log

.zn module

Structured, leveled logging to stderr. import "log". A Logger holds a name and a minimum level; messages below the level are dropped. Output format: [LEVEL] [name] message. Levels: log.LEVEL_DEBUG (0), LEVEL_INFO (1), LEVEL_WARN (2), LEVEL_ERROR (3), LEVEL_FATAL (4), LEVEL_OFF (5).

log.new(name: string) => Logger
log.set_level(logger, level: int)
log.format_line(logger, level: int, msg) => string
log.debug/info/warn/error(logger, msg: string)
log.fatal(logger, msg: string)
log.debugf/infof/warnf/errorf(logger, msg, fields: [string, string])
log.fatalf(logger, msg, fields)

log.new(name: string) => Logger

Create a logger (default level INFO).

log.set_level(logger, level: int)

Set the minimum level.

log.format_line(logger, level: int, msg) => string

Build the formatted line (no I/O).

log.debug/info/warn/error(logger, msg: string)

Log at that level.

log.fatal(logger, msg: string)

Log at FATAL, then os.exit(1).

log.debugf/infof/warnf/errorf(logger, msg, fields: [string, string])

Log with key=value structured fields appended.

log.fatalf(logger, msg, fields)

Structured FATAL, then os.exit(1).

import "log"
lg := log.new("myapp")
log.set_level(lg, log.LEVEL_DEBUG)
log.info(lg, "server ready")
log.infof(lg, "request", {"method": "GET", "path": "/api"})

log