log: add Logger.Writer method

Writer method returns the underlying io.Writer used by the given Logger
object.

Fixes #28327

Change-Id: I6347913d8be8d3222b98967b136cf03d00f446d1
GitHub-Last-Rev: 2db0c5c7416436f99852592d2f258ca93da96712
GitHub-Pull-Request: golang/go#28399
Reviewed-on: https://go-review.googlesource.com/c/144757
Reviewed-by: Rob Pike <r@golang.org>

diff --git a/src/log/log.go b/src/log/log.go
index 2b7c57fdfe5ffff9904d9dec12958674d34b1a3a..527f853438f08a10bad688b12f7afeddcb0738f1 100644 (file)
--- a/src/log/log.go
+++ b/src/log/log.go
@@ -254,6 +254,13 @@ func (l *Logger) SetPrefix(prefix string) {
        l.prefix = prefix
 }
 
+// Writer returns the output destination for the logger.
+func (l *Logger) Writer() io.Writer {
+       l.mu.Lock()
+       defer l.mu.Unlock()
+       return l.out
+}
+
 // SetOutput sets the output destination for the standard logger.
 func SetOutput(w io.Writer) {
        std.mu.Lock()