1  /**
  2   * Module dependencies.
  3   */
  4  
  5  var tty = require('tty');
  6  var util = require('util');
  7  
  8  /**
  9   * This is the Node.js implementation of `debug()`.
 10   *
 11   * Expose `debug()` as the module.
 12   */
 13  
 14  exports = module.exports = require('./debug');
 15  exports.init = init;
 16  exports.log = log;
 17  exports.formatArgs = formatArgs;
 18  exports.save = save;
 19  exports.load = load;
 20  exports.useColors = useColors;
 21  
 22  /**
 23   * Colors.
 24   */
 25  
 26  exports.colors = [6, 2, 3, 4, 5, 1];
 27  
 28  /**
 29   * Build up the default `inspectOpts` object from the environment variables.
 30   *
 31   *   $ DEBUG_COLORS=no DEBUG_DEPTH=10 DEBUG_SHOW_HIDDEN=enabled node script.js
 32   */
 33  
 34  exports.inspectOpts = Object.keys(process.env).filter(function (key) {
 35    return /^debug_/i.test(key);
 36  }).reduce(function (obj, key) {
 37    // camel-case
 38    var prop = key
 39      .substring(6)
 40      .toLowerCase()
 41      .replace(/_([a-z])/g, function (_, k) { return k.toUpperCase() });
 42  
 43    // coerce string value into JS value
 44    var val = process.env[key];
 45    if (/^(yes|on|true|enabled)$/i.test(val)) val = true;
 46    else if (/^(no|off|false|disabled)$/i.test(val)) val = false;
 47    else if (val === 'null') val = null;
 48    else val = Number(val);
 49  
 50    obj[prop] = val;
 51    return obj;
 52  }, {});
 53  
 54  /**
 55   * The file descriptor to write the `debug()` calls to.
 56   * Set the `DEBUG_FD` env variable to override with another value. i.e.:
 57   *
 58   *   $ DEBUG_FD=3 node script.js 3>debug.log
 59   */
 60  
 61  var fd = parseInt(process.env.DEBUG_FD, 10) || 2;
 62  
 63  if (1 !== fd && 2 !== fd) {
 64    util.deprecate(function(){}, 'except for stderr(2) and stdout(1), any other usage of DEBUG_FD is deprecated. Override debug.log if you want to use a different log function (https://git.io/debug_fd)')()
 65  }
 66  
 67  var stream = 1 === fd ? process.stdout :
 68               2 === fd ? process.stderr :
 69               createWritableStdioStream(fd);
 70  
 71  /**
 72   * Is stdout a TTY? Colored output is enabled when `true`.
 73   */
 74  
 75  function useColors() {
 76    return 'colors' in exports.inspectOpts
 77      ? Boolean(exports.inspectOpts.colors)
 78      : tty.isatty(fd);
 79  }
 80  
 81  /**
 82   * Map %o to `util.inspect()`, all on a single line.
 83   */
 84  
 85  exports.formatters.o = function(v) {
 86    this.inspectOpts.colors = this.useColors;
 87    return util.inspect(v, this.inspectOpts)
 88      .split('\n').map(function(str) {
 89        return str.trim()
 90      }).join(' ');
 91  };
 92  
 93  /**
 94   * Map %o to `util.inspect()`, allowing multiple lines if needed.
 95   */
 96  
 97  exports.formatters.O = function(v) {
 98    this.inspectOpts.colors = this.useColors;
 99    return util.inspect(v, this.inspectOpts);
100  };
101  
102  /**
103   * Adds ANSI color escape codes if enabled.
