api documentation for util (v0.10.3)

Node.JS util module

module util

module util

function util._extend (origin, add)

description and source-code

_extend = function (origin, add) {
  // Don't do anything if add isn't an object
  if (!add || !isObject(add)) return origin;

  var keys = Object.keys(add);
  var i = keys.length;
  while (i--) {
    origin[keys[i]] = add[keys[i]];
  }
  return origin;
}

example usage
```
n/a
```

function util.debuglog (set)

description and source-code

debuglog = function (set) {
  if (isUndefined(debugEnviron))
    debugEnviron = process.env.NODE_DEBUG || '';
  set = set.toUpperCase();
  if (!debugs[set]) {
    if (new RegExp('\\b' + set + '\\b', 'i').test(debugEnviron)) {
      var pid = process.pid;
      debugs[set] = function() {
        var msg = exports.format.apply(exports, arguments);
        console.error('%s %d: %s', set, pid, msg);
      };
    } else {
      debugs[set] = function() {};
    }
  }
  return debugs[set];
}

example usage
```
n/a
```

function util.deprecate (fn, msg)

description and source-code

deprecate = function (fn, msg) {
  // Allow for deprecating things in the process of starting up.
  if (isUndefined(global.process)) {
    return function() {
      return exports.deprecate(fn, msg).apply(this, arguments);
    };
  }

  if (process.noDeprecation === true) {
    return fn;
  }

  var warned = false;
  function deprecated() {
    if (!warned) {
      if (process.throwDeprecation) {
        throw new Error(msg);
      } else if (process.traceDeprecation) {
        console.trace(msg);
      } else {
        console.error(msg);
      }
      warned = true;
    }
    return fn.apply(this, arguments);
  }

  return deprecated;
}

example usage
```
n/a
```

function util.format (f)

description and source-code

format = function (f) {
  if (!isString(f)) {
    var objects = [];
    for (var i = 0; i < arguments.length; i++) {
      objects.push(inspect(arguments[i]));
    }
    return objects.join(' ');
  }

  var i = 1;
  var args = arguments;
  var len = args.length;
  var str = String(f).replace(formatRegExp, function(x) {
    if (x === '%%') return '%';
    if (i >= len) return x;
    switch (x) {
      case '%s': return String(args[i++]);
      case '%d': return Number(args[i++]);
      case '%j':
        try {
          return JSON.stringify(args[i++]);
        } catch (_) {
          return '[Circular]';
        }
      default:
        return x;
    }
  });
  for (var x = args[i]; i < len; x = args[++i]) {
    if (isNull(x) || !isObject(x)) {
      str += ' ' + x;
    } else {
      str += ' ' + inspect(x);
    }
  }
  return str;
}

example usage
```
n/a
```

function util.inherits (ctor, superCtor)

description and source-code

inherits = function (ctor, superCtor) {

  if (ctor === undefined || ctor === null)
    throw new TypeError('The constructor to "inherits" must not be ' +
                        'null or undefined');

  if (superCtor === undefined || superCtor === null)
    throw new TypeError('The super constructor to "inherits" must not ' +
                        'be null or undefined');

  if (superCtor.prototype === undefined)
    throw new TypeError('The super constructor to "inherits" must ' +
                        'have a prototype');

  ctor.super_ = superCtor;
  Object.setPrototypeOf(ctor.prototype, superCtor.prototype);
}

example usage
```
n/a
```

function util.inspect (obj, opts)

description and source-code

function inspect(obj, opts) {
  // default options
  var ctx = {
    seen: [],
    stylize: stylizeNoColor
  };
  // legacy...
  if (arguments.length >= 3) ctx.depth = arguments[2];
  if (arguments.length >= 4) ctx.colors = arguments[3];
  if (isBoolean(opts)) {
    // legacy...
    ctx.showHidden = opts;
  } else if (opts) {
    // got an "options" object
    exports._extend(ctx, opts);
  }
  // set default options
  if (isUndefined(ctx.showHidden)) ctx.showHidden = false;
  if (isUndefined(ctx.depth)) ctx.depth = 2;
  if (isUndefined(ctx.colors)) ctx.colors = false;
  if (isUndefined(ctx.customInspect)) ctx.customInspect = true;
  if (ctx.colors) ctx.stylize = stylizeWithColor;
  return formatValue(ctx, obj, ctx.depth);
}

example usage
```
n/a
```

function util.isArray (ar)

description and source-code

function isArray(ar) {
  return Array.isArray(ar);
}

example usage
```
n/a
```

function util.isBoolean (arg)

description and source-code

function isBoolean(arg) {
  return typeof arg === 'boolean';
}

example usage
```
n/a
```

function util.isBuffer (arg)

description and source-code

function isBuffer(arg) {
  return arg instanceof Buffer;
}

example usage
```
n/a
```

function util.isDate (d)

description and source-code

function isDate(d) {
  return isObject(d) && objectToString(d) === '[object Date]';
}

example usage
```
n/a
```

function util.isError (e)

description and source-code

function isError(e) {
  return isObject(e) &&
      (objectToString(e) === '[object Error]' || e instanceof Error);
}

example usage
```
n/a
```

function util.isFunction (arg)

description and source-code

function isFunction(arg) {
  return typeof arg === 'function';
}

example usage
```
n/a
```

function util.isNull (arg)

description and source-code

function isNull(arg) {
  return arg === null;
}

example usage
```
n/a
```

function util.isNullOrUndefined (arg)

description and source-code

function isNullOrUndefined(arg) {
  return arg == null;
}

example usage
```
n/a
```

function util.isNumber (arg)

description and source-code

function isNumber(arg) {
  return typeof arg === 'number';
}

example usage
```
n/a
```

function util.isObject (arg)

description and source-code

function isObject(arg) {
  return typeof arg === 'object' && arg !== null;
}

example usage
```
n/a
```

function util.isPrimitive (arg)

description and source-code

function isPrimitive(arg) {
  return arg === null ||
         typeof arg === 'boolean' ||
         typeof arg === 'number' ||
         typeof arg === 'string' ||
         typeof arg === 'symbol' ||  // ES6 symbol
         typeof arg === 'undefined';
}

example usage
```
n/a
```

function util.isRegExp (re)

description and source-code

function isRegExp(re) {
  return isObject(re) && objectToString(re) === '[object RegExp]';
}

example usage
```
n/a
```

function util.isString (arg)

description and source-code

function isString(arg) {
  return typeof arg === 'string';
}

example usage
```
n/a
```

function util.isSymbol (arg)

description and source-code

function isSymbol(arg) {
  return typeof arg === 'symbol';
}

example usage
```
n/a
```

function util.isUndefined (arg)

description and source-code

function isUndefined(arg) {
  return arg === void 0;
}

example usage
```
n/a
```

function util.log ()

description and source-code

log = function () {
  console.log('%s - %s', timestamp(), exports.format.apply(exports, arguments));
}

example usage
```
n/a
```

[ this document was created with utility2 ]

api documentation for util (v0.10.3)

Node.JS util module

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