log

Package log implements a simple logging package. It defines a type, Logger, with methods for formatting output. It also has a predefined 'standard' Logger accessible through helper functions Print[f|ln], Fatal[f|ln], and Panic[f|ln], which are easier to use than creating a Logger manually. That logger writes to standard error and prints the date and time of each logged message. Every log message is output on a separate line: if the message being printed does not end in a newline, the logger will add one. The Fatal functions call os.Exit(1) after writing the log message. The Panic functions call panic after writing the log message.

API

    func Fatal(v ...interface{})
    func Fatalf(format string, v ...interface{})
    func Fatalln(v ...interface{})
    func Flags() int
    func Output(calldepth int, s string) error
    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) SetOutput(w io.Writer)
    func (l *Logger) SetPrefix(prefix string)
    func (l *Logger) Writer() io.Writer