std / log

log

import "std:log"

Provides configurable logging with multiple severity levels, output destinations, and formatting options. Includes both a default logger and the ability to create custom Logger instances.

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Index

Types Level Constants NewLogger SetOutput SetLevel SetPrefix LogDebug LogInfo LogWarn LogError LogFatal LogDebugf LogInfof LogWarnf LogErrorf LogFatalf SetDefaultOutput SetDefaultLevel SetDefaultPrefix Debug Info Warn Error Fatal Debugf Infof Warnf Errorf Fatalf ParseLevel LevelFromEnv

Types

# 
type Level int

Represents log message severity.

# 
type Logger struct { /* unexported fields */ }

A configurable logger instance with output stream, minimum level, and prefix.

Level Constants

# 
const (
    LevelDebug Level = iota
    LevelInfo
    LevelWarn
    LevelError
    LevelFatal
)

Log level constants ordered by severity. LevelDebug is the lowest severity and LevelFatal is the highest.

Logger Constructor

# 
func NewLogger(output io.Writer, level Level) Logger

Creates a new logger with the specified output stream and minimum level.

Logger Configuration

# 
func SetOutput(logger *Logger, output io.Writer)

Sets the output stream for the logger.

# 
func SetLevel(logger *Logger, level Level)

Sets the minimum log level for the logger.

# 
func SetPrefix(logger *Logger, prefix string)

Sets the prefix for log messages.

Logger Instance - Simple Logging

# 
func LogDebug(logger *Logger, args ...any)

Logs a debug message.

# 
func LogInfo(logger *Logger, args ...any)

Logs an info message.

# 
func LogWarn(logger *Logger, args ...any)

Logs a warning message.

# 
func LogError(logger *Logger, args ...any)

Logs an error message.

# 
func LogFatal(logger *Logger, args ...any)

Logs a fatal message and exits.

Logger Instance - Printf-style

# 
func LogDebugf(logger *Logger, format string, args ...any)

Logs a formatted debug message.

# 
func LogInfof(logger *Logger, format string, args ...any)

Logs a formatted info message.

# 
func LogWarnf(logger *Logger, format string, args ...any)

Logs a formatted warning message.

# 
func LogErrorf(logger *Logger, format string, args ...any)

Logs a formatted error message.

# 
func LogFatalf(logger *Logger, format string, args ...any)

Logs a formatted fatal message and exits.

Default Logger Configuration

# 
func SetDefaultOutput(output io.Writer)

Sets the output stream for the default logger.

# 
func SetDefaultLevel(level Level)

Sets the minimum log level for the default logger.

# 
func SetDefaultPrefix(prefix string)

Sets the prefix for the default logger.

Default Logger - Simple Logging

# 
func Debug(args ...any)

Logs a debug message to the default logger.

# 
func Info(args ...any)

Logs an info message to the default logger.

# 
func Warn(args ...any)

Logs a warning message to the default logger.

# 
func Error(args ...any)

Logs an error message to the default logger.

# 
func Fatal(args ...any)

Logs a fatal message to the default logger and exits.

Default Logger - Printf-style

# 
func Debugf(format string, args ...any)

Logs a formatted debug message to the default logger.

# 
func Infof(format string, args ...any)

Logs a formatted info message to the default logger.

# 
func Warnf(format string, args ...any)

Logs a formatted warning message to the default logger.

# 
func Errorf(format string, args ...any)

Logs a formatted error message to the default logger.

# 
func Fatalf(format string, args ...any)

Logs a formatted fatal message to the default logger and exits.

Utility

# 
func ParseLevel(s string) Level

Parses a log level from a string. Returns LevelInfo if the string is not recognized.

# 
func LevelFromEnv(envVar string, defaultLevel Level) Level

Reads a log level from an environment variable. Returns defaultLevel if the variable is not set or not recognized.