Add DialWithDebugOutput to log commands.

debug.go

@@ -0,0 +1,21 @@
+package ftp
+
+import "io"
+
+type debugWrapper struct {
+ conn io.ReadWriteCloser
+ io.Reader
+ io.Writer
+}
+
+func newDebugWrapper(conn io.ReadWriteCloser, w io.Writer) io.ReadWriteCloser {
+ return &debugWrapper{
+ Reader: io.TeeReader(conn, w),
+ Writer: io.MultiWriter(w, conn),
+ conn: conn,
+ }
+}
+
+func (w *debugWrapper) Close() error {
+ return w.conn.Close()
+}

ftp.go

@@ -53,6 +53,7 @@ type dialOptions struct {
  conn net.Conn
  disableEPSV bool
  location *time.Location
+ debugOutput io.Writer
 }
 
 // Entry describes a file and is returned by List().
@@ -100,10 +101,15 @@ func DialWithOptions(addr string, options ...DialOption) (*ServerConn, error) {
  // If we use the domain name, we might not resolve to the same IP.
  remoteAddr := tconn.RemoteAddr().(*net.TCPAddr)
 
+ var sourceConn io.ReadWriteCloser = tconn
+ if do.debugOutput != nil {
+ sourceConn = newDebugWrapper(tconn, do.debugOutput)
+ }
+
  c := &ServerConn{
  options: do,
  features: make(map[string]string),
- conn: textproto.NewConn(tconn),
+ conn: textproto.NewConn(sourceConn),
  host: remoteAddr.IP.String(),
  }
 
@@ -178,6 +184,14 @@ func DialWithTLS(tlsConfig tls.Config) DialOption {
  }}
 }
 
+// DialWithDebugOutput returns a DialOption that configures the ServerConn to write to the Writer
+// everything it reads from the server
+func DialWithDebugOutput(w io.Writer) DialOption {
+ return DialOption{func(do *dialOptions) {
+ do.debugOutput = w
+ }}
+}
+
 // Connect is an alias to Dial, for backward compatibility
 func Connect(addr string) (*ServerConn, error) {
  return Dial(addr)