1
  2/**
  3 * Module dependencies.
  4 */
  5
  6var tty = require('tty');
  7var util = require('util');
  8
  9/**
 10 * This is the Node.js implementation of `debug()`.
 11 *
 12 * Expose `debug()` as the module.
 13 */
 14
 15exports = module.exports = require('./debug');
 16exports.log = log;
 17exports.formatArgs = formatArgs;
 18exports.save = save;
 19exports.load = load;
 20exports.useColors = useColors;
 21
 22/**
 23 * Colors.
 24 */
 25
 26exports.colors = [6, 2, 3, 4, 5, 1];
 27
 28/**
 29 * The file descriptor to write the `debug()` calls to.
 30 * Set the `DEBUG_FD` env variable to override with another value. i.e.:
 31 *
 32 *   $ DEBUG_FD=3 node script.js 3>debug.log
 33 */
 34
 35var fd = parseInt(process.env.DEBUG_FD, 10) || 2;
 36var stream = 1 === fd ? process.stdout :
 37             2 === fd ? process.stderr :
 38             createWritableStdioStream(fd);
 39
 40/**
 41 * Is stdout a TTY? Colored output is enabled when `true`.
 42 */
 43
 44function useColors() {
 45  var debugColors = (process.env.DEBUG_COLORS || '').trim().toLowerCase();
 46  if (0 === debugColors.length) {
 47    return tty.isatty(fd);
 48  } else {
 49    return '0' !== debugColors
 50        && 'no' !== debugColors
 51        && 'false' !== debugColors
 52        && 'disabled' !== debugColors;
 53  }
 54}
 55
 56/**
 57 * Map %o to `util.inspect()`, since Node doesn't do that out of the box.
 58 */
 59
 60var inspect = (4 === util.inspect.length ?
 61  // node <= 0.8.x
 62  function (v, colors) {
 63    return util.inspect(v, void 0, void 0, colors);
 64  } :
 65  // node > 0.8.x
 66  function (v, colors) {
 67    return util.inspect(v, { colors: colors });
 68  }
 69);
 70
 71exports.formatters.o = exports.formatters.O = function(v) {
 72  return inspect(v, this.useColors)
 73    .replace(/\s*\n\s*/g, ' ');
 74};
 75
 76/**
 77 * Adds ANSI color escape codes if enabled.
 78 *
 79 * @api public
 80 */
 81
 82function formatArgs() {
 83  var len = arguments.length;
 84  var args = new Array(len);
 85  var useColors = this.useColors;
 86  var name = this.namespace;
 87  for (var i = 0; i < len; i++) {
 88    args[i] = arguments[i];
 89  }
 90
 91  if (useColors) {
 92    var c = this.color;
 93
 94    args[0] = '  \u001b[3' + c + ';1m' + name + ' '
 95      + '\u001b[0m'
 96      + args[0];
 97    args.push('\u001b[3' + c + 'm+' + exports.humanize(this.diff) + '\u001b[0m');
 98  } else {
 99    args[0] = new Date().toUTCString()
100      + ' ' + name + ' ' + args[0];
101  }
102  return args;
103}
104
105/**
106 * Invokes `console.error()` with the specified arguments.
107 */
108
109function log() {
110  return stream.write(util.format.apply(this, arguments) + '\n');
111}
112
113/**
114 * Save `namespaces`.
115 *
116 * @param {String} namespaces
117 * @api private
118 */
119
120function save(namespaces) {
121  if (null == namespaces) {
122    // If you set a process.env field to null or undefined, it gets cast to the
123    // string 'null' or 'undefined'. Just delete instead.
124    delete process.env.DEBUG;
125  } else {
126    process.env.DEBUG = namespaces;
127  }
128}
129
130/**
131 * Load `namespaces`.
132 *
133 * @return {String} returns the previously persisted debug modes
134 * @api private
135 */
136
137function load() {
138  return process.env.DEBUG;
139}
140
141/**
142 * Copied from `node/src/node.js`.
143 *
144 * XXX: It's lame that node doesn't expose this API out-of-the-box. It also
145 * relies on the undocumented `tty_wrap.guessHandleType()` which is also lame.
146 */
147
148function createWritableStdioStream (fd) {
149  var stream;
150  var tty_wrap = process.binding('tty_wrap');
151
152  // Note stream._type is used for test-module-load-list.js
153
154  switch (tty_wrap.guessHandleType(fd)) {
155    case 'TTY':
156      stream = new tty.WriteStream(fd);
157      stream._type = 'tty';
158
159      // Hack to have stream not keep the event loop alive.
160      // See https://github.com/joyent/node/issues/1726
161      if (stream._handle && stream._handle.unref) {
162        stream._handle.unref();
163      }
164      break;
165
166    case 'FILE':
167      var fs = require('fs');
168      stream = new fs.SyncWriteStream(fd, { autoClose: false });
169      stream._type = 'fs';
170      break;
171
172    case 'PIPE':
173    case 'TCP':
174      var net = require('net');
175      stream = new net.Socket({
176        fd: fd,
177        readable: false,
178        writable: true
179      });
180
181      // FIXME Should probably have an option in net.Socket to create a
182      // stream from an existing fd which is writable only. But for now
183      // we'll just add this hack and set the `readable` member to false.
184      // Test: ./node test/fixtures/echo.js < /etc/passwd
185      stream.readable = false;
186      stream.read = null;
187      stream._type = 'pipe';
188
189      // FIXME Hack to have stream not keep the event loop alive.
190      // See https://github.com/joyent/node/issues/1726
191      if (stream._handle && stream._handle.unref) {
192        stream._handle.unref();
193      }
194      break;
195
196    default:
197      // Probably an error on in uv_guess_handle()
198      throw new Error('Implement me. Unknown stream file type!');
199  }
200
201  // For supporting legacy API we put the FD here.
202  stream.fd = fd;
203
204  stream._isStdio = true;
205
206  return stream;
207}
208
209/**
210 * Enable namespaces listed in `process.env.DEBUG` initially.
211 */
212
213exports.enable(load());