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 = 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 args = arguments;
 84  var useColors = this.useColors;
 85  var name = this.namespace;
 86
 87  if (useColors) {
 88    var c = this.color;
 89
 90    args[0] = '  \u001b[3' + c + ';1m' + name + ' '
 91      + '\u001b[0m'
 92      + args[0] + '\u001b[3' + c + 'm'
 93      + ' +' + exports.humanize(this.diff) + '\u001b[0m';
 94  } else {
 95    args[0] = new Date().toUTCString()
 96      + ' ' + name + ' ' + args[0];
 97  }
 98  return args;
 99}
100
101/**
102 * Invokes `console.error()` with the specified arguments.
103 */
104
105function log() {
106  return stream.write(util.format.apply(this, arguments) + '\n');
107}
108
109/**
110 * Save `namespaces`.
111 *
112 * @param {String} namespaces
113 * @api private
114 */
115
116function save(namespaces) {
117  if (null == namespaces) {
118    // If you set a process.env field to null or undefined, it gets cast to the
119    // string 'null' or 'undefined'. Just delete instead.
120    delete process.env.DEBUG;
121  } else {
122    process.env.DEBUG = namespaces;
123  }
124}
125
126/**
127 * Load `namespaces`.
128 *
129 * @return {String} returns the previously persisted debug modes
130 * @api private
131 */
132
133function load() {
134  return process.env.DEBUG;
135}
136
137/**
138 * Copied from `node/src/node.js`.
139 *
140 * XXX: It's lame that node doesn't expose this API out-of-the-box. It also
141 * relies on the undocumented `tty_wrap.guessHandleType()` which is also lame.
142 */
143
144function createWritableStdioStream (fd) {
145  var stream;
146  var tty_wrap = process.binding('tty_wrap');
147
148  // Note stream._type is used for test-module-load-list.js
149
150  switch (tty_wrap.guessHandleType(fd)) {
151    case 'TTY':
152      stream = new tty.WriteStream(fd);
153      stream._type = 'tty';
154
155      // Hack to have stream not keep the event loop alive.
156      // See https://github.com/joyent/node/issues/1726
157      if (stream._handle && stream._handle.unref) {
158        stream._handle.unref();
159      }
160      break;
161
162    case 'FILE':
163      var fs = require('fs');
164      stream = new fs.SyncWriteStream(fd, { autoClose: false });
165      stream._type = 'fs';
166      break;
167
168    case 'PIPE':
169    case 'TCP':
170      var net = require('net');
171      stream = new net.Socket({
172        fd: fd,
173        readable: false,
174        writable: true
175      });
176
177      // FIXME Should probably have an option in net.Socket to create a
178      // stream from an existing fd which is writable only. But for now
179      // we'll just add this hack and set the `readable` member to false.
180      // Test: ./node test/fixtures/echo.js < /etc/passwd
181      stream.readable = false;
182      stream.read = null;
183      stream._type = 'pipe';
184
185      // FIXME Hack to have stream not keep the event loop alive.
186      // See https://github.com/joyent/node/issues/1726
187      if (stream._handle && stream._handle.unref) {
188        stream._handle.unref();
189      }
190      break;
191
192    default:
193      // Probably an error on in uv_guess_handle()
194      throw new Error('Implement me. Unknown stream file type!');
195  }
196
197  // For supporting legacy API we put the FD here.
198  stream.fd = fd;
199
200  stream._isStdio = true;
201
202  return stream;
203}
204
205/**
206 * Enable namespaces listed in `process.env.DEBUG` initially.
207 */
208
209exports.enable(load());