104   *
105   * @api public
106   */
107  
108  function formatArgs(args) {
109    var name = this.namespace;
110    var useColors = this.useColors;
111  
112    if (useColors) {
113      var c = this.color;
114      var prefix = '  \u001b[3' + c + ';1m' + name + ' ' + '\u001b[0m';
115  
116      args[0] = prefix + args[0].split('\n').join('\n' + prefix);
117      args.push('\u001b[3' + c + 'm+' + exports.humanize(this.diff) + '\u001b[0m');
118    } else {
119      args[0] = new Date().toUTCString()
120        + ' ' + name + ' ' + args[0];
121    }
122  }
123  
124  /**
125   * Invokes `util.format()` with the specified arguments and writes to `stream`.
126   */
127  
128  function log() {
129    return stream.write(util.format.apply(util, arguments) + '\n');
130  }
131  
132  /**
133   * Save `namespaces`.
134   *
135   * @param {String} namespaces
136   * @api private
137   */
138  
139  function save(namespaces) {
140    if (null == namespaces) {
141      // If you set a process.env field to null or undefined, it gets cast to the
142      // string 'null' or 'undefined'. Just delete instead.
143      delete process.env.DEBUG;
144    } else {
145      process.env.DEBUG = namespaces;
146    }
147  }
148  
149  /**
150   * Load `namespaces`.
151   *
152   * @return {String} returns the previously persisted debug modes
153   * @api private
154   */
155  
156  function load() {
157    return process.env.DEBUG;
158  }
159  
160  /**
161   * Copied from `node/src/node.js`.
162   *
163   * XXX: It's lame that node doesn't expose this API out-of-the-box. It also
164   * relies on the undocumented `tty_wrap.guessHandleType()` which is also lame.
165   */
166  
167  function createWritableStdioStream (fd) {
168    var stream;
169    var tty_wrap = process.binding('tty_wrap');
170  
171    // Note stream._type is used for test-module-load-list.js
172  
173    switch (tty_wrap.guessHandleType(fd)) {
174      case 'TTY':
175        stream = new tty.WriteStream(fd);
176        stream._type = 'tty';
177  
178        // Hack to have stream not keep the event loop alive.
179        // See https://github.com/joyent/node/issues/1726
180        if (stream._handle && stream._handle.unref) {
181          stream._handle.unref();
182        }
183        break;
184  
185      case 'FILE':
186        var fs = require('fs');
187        stream = new fs.SyncWriteStream(fd, { autoClose: false });
188        stream._type = 'fs';
189        break;
190  
191      case 'PIPE':
192      case 'TCP':
193        var net = require('net');
194        stream = new net.Socket({
195          fd: fd,
196          readable: false,
197          writable: true
198        });
199  
200        // FIXME Should probably have an option in net.Socket to create a
201        // stream from an existing fd which is writable only. But for now
202        // we'll just add this hack and set the `readable` member to false.
203        // Test: ./node test/fixtures/echo.js < /etc/passwd
204        stream.readable = false;
205        stream.read = null;
206        stream._type = 'pipe';
207  
208        // FIXME Hack to have stream not keep the event loop alive.
209        // See https://github.com/joyent/node/issues/1726
210        if (stream._handle && stream._handle.unref) {
211          stream._handle.unref();
212        }
213        break;
214  
215      default:
216        // Probably an error on in uv_guess_handle()
217        throw new Error('Implement me. Unknown stream file type!');
218    }
219  
220    // For supporting legacy API we put the FD here.
221    stream.fd = fd;
222  
223    stream._isStdio = true;
224  
225    return stream;
226  }
227  
228  /**
229   * Init logic for `debug` instances.
230   *
231   * Create a new `inspectOpts` object in case `useColors` is set
232   * differently for a particular `debug` instance.
233   */
234  
235  function init (debug) {
236    debug.inspectOpts = {};
237  
238    var keys = Object.keys(exports.inspectOpts);
239    for (var i = 0; i < keys.length; i++) {
240      debug.inspectOpts[keys[i]] = exports.inspectOpts[keys[i]];
241    }
242  }
243  
244  /**
245   * Enable namespaces listed in `process.env.DEBUG` initially.
246   */
247  
248  exports.enable(load());