Cleanups and improvements.

tee/tee.go

@@ -8,15 +8,19 @@ import (
 // Tee emulates the Unix tee(1) command.
 type Tee struct {
 	f *os.File
+	Verbose bool
 }
 
-func (t *Tee) Write(p []byte) (int64, error) {
+func (t *Tee) Write(p []byte) (int, error) {
 	n, err := os.Stdout.Write(p)
 	if err != nil {
 		return n, err
 	}
 
-	return file.Write(p)
+	if t.f != nil {
+		return t.f.Write(p)
+	}
+	return n, nil
 }
 
 func (t *Tee) Close() error {
@@ -40,9 +44,9 @@ func NewOut(logFile string) (*Tee, error) {
 
 // Printf formats according to a format specifier and writes to the
 // tee instance.
-func (t *Tee) Printf(format string, args ...interface{}) (int64, error) {
+func (t *Tee) Printf(format string, args ...interface{}) (int, error) {
 	s := fmt.Sprintf(format, args...)
-	n, err := os.Stdout.Write(s)
+	n, err := os.Stdout.WriteString(s)
 	if err != nil {
 		return n, err
 	}
@@ -54,6 +58,15 @@ func (t *Tee) Printf(format string, args ...interface{}) (int64, error) {
 	return t.f.WriteString(s)
 }
 
+// VPrintf is a variant of Printf that only prints if the Tee's
+// Verbose flag is set.
+func (t *Tee) VPrintf(format string, args ...interface{}) (int, error) {
+	if t.Verbose {
+		return t.Printf(format, args...)
+	}
+	return 0, nil
+}
+
 var globalTee = &Tee{}
 
 // Open will attempt to open the logFile for the global tee instance.
@@ -63,10 +76,26 @@ func Open(logFile string) error {
 		return err
 	}
 	globalTee.f = f
+	return nil
 }
 
 // Printf formats according to a format specifier and writes to the
 // global tee.
-func Printf(format string, args ...interface{}) (int64, error) {
+func Printf(format string, args ...interface{}) (int, error) {
 	return globalTee.Printf(format, args...)
 }
+
+// VPrintf calls VPrintf on the global tee instance.
+func VPrintf(format string, args ...interface{}) (int, error) {
+	return globalTee.VPrintf(format, args...)
+}
+
+// Close calls close on the global tee instance.
+func Close() error {
+	return globalTee.Close()
+}
+
+// SetVerbose controls the verbosity of the global tee.
+func SetVerbose(verbose bool) {
+	globalTee.Verbose = verbose
+}