, fmt.Errorf("error while closing stdout: %w", err))
if err := e.stdMergedOut.Close(); err != nil {
errs = append(errs, fmt.Errorf("error while closing stdMergedOut: %w", err))
}

if err := e.stdin.Close(); err != nil {
Expand Down Expand Up @@ -120,19 +121,19 @@ func (e *Exiftool) ExtractMetadata(files ...string) []FileMetadata {
fmt.Fprintln(e.stdin, f)
fmt.Fprintln(e.stdin, executeArg)

if !e.scanout.Scan() {
fms[i].Err = fmt.Errorf("nothing on stdout")
if !e.scanMergedOut.Scan() {
fms[i].Err = fmt.Errorf("nothing on stdMergedOut")
continue
}

if e.scanout.Err() != nil {
fms[i].Err = fmt.Errorf("error while reading stdout: %w", e.scanout.Err())
if e.scanMergedOut.Err() != nil {
fms[i].Err = fmt.Errorf("error while reading stdMergedOut: %w", e.scanMergedOut.Err())
continue
}

var m []map[string]interface{}
if err := json.Unmarshal(e.scanout.Bytes(), &m); err != nil {
fms[i].Err = fmt.Errorf("error during unmarshaling (%v): %w)", e.scanout.Bytes(), err)
if err := json.Unmarshal(e.scanMergedOut.Bytes(), &m); err != nil {
fms[i].Err = fmt.Errorf("error during unmarshaling (%v): %w)", e.scanMergedOut.Bytes(), err)
continue
}

Expand Down
6 changes: 3 additions & 3 deletions exiftool_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -137,7 +137,7 @@ func TestCloseNominal(t *testing.T) {

r := readWriteCloserMock{closed: &rClosed}
w := readWriteCloserMock{closed: &wClosed}
e := Exiftool{stdin: r, stdout: w}
e := Exiftool{stdin: r, stdMergedOut: w}

assert.Nil(t, e.Close())
assert.True(t, rClosed)
Expand All @@ -149,7 +149,7 @@ func TestCloseErrorOnStdin(t *testing.T) {

r := readWriteCloserMock{closed: &rClosed, closeErr: fmt.Errorf("error")}
w := readWriteCloserMock{closed: &wClosed}
e := Exiftool{stdin: r, stdout: w}
e := Exiftool{stdin: r, stdMergedOut: w}

assert.NotNil(t, e.Close())
assert.True(t, rClosed)
Expand All @@ -161,7 +161,7 @@ func TestCloseErrorOnStdout(t *testing.T) {

r := readWriteCloserMock{closed: &rClosed}
w := readWriteCloserMock{closed: &wClosed, closeErr: fmt.Errorf("error")}
e := Exiftool{stdin: r, stdout: w}
e := Exiftool{stdin: r, stdMergedOut: w}

assert.NotNil(t, e.Close())
assert.True(t, rClosed)
Expand Down