text: // Copyright Joyent, Inc. and other Node contributors.
  //
  // 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.
  
  'use strict';
  
  
  var isWindows = process.platform === 'win32';
  var util = require('util');
  
  
  // resolves . and .. elements in a path array with directory names there
  // must be no slashes or device names (c:\) in the array
  // (so also no leading and trailing slashes - it does not distinguish
  // relative and absolute paths)
  function normalizeArray(parts, allowAboveRoot) {
    var res = [];
    for (var i = 0; i < parts.length; i++) {
      var p = parts[i];
  
      // ignore empty parts
      if (!p || p === '.')
        continue;
  
      if (p === '..') {
        if (res.length && res[res.length - 1] !== '..') {
          res.pop();
        } else if (allowAboveRoot) {
          res.push('..');
        }
      } else {
        res.push(p);
      }
    }
  
    return res;
  }
  
  // returns an array with empty elements removed from either end of the input
  // array or the original array if no elements need to be removed
  function trimArray(arr) {
    var lastIndex = arr.length - 1;
    var start = 0;
    for (; start <= lastIndex; start++) {
      if (arr[start])
        break;
    }
  
    var end = lastIndex;
    for (; end >= 0; end--) {
      if (arr[end])
        break;
    }
  
    if (start === 0 && end === lastIndex)
      return arr;
    if (start > end)
      return [];
    return arr.slice(start, end + 1);
  }
  
  // Regex to split a windows path into three parts: [*, device, slash,
  // tail] windows-only
  var splitDeviceRe =
      /^([a-zA-Z]:|[\\\/]{2}[^\\\/]+[\\\/]+[^\\\/]+)?([\\\/])?([\s\S]*?)$/;
  
  // Regex to split the tail part of the above into [*, dir, basename, ext]
  var splitTailRe =
      /^([\s\S]*?)((?:\.{1,2}|[^\\\/]+?|)(\.[^.\/\\]*|))(?:[\\\/]*)$/;
  
  var win32 = {};
  
  // Function to split a filename into [root, dir, basename, ext]
  function win32SplitPath(filename) {
    // Separate device+slash from tail
    var result = splitDeviceRe.exec(filename),
        device = (result[1] || '') + (result[2] || ''),
        tail = result[3] || '';
    // Split the tail into dir, basename and extension
    var result2 = splitTailRe.exec(tail),
        dir = result2[1],
        basename = result2[2],
        ext = result2[3];
    return [device, dir, basename, ext];
  }
  
  function win32StatPath(path) {
    var result = splitDeviceRe.exec(path),
        device = result[1] || '',
        isUnc = !!device && device[1] !== ':';
    return {
      device: device,
      isUnc: isUnc,
      isAbsolute: isUnc || !!result[2], // UNC paths are always absolute
      tail: result[3]
    };
  }
  
  function normalizeUNCRoot(device) {
    return '\\\\' + device.replace(/^[\\\/]+/, '').replace(/[\\\/]+/g, '\\');
  }
  
  // path.resolve([from ...], to)
  win32.resolve = function() {
    var resolvedDevice = '',
        resolvedTail = '',
        resolvedAbsolute = false;
  
    for (var i = arguments.length - 1; i >= -1; i--) {
      var path;
      if (i >= 0) {
        path = arguments[i];
      } else if (!resolvedDevice) {
        path = process.cwd();
      } else {
        // Windows has the concept of drive-specific current working
        // directories. If we've resolved a drive letter but not yet an
        // absolute path, get cwd for that drive. We're sure the device is not
        // an unc path at this points, because unc paths are always absolute.
        path = process.env['=' + resolvedDevice];
        // Verify that a drive-local cwd was found and that it actually points
        // to our drive. If not, default to the drive's root.
        if (!path || path.substr(0, 3).toLowerCase() !==
            resolvedDevice.toLowerCase() + '\\') {
          path = resolvedDevice + '\\';
        }
      }
  
