seismograph

small logging utility

seismograph

small node.js debugging utility modeled after node core's debugging technique with log levels and output mechanisms.

$ npm install seismograph

With seismograph you simply invoke the exported function to generate your log function, passing it a name which will determine if a noop function is returned, or a decorated console.error, so all of the console format string goodies you're used to work fine. A unique color is selected per-function for visibility.

Example app.js:

var log = require('seismograph')('http');
var http = require('http');
var name = 'My App';
 
// fake app 
 
log.info('booting %s', name);
 
http.createServer(function(reqres){
  log.info(req.method + ' ' + req.url);
  res.end('hello\n');
}).listen(3000, function(){
  log.info('listening');
});
 
// fake worker of some kind 
 
require('./worker');

Example worker.js:

var log = require('seismograph')('worker');
 
setInterval(function(){
  log.debug('doing some work');
}, 1000);

The DEBUG environment variable is then used to prioritize these based on space or comma-delimited names.

When actively developing an application it can be useful to see when the time spent between one log call and the next. Suppose for example you invoke log.info() before requesting a resource, and after as well, the "+NNNms" will show you how much time was spent between calls.

When stdout is not a TTY, Date#toUTCString() is used by default, making it more useful for logging the debug information.

The * character may be used as a wildcard. Suppose for example your application has debug logs named "worker:login", "worker:logout", "worker:credit", instead of listing all three with DEBUG=worker:login,worker:logout,worker:credit, you may simply do DEBUG=worker:*, or to run everything using this module simply use DEBUG=*.

You can also exclude specific debuggers by prefixing them with a "-" character. For example, DEBUG='* -worker:*' would include all debuggers except those starting with "worker:".

(The MIT License)

Copyright © 2011 TJ Holowaychuk <tj@vision-media.ca> Copyright © 2014 GlobeSherpa

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.