--- /dev/null
+# debug
+
+ tiny node.js debugging utility modelled after node core's debugging technique.
+
+## Installation
+
+```bash
+$ npm install debug
+```
+
+## Usage
+
+ With `debug` you simply invoke the exported function to generate your debug 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_:
+
+```js
+var debug = require('debug')('http')
+ , http = require('http')
+ , name = 'My App';
+
+// fake app
+
+debug('booting %s', name);
+
+http.createServer(function(req, res){
+ debug(req.method + ' ' + req.url);
+ res.end('hello\n');
+}).listen(3000, function(){
+ debug('listening');
+});
+
+// fake worker of some kind
+
+require('./worker');
+```
+
+Example _worker.js_:
+
+```js
+var debug = require('debug')('worker');
+
+setInterval(function(){
+ debug('doing some work');
+}, 1000);
+```
+
+ The __DEBUG__ environment variable is then used to enable these based on space or comma-delimited names. Here are some examples:
+
+ 
+
+ 
+
+#### Windows note
+
+ On Windows the environment variable is set using the `set` command.
+
+ ```cmd
+ set DEBUG=*,-not_this
+ ```
+
+Then, run the program to be debugged as ususal.
+
+## Millisecond diff
+
+ When actively developing an application it can be useful to see when the time spent between one `debug()` call and the next. Suppose for example you invoke `debug()` 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, making it more useful for logging the debug information as shown below:
+
+ 
+
+## Conventions
+
+ If you're using this in one or more of your libraries, you _should_ use the name of your library so that developers may toggle debugging as desired without guessing names. If you have more than one debuggers you _should_ prefix them with your library name and use ":" to separate features. For example "bodyParser" from Connect would then be "connect:bodyParser".
+
+## Wildcards
+
+ The `*` character may be used as a wildcard. Suppose for example your library has debuggers named "connect:bodyParser", "connect:compress", "connect:session", instead of listing all three with `DEBUG=connect:bodyParser,connect.compress,connect:session`, you may simply do `DEBUG=connect:*`, 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=*,-connect:*` would include all debuggers except those starting with "connect:".
+
+## Browser support
+
+ Debug works in the browser as well, currently persisted by `localStorage`. Consider the situation shown below where you have `worker:a` and `worker:b`, and wish to debug both. Somewhere in the code on your page, include:
+
+```js
+window.myDebug = require("debug");
+```
+
+ ("debug" is a global object in the browser so we give this object a different name.) When your page is open in the browser, type the following in the console:
+
+```js
+myDebug.enable("worker:*")
+```
+
+ Refresh the page. Debug output will continue to be sent to the console until it is disabled by typing `myDebug.disable()` in the console.
+
+```js
+a = debug('worker:a');
+b = debug('worker:b');
+
+setInterval(function(){
+ a('doing some work');
+}, 1000);
+
+setInterval(function(){
+ b('doing some work');
+}, 1200);
+```
+
+#### Web Inspector Colors
+
+ Colors are also enabled on "Web Inspectors" that understand the `%c` formatting
+ option. These are WebKit web inspectors, Firefox ([since version
+ 31](https://hacks.mozilla.org/2014/05/editable-box-model-multiple-selection-sublime-text-keys-much-more-firefox-developer-tools-episode-31/))
+ and the Firebug plugin for Firefox (any version).
+
+ Colored output looks something like:
+
+ 
+
+### stderr vs stdout
+
+You can set an alternative logging method per-namespace by overriding the `log` method on a per-namespace or globally:
+
+Example _stderr.js_:
+
+```js
+var debug = require('../');
+var log = debug('app:log');
+
+// by default console.log is used
+log('goes to stdout!');
+
+var error = debug('app:error');
+// set this namespace to log via console.error
+error.log = console.error.bind(console); // don't forget to bind to console!
+error('goes to stderr');
+log('still goes to stdout!');
+
+// set all output to go via console.warn
+// overrides all per-namespace log settings
+debug.log = console.warn.bind(console);
+log('now goes to stderr via console.warn');
+error('still goes to stderr, but via console.warn now');
+```
+
+## Authors
+
+ - TJ Holowaychuk
+ - Nathan Rajlich
+
+## License
+
+(The MIT License)
+
+Copyright (c) 2014 TJ Holowaychuk <tj@vision-media.ca>
+
+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.
Code Review / sdnc / oam.git / blobdiff