      // Skip empty and invalid entries
      if (!util.isString(path)) {
        throw new TypeError('Arguments to path.resolve must be strings');
      } else if (!path) {
        continue;
      }
  
      var result = win32StatPath(path),
          device = result.device,
          isUnc = result.isUnc,
          isAbsolute = result.isAbsolute,
          tail = result.tail;
  
      if (device &&
          resolvedDevice &&
          device.toLowerCase() !== resolvedDevice.toLowerCase()) {
        // This path points to another device so it is not applicable
        continue;
      }
  
      if (!resolvedDevice) {
        resolvedDevice = device;
      }
      if (!resolvedAbsolute) {
        resolvedTail = tail + '\\' + resolvedTail;
        resolvedAbsolute = isAbsolute;
      }
  
      if (resolvedDevice && resolvedAbsolute) {
        break;
      }
    }
  
    // Convert slashes to backslashes when `resolvedDevice` points to an UNC
    // root. Also squash multiple slashes into a single one where appropriate.
    if (isUnc) {
      resolvedDevice = normalizeUNCRoot(resolvedDevice);
    }
  
    // At this point the path should be resolved to a full absolute path,
    // but handle relative paths to be safe (might happen when process.cwd()
    // fails)
  
    // Normalize the tail path
    resolvedTail = normalizeArray(resolvedTail.split(/[\\\/]+/),
                                  !resolvedAbsolute).join('\\');
  
    return (resolvedDevice + (resolvedAbsolute ? '\\' : '') + resolvedTail) ||
           '.';
  };
  
  
  win32.normalize = function(path) {
    var result = win32StatPath(path),
        device = result.device,
        isUnc = result.isUnc,
        isAbsolute = result.isAbsolute,
        tail = result.tail,
        trailingSlash = /[\\\/]$/.test(tail);
  
    // Normalize the tail path
    tail = normalizeArray(tail.split(/[\\\/]+/), !isAbsolute).join('\\');
  
    if (!tail && !isAbsolute) {
      tail = '.';
    }
    if (tail && trailingSlash) {
      tail += '\\';
    }
  
    // Convert slashes to backslashes when `device` points to an UNC root.
    // Also squash multiple slashes into a single one where appropriate.
    if (isUnc) {
      device = normalizeUNCRoot(device);
    }
  
    return device + (isAbsolute ? '\\' : '') + tail;
  };
  
  
  win32.isAbsolute = function(path) {
    return win32StatPath(path).isAbsolute;
  };
  
  win32.join = function() {
    var paths = [];
    for (var i = 0; i < arguments.length; i++) {
      var arg = arguments[i];
      if (!util.isString(arg)) {
        throw new TypeError('Arguments to path.join must be strings');
      }
      if (arg) {
        paths.push(arg);
      }
    }
  
    var joined = paths.join('\\');
  
    // Make sure that the joined path doesn't start with two slashes, because
    // normalize() will mistake it for an UNC path then.
    //
    // This step is skipped when it is very clear that the user actually
    // intended to point at an UNC path. This is assumed when the first
    // non-empty string arguments starts with exactly two slashes followed by
    // at least one more non-slash character.
    //
    // Note that for normalize() to treat a path as an UNC path it needs to
    // have at least 2 components, so we don't filter for that here.
    // This means that the user can use join to construct UNC paths from
    // a server name and a share name; for example:
    //   path.join('//server', 'share') -> '\\\\server\\share\')
    if (!/^[\\\/]{2}[^\\\/]/.test(paths[0])) {
      joined = joined.replace(/^[\\\/]{2,}/, '\\');
    }
  
    return win32.normalize(joined);
  };
  
  
  // path.relative(from, to)
  // it will solve the relative path from 'from' to 'to', for instance:
  // from = 'C:\\orandea\\test\\aaa'
  // to = 'C:\\orandea\\impl\\bbb'
  // The output of the function should be: '..\\..\\impl\\bbb'
  win32.relative = function(from, to) {
    from = win32.resolve(from);
    to = win32.resolve(to);
  
    // windows is not case sensitive
    var lowerFrom = from.toLowerCase();
    var lowerTo = to.toLowerCase();
  
    var toParts = trimArray(to.split('\\'));
  
    var lowerFromParts = trimArray(lowerFrom.split('\\'));
    var lowerToParts = trimArray(lowerTo.split('\\'));
  
    var length = Math.min(lowerFromParts.length, lowerToParts.length);
    var samePartsLength = length;
    for (var i = 0; i < length; i++) {
      if (lowerFromParts[i] !== lowerToParts[i]) {
        samePartsLength = i;
        break;
      }
    }
  
    if (samePartsLength == 0) {
      return to;
    }
  
    var outputParts = [];
    for (var i = samePartsLength; i < lowerFromParts.length; i++) {
      outputParts.push('..');
    }
  
