log包 常量 Constants 函数列表 func Fatal(v ...interface{}) func Fatalf(format string, v ...interface{}) func Fatalln(v ...interface{}) func Flags() int func Panic(v ...interface{}) func Panicf(format string, v ...interface{}) func Panicln(v ...interface{}) func Prefix() string func Print(v ...interface{}) func Printf(format string, v ...interface{}) func Println(v ...interface{}) func SetFlags(flag int) func SetOutput(w io.Writer) func SetPrefix(prefix string) type Logger func New(out io.Writer, prefix string, flag int) *Logger func (l *Logger) Fatal(v ...interface{}) func (l *Logger) Fatalf(format string, v ...interface{}) func (l *Logger) Fatalln(v ...interface{}) func (l *Logger) Flags() int func (l *Logger) Output(calldepth int, s string) error func (l *Logger) Panic(v ...interface{}) func (l *Logger) Panicf(format string, v ...interface{}) func (l *Logger) Panicln(v ...interface{}) func (l *Logger) Prefix() string func (l *Logger) Print(v ...interface{}) func (l *Logger) Printf(format string, v ...interface{}) func (l *Logger) Println(v ...interface{}) func (l *Logger) SetFlags(flag int) func (l *Logger) SetPrefix(prefix string)