Caterpillar is the ultimate logging system for Node.js, based on transform streams you can log to it and pipe the output off to different locations, including some pre-made ones. Caterpillar also supports log levels according to the RFC standard, as well as line, method, and file fetching for messages. You can even use it in web browsers with the Browser Transform.
- Use:
require('caterpillar')
- Install:
npm install --save caterpillar
- Use:
require('caterpillar')
- Install:
npm install --save caterpillar
- CDN URL:
//wzrd.in/bundle/caterpillar@2.0.7
- Use:
require('caterpillar')
- Install:
ender add caterpillar
// Import
var level = process.argv.indexOf('-d') === -1 ? 6 : 7;
var logger = require('caterpillar').createLogger({level:level});
var filter = require('caterpillar-filter').createFilter();
var human = require('caterpillar-human').createHuman();
// Where to output?
if ( process.title === 'browser' ) {
// Include the browser compatibility layer
var browser = require('caterpillar-browser').createBrowser();
// Pipe to filter to human to browser
logger.pipe(filter).pipe(human).pipe(browser);
}
else {
// Pipe to filter to human to stdout
logger.pipe(filter).pipe(human).pipe(process.stdout);
// If we are debugging, then write the original logger data to debug.log
if ( level === 7 ) {
logger.pipe(require('fs').createWriteStream('./debug.log'));
}
}
// Log messages
logger.log('emergency', 'this is level 0');
logger.log('emerg', 'this is level 0');
logger.log('alert', 'this is level 1');
logger.log('critical', 'this is level 2');
logger.log('crit', 'this is level 2');
logger.log('error', 'this is level 3');
logger.log('err', 'this is level 3');
logger.log('warning', 'this is level 4');
logger.log('warn', 'this is level 4');
logger.log('notice', 'this is level 5');
logger.log('note', 'this is level 5');
logger.log('info', 'this is level 6');
logger.log('default', 'this is level 6');
logger.log('debug', 'this is level 7');
logger.log('this is level 6, the default level');
logger.log('you','can','also','use','as','many','arguments','as','you','want',1,[2,3],{four:5});
Result with log level 6 (info):
Result with log level 7 (debug):
Result with log level 7 (debug) in the browser with the Browser Transform
Transform API, extends stream.Transform
new (require('caterpillar').Transform)(config)
- Methods
constructor(config?)
create our new instance with the config, config is optionalpipe(child)
pipe our stream to the child, also sync our config to itsetConfig(config)
set the configuration and emit theconfig
eventgetConfig()
get the configurationformat(entry)
format the caterpillar logger entry
- Configuration
- none by default
- Events
config(config)
emitted once our configuration has updated
new (require('caterpillar').Logger)(config)
-
Methods
-
constructor(config?)
create our new instance with the config, config is optional -
log(args...)
write a log message, the first argument is suppose to be the level (will use the default level if it isn't) -
format(level, args...)
create a log entry ready for writing to the logger stream, output is as follows:{ "args": ["this is emergency and is level 0"], "date": "2013-04-25T10:18:25.722Z", "levelNumber": 0, "levelName": "emergency", "line": "59", "method": "Task.fn", "file": "/Users/balupton/Projects/caterpillar/out/test/caterpillar-test.js" }
-
getLevelNumber(name)
get the level number for the level name -
getLevelName(number)
get the level name for the level number -
getLevelInfo(nameOrNumber)
get the level name and number for either a level name or number -
getLineInfo()
get the file, method, and line that thelog
method was called on
-
-
Configuration
-
lineOffset
the amount of lines to offset when doing our line detection, useful for wrappers, defaults to0
-
levels
the level names and their associated number, also includesdefault
for when no level was specified, defaults to:{ emergency: 0, alert: 1, critical: 2, error: 3, warning: 4, notice: 5, info: 6, debug: 7, emerg: 0, crit: 2, err: 3, warn: 4, note: 5, default: 6 }
-
-
Events
- only those inherited
Discover the change history by heading on over to the HISTORY.md
file.
These amazing people are maintaining this project:
- Benjamin Lupton b@lupton.cc (https://github.com/balupton)
No sponsors yet! Will you be the first?
These amazing people have contributed code to this project:
- Benjamin Lupton b@lupton.cc (https://github.com/balupton) - view contributions
- t-visualappeal (https://github.com/t-visualappeal) - view contributions
Licensed under the incredibly permissive MIT license
Copyright © 2012+ Bevry Pty Ltd us@bevry.me (http://bevry.me)
Copyright © 2011 Benjamin Lupton b@lupton.cc (http://balupton.com)