package logging import ( `errors` "fmt" "io" `io/fs` "log" "os" `strings` ) // Setup sets up/configures a FileLogger and prepares it for use. func (l *FileLogger) Setup() (err error) { var multi io.Writer // This uses a shared handle across the import. We don't want that. // l.Logger = log.Default() if l.Prefix != "" { l.Prefix = strings.TrimRight(l.Prefix, " ") + " " // l.Logger.SetPrefix(l.Prefix) } if l.writer, err = os.OpenFile(l.Path, appendFlags, logPerm); err != nil { return } // https://stackoverflow.com/a/36719588/733214 switch { case l.EnableStdErr && l.EnableStdOut: multi = io.MultiWriter(os.Stdout, os.Stderr, l.writer) case l.EnableStdErr: multi = io.MultiWriter(os.Stderr, l.writer) case l.EnableStdOut: multi = io.MultiWriter(os.Stdout, l.writer) default: multi = l.writer } l.Logger = log.New(multi, l.Prefix, l.LogFlags) // l.Logger.SetOutput(multi) return } // Shutdown cleanly shuts down a FileLogger. func (l *FileLogger) Shutdown() (err error) { if err = l.writer.Close(); err != nil { if !errors.Is(err, fs.ErrClosed) { return } } return } /* GetPrefix returns the prefix used by this FileLogger. err will always be nil; it's there for interface-compat. */ func (l *FileLogger) GetPrefix() (prefix string, err error) { prefix = l.Prefix return } /* DoDebug sets the debug state of this FileLogger. Note that this merely acts as a *safety filter* for debug messages to avoid sensitive information being written to the log. err will always be nil; it's there for interface-compat. */ func (l *FileLogger) DoDebug(d bool) (err error) { l.EnableDebug = d return } /* SetPrefix sets the prefix for this FileLogger. err will always be nil; it's there for interface-compat. */ func (l *FileLogger) SetPrefix(prefix string) (err error) { l.Prefix = prefix if prefix != "" { l.Prefix = strings.TrimRight(l.Prefix, " ") + " " } l.Logger.SetPrefix(l.Prefix) return } // Alert writes an ALERT-level message to this FileLogger. func (l *FileLogger) Alert(s string, v ...interface{}) (err error) { var msg string if v != nil { msg = fmt.Sprintf(s, v...) } else { msg = s } l.renderWrite(msg, "ALERT") return } // Crit writes an CRITICAL-level message to this FileLogger. func (l *FileLogger) Crit(s string, v ...interface{}) (err error) { var msg string if v != nil { msg = fmt.Sprintf(s, v...) } else { msg = s } l.renderWrite(msg, "CRITICAL") return } // Debug writes a DEBUG-level message to this FileLogger. func (l *FileLogger) Debug(s string, v ...interface{}) (err error) { if !l.EnableDebug { return } var msg string if v != nil { msg = fmt.Sprintf(s, v...) } else { msg = s } l.renderWrite(msg, "DEBUG") return } // Emerg writes an EMERGENCY-level message to this FileLogger. func (l *FileLogger) Emerg(s string, v ...interface{}) (err error) { var msg string if v != nil { msg = fmt.Sprintf(s, v...) } else { msg = s } l.renderWrite(msg, "EMERGENCY") return } // Err writes an ERROR-level message to this FileLogger. func (l *FileLogger) Err(s string, v ...interface{}) (err error) { var msg string if v != nil { msg = fmt.Sprintf(s, v...) } else { msg = s } l.renderWrite(msg, "ERROR") return } // Info writes an INFO-level message to this FileLogger. func (l *FileLogger) Info(s string, v ...interface{}) (err error) { var msg string if v != nil { msg = fmt.Sprintf(s, v...) } else { msg = s } l.renderWrite(msg, "INFO") return } // Notice writes a NOTICE-level message to this FileLogger. func (l *FileLogger) Notice(s string, v ...interface{}) (err error) { var msg string if v != nil { msg = fmt.Sprintf(s, v...) } else { msg = s } l.renderWrite(msg, "NOTICE") return } // Warning writes a WARNING/WARN-level message to this FileLogger. func (l *FileLogger) Warning(s string, v ...interface{}) (err error) { var msg string if v != nil { msg = fmt.Sprintf(s, v...) } else { msg = s } l.renderWrite(msg, "WARNING") return } // renderWrite prepares/formats a log message to be written to this FileLogger. func (l *FileLogger) renderWrite(msg, prio string) { s := fmt.Sprintf("[%v] %v", prio, msg) l.Logger.Println(s) return }