Because out of all of the existing modules, I couldn't find one that does what I needed and doesn't carry large number of unnecessary dependencies. There are far more complex loggers available, but sometimes all you need is simplicity with specific feature-set.
This module is written in pure ES6 with minimal dependencies.
- Extremely lightweight
- Color coding of different log levels for console output
- Support for console and file logging
- Prefix messages with timestamp
- Maintening configurable ring buffer of past messages
- Automatic expansion of object parameters
- Automatic concating of multiple parameters
- All logging functions are asynchronous for non-blocking operations
Configuration is optional.
If not configured, logging will be to console only and with default format
Configuring inspect options controls how object output is handled
const log = require('pilogger');
const options = {
options.dateFormat: 'YYYY-MM-DD HH:mm:ss',
ringLength: 100,
logFile: './application.log',
accessFile: './accesss.log',
clientFile: './client.log',
inspect: {
showHidden: true,
depth: 5,
colors: true,
showProxy: true,
maxArrayLength: 1024,
maxStringLength: 10240,
breakLength: 200,
compact: 64,
sorted: false,
getters: true,
}
}
log.configure(options);
Messages that are printed to console only, useful for debugging
log.print(...msg);
Messages that are mirrored to console and logFile
(if set), each one prefixed and color coded
log.blank(...msg);
log.data(...msg);
log.state(...msg);
log.info(...msg);
log.warn(...msg);
log.error(...msg);
Example output (note that markdown rules strip colored output):
2020-08-08 10:36:55 INFO: piscan version 0.0.1
2020-08-08 10:36:55 INFO: User: root Platform: linux Arch: x64 Node: v14.4.0
2020-08-08 10:36:55 STATE: Running as root with full capabilities
2020-08-08 10:37:08 DATA: host: pi ip: 192.168.0.100 time: 12,210
2020-08-08 10:37:10 DATA: mac: DC:A6:32:1B:74:D5 vendor: Raspberry Pi os: Linux 5.4
2020-08-08 10:37:12 DATA: ports: 22,139,445,514,873
Messages that are mirrored to console and logFile
(if set), each one prefixed and color coded and with time measurement
const t0 = process.hrtime.bigint();
// do your stuff here
log.timed(t0, ...msg);
Example output:
2020-08-08 10:39:59 TIMED: 1,004 ms Test function execution
Messages that are output to accessFile
(if set) only
Useful for detailed application access log that you don't want printed to console
log.access(...msg);
Messages that are output to clientFile
(if set) only
Useful for logging of any other messages that you don't want printed to console
log.client(...msg);
Access to history ring buffer.
obj.time
is message timestamp, obj.tag
is message type (info, state, data, warn, error), obj.msg
is parsed & concatened message string
for (const line in log.ring) {
console.log(log.ring[line].time, log.ring[line].tag), log.ring[line].msg);
}