Log Levels

Logly-Zig supports 8 distinct log levels, each with a specific priority, color, and use case.

Level Overview

Level	Priority	Color	ANSI	Method	Alias	Use Case
TRACE	5	Cyan	36	logger.trace()	-	Very detailed debugging
DEBUG	10	Blue	34	logger.debug()	-	Debugging information
INFO	20	White	37	logger.info()	-	General information
SUCCESS	25	Green	32	logger.success()	-	Successful operations
WARNING	30	Yellow	33	logger.warning()	warn()	Warning messages
ERROR	40	Red	31	logger.err()	@"error"()	Error conditions
FAIL	45	Magenta	35	logger.fail()	-	Operation failures
CRITICAL	50	Bright Red	91	logger.critical()	crit()	Critical system errors

Whole-Line Coloring

Logly colors the entire log line (timestamp, level tag, and message), not just the level name:

[2024-01-15 10:30:45] [WARNING] Low disk space    <- Entire line is yellow
[2024-01-15 10:30:46] [ERROR] Connection failed   <- Entire line is red

Usage

// Enable colors on Windows first
_ = logly.Terminal.enableAnsiColors();

// All methods accept optional @src() for clickable file:line output
try logger.trace("Detailed trace information", @src());   // Cyan line
try logger.debug("Debug information", @src());            // Blue line
try logger.info("Application started", @src());           // White line
try logger.success("Operation completed!", @src());       // Green line
try logger.warning("Warning message", @src());            // Yellow line
try logger.warn("Short alias for warning", @src());       // Yellow line (alias)
try logger.err("Error occurred", @src());                 // Red line
try logger.fail("Operation failed", @src());              // Magenta line
try logger.critical("Critical system error!", @src());    // Bright red line
try logger.crit("Short alias for critical", @src());      // Bright red line (alias)

Note: Each level also has a formatted variant (e.g., tracef, infof) that accepts a format string and arguments. See Formatting for details.

Custom Levels

Create your own log levels with custom priorities and colors:

// Add custom levels
try logger.addCustomLevel("audit", 35, "35");      // Magenta (between WARNING and ERR)
try logger.addCustomLevel("notice", 22, "36;1");   // Bold cyan (between INFO and SUCCESS)
try logger.addCustomLevel("alert", 48, "91;1");    // Bold bright red (between FAIL and CRITICAL)

// Use custom levels
try logger.custom("audit", "Security event detected");
try logger.custom("notice", "Important notice");
try logger.customf("alert", "High CPU usage: {d}%", .{95});

Level Filtering

You can configure the minimum log level to output. Messages below this level will be ignored.

var config = logly.Config.default();
config.level = .info; // Ignore TRACE and DEBUG
logger.configure(config);

Module Levels

You can set different log levels for specific modules. This allows you to enable debug logging for a specific part of your application while keeping the rest at a higher level.

// Set global level to INFO
config.level = .info;
logger.configure(config);

// Enable DEBUG for network module
try logger.setModuleLevel("network", .debug);

// Create a scoped logger
const net_logger = logger.scoped("network");
try net_logger.debug("This will be logged");

To use module-specific logging, use the scoped() method to create a logger instance for that module.