    outputParts = outputParts.concat(toParts.slice(samePartsLength));
  
    return outputParts.join('\\');
  };
  
  
  win32._makeLong = function(path) {
    // Note: this will *probably* throw somewhere.
    if (!util.isString(path))
      return path;
  
    if (!path) {
      return '';
    }
  
    var resolvedPath = win32.resolve(path);
  
    if (/^[a-zA-Z]\:\\/.test(resolvedPath)) {
      // path is local filesystem path, which needs to be converted
      // to long UNC path.
      return '\\\\?\\' + resolvedPath;
    } else if (/^\\\\[^?.]/.test(resolvedPath)) {
      // path is network UNC path, which needs to be converted
      // to long UNC path.
      return '\\\\?\\UNC\\' + resolvedPath.substring(2);
    }
  
    return path;
  };
  
  
  win32.dirname = function(path) {
    var result = win32SplitPath(path),
        root = result[0],
        dir = result[1];
  
    if (!root && !dir) {
      // No dirname whatsoever
      return '.';
    }
  
    if (dir) {
      // It has a dirname, strip trailing slash
      dir = dir.substr(0, dir.length - 1);
    }
  
    return root + dir;
  };
  
  
  win32.basename = function(path, ext) {
    var f = win32SplitPath(path)[2];
    // TODO: make this comparison case-insensitive on windows?
    if (ext && f.substr(-1 * ext.length) === ext) {
      f = f.substr(0, f.length - ext.length);
    }
    return f;
  };
  
  
  win32.extname = function(path) {
    return win32SplitPath(path)[3];
  };
  
  
  win32.format = function(pathObject) {
    if (!util.isObject(pathObject)) {
      throw new TypeError(
          "Parameter 'pathObject' must be an object, not " + typeof pathObject
      );
    }
  
    var root = pathObject.root || '';
  
    if (!util.isString(root)) {
      throw new TypeError(
          "'pathObject.root' must be a string or undefined, not " +
          typeof pathObject.root
      );
    }
  
    var dir = pathObject.dir;
    var base = pathObject.base || '';
    if (!dir) {
      return base;
    }
    if (dir[dir.length - 1] === win32.sep) {
      return dir + base;
    }
    return dir + win32.sep + base;
  };
  
  
  win32.parse = function(pathString) {
    if (!util.isString(pathString)) {
      throw new TypeError(
          "Parameter 'pathString' must be a string, not " + typeof pathString
      );
    }
    var allParts = win32SplitPath(pathString);
    if (!allParts || allParts.length !== 4) {
      throw new TypeError("Invalid path '" + pathString + "'");
    }
    return {
      root: allParts[0],
      dir: allParts[0] + allParts[1].slice(0, -1),
      base: allParts[2],
      ext: allParts[3],
      name: allParts[2].slice(0, allParts[2].length - allParts[3].length)
    };
  };
  
  
  win32.sep = '\\';
  win32.delimiter = ';';
  
  
  // Split a filename into [root, dir, basename, ext], unix version
  // 'root' is just a slash, or nothing.
  var splitPathRe =
      /^(\/?|)([\s\S]*?)((?:\.{1,2}|[^\/]+?|)(\.[^.\/]*|))(?:[\/]*)$/;
  var posix = {};
  
  
  function posixSplitPath(filename) {
    return splitPathRe.exec(filename).slice(1);
  }
  
  
  // path.resolve([from ...], to)
  // posix version
  posix.resolve = function() {
    var resolvedPath = '',
        resolvedAbsolute = false;
  
    for (var i = arguments.length - 1; i >= -1 && !resolvedAbsolute; i--) {
      var path = (i >= 0) ? arguments[i] : process.cwd();
  
      // Skip empty and invalid entries
      if (!util.isString(path)) {
        throw new TypeError('Arguments to path.resolve must be strings');
      } else if (!path) {
        continue;
      }
  
      resolvedPath = path + '/' + resolvedPath;
      resolvedAbsolute = path[0] === '/';
    }
  
    // At this point the path should be resolved to a full absolute path, but
    // handle relative paths to be safe (might happen when process.cwd() fails)
  
