in glog.go [829:852]
func (sb *syncBuffer) rotateFile(now time.Time) error {
if sb.file != nil {
sb.Flush()
sb.file.Close()
}
var err error
sb.file, _, err = create(severityName[sb.sev], now)
sb.nbytes = 0
if err != nil {
return err
}
sb.Writer = bufio.NewWriterSize(sb.file, bufferSize)
// Write header.
var buf bytes.Buffer
fmt.Fprintf(&buf, "Log file created at: %s\n", now.Format("2006/01/02 15:04:05"))
fmt.Fprintf(&buf, "Running on machine: %s\n", host)
fmt.Fprintf(&buf, "Binary: Built with %s %s for %s/%s\n", runtime.Compiler, runtime.Version(), runtime.GOOS, runtime.GOARCH)
fmt.Fprintf(&buf, "Log line format: [IWEF]mmdd hh:mm:ss.uuuuuu threadid file:line] msg\n")
n, err := sb.file.Write(buf.Bytes())
sb.nbytes += uint64(n)
return err
}