tagg2/src/path_resolve.js

full name is threads_a_gogo2,it is a cross platform support, Simple and fast JavaScript threads for Node.js

 (function(){

var normalizeArray = function(parts, allowAboveRoot) {
  // if the path tries to go above the root, `up` ends up > 0
  var up = 0;
  for (var i = parts.length - 1; i >= 0; i--) {
    var last = parts[i];
    if (last === '.') {
      parts.splice(i, 1);
    } else if (last === '..') {
      parts.splice(i, 1);
      up++;
    } else if (up) {
      parts.splice(i, 1);
      up--;
    }
  }

  // if the path is allowed to go above the root, restore leading ..s
  if (allowAboveRoot) {
    for (; up--; up) {
      parts.unshift('..');
    }
  }

  return parts;
}


  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}|[^\\\/]+?|)(\.[^.\/\\]*|))(?:[\\\/]*)$/;


  // path.resolve([from ...], to)
  // windows version
var resolve_win = function(dirname, req_path) {

    //if start with c:\aaa
    if(/^\w(:)(\\)/.test(req_path)) return req_path; 


    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 (typeof path !== 'string') {
        throw new TypeError('Arguments to path.resolve must be strings');
      } else if (!path) {
        continue;
      }

      var result = splitDeviceRe.exec(path),
          device = result[1] || '',
          isUnc = device && device.charAt(1) !== ':',
          isAbsolute = !!result[2] || isUnc, // UNC paths