Added file logger

filelogger.go

@@ -0,0 +1,36 @@
+package slog
+
+import (
+	"fmt"
+	"os"
+	"sync"
+)
+
+type FileLogger struct {
+	w *os.File
+	l sync.Mutex
+}
+
+func (f *FileLogger) Write(p []byte) (n int, err error) {
+	if w == nil {
+		return 0, fmt.Errorf("No file handle available")
+	}
+
+	l.Lock()
+	defer func() {
+		w.Sync()
+		l.Unlock()
+	}()
+
+	return w.Write(p)
+}
+
+func NewFileLogger(file string) (ret io.Writer, err error) {
+	rret := &FileLogger{}
+
+	if rret.w, err = os.OpenFile(file, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644); err != nil {
+		return nil, err
+	}
+
+	return rret
+}