    // Normalize the path
    resolvedPath = normalizeArray(resolvedPath.split('/'),
                                  !resolvedAbsolute).join('/');
  
    return ((resolvedAbsolute ? '/' : '') + resolvedPath) || '.';
  };
  
  // path.normalize(path)
  // posix version
  posix.normalize = function(path) {
    var isAbsolute = posix.isAbsolute(path),
        trailingSlash = path && path[path.length - 1] === '/';
  
    // Normalize the path
    path = normalizeArray(path.split('/'), !isAbsolute).join('/');
  
    if (!path && !isAbsolute) {
      path = '.';
    }
    if (path && trailingSlash) {
      path += '/';
    }
  
    return (isAbsolute ? '/' : '') + path;
  };
  
  // posix version
  posix.isAbsolute = function(path) {
    return path.charAt(0) === '/';
  };
  
  // posix version
  posix.join = function() {
    var path = '';
    for (var i = 0; i < arguments.length; i++) {
      var segment = arguments[i];
      if (!util.isString(segment)) {
        throw new TypeError('Arguments to path.join must be strings');
      }
      if (segment) {
        if (!path) {
          path += segment;
        } else {
          path += '/' + segment;
        }
      }
    }
    return posix.normalize(path);
  };
  
  
  // path.relative(from, to)
  // posix version
  posix.relative = function(from, to) {
    from = posix.resolve(from).substr(1);
    to = posix.resolve(to).substr(1);
  
    var fromParts = trimArray(from.split('/'));
    var toParts = trimArray(to.split('/'));
  
    var length = Math.min(fromParts.length, toParts.length);
    var samePartsLength = length;
    for (var i = 0; i < length; i++) {
      if (fromParts[i] !== toParts[i]) {
        samePartsLength = i;
        break;
      }
    }
  
    var outputParts = [];
    for (var i = samePartsLength; i < fromParts.length; i++) {
      outputParts.push('..');
    }
  
    outputParts = outputParts.concat(toParts.slice(samePartsLength));
  
    return outputParts.join('/');
  };
  
  
  posix._makeLong = function(path) {
    return path;
  };
  
  
  posix.dirname = function(path) {
    var result = posixSplitPath(path),
        root = result[0],
        dir = result[1];
  
    if (!root && !dir) {
      // No dirname whatsoever
      return '.';
    }
  
    if (dir) {
      // It has a dirname, strip trailing slash
      dir = dir.substr(0, dir.length - 1);
    }
  
    return root + dir;
  };
  
  
  posix.basename = function(path, ext) {
    var f = posixSplitPath(path)[2];
    // TODO: make this comparison case-insensitive on windows?
    if (ext && f.substr(-1 * ext.length) === ext) {
      f = f.substr(0, f.length - ext.length);
    }
    return f;
  };
  
  
  posix.extname = function(path) {
    return posixSplitPath(path)[3];
  };
  
  
  posix.format = function(pathObject) {
    if (!util.isObject(pathObject)) {
      throw new TypeError(
          "Parameter 'pathObject' must be an object, not " + typeof pathObject
      );
    }
  
    var root = pathObject.root || '';
  
    if (!util.isString(root)) {
      throw new TypeError(
          "'pathObject.root' must be a string or undefined, not " +
          typeof pathObject.root
      );
    }
  
    var dir = pathObject.dir ? pathObject.dir + posix.sep : '';
    var base = pathObject.base || '';
    return dir + base;
  };
  
  
  posix.parse = function(pathString) {
    if (!util.isString(pathString)) {
      throw new TypeError(
          "Parameter 'pathString' must be a string, not " + typeof pathString
      );
    }
    var allParts = posixSplitPath(pathString);
    if (!allParts || allParts.length !== 4) {
      throw new TypeError("Invalid path '" + pathString + "'");
    }
    allParts[1] = allParts[1] || '';
    allParts[2] = allParts[2] || '';
    allParts[3] = allParts[3] || '';
  
    return {
      root: allParts[0],
      dir: allParts[0] + allParts[1].slice(0, -1),
      base: allParts[2],
      ext: allParts[3],
      name: allParts[2].slice(0, allParts[2].length - allParts[3].length)
    };
  };
  
  
  posix.sep = '/';
  posix.delimiter = ':';
  
  
  if (isWindows)
    module.exports = win32;
  else /* posix */
    module.exports = posix;
  
  module.exports.posix = posix;
  module.exports.win32 = win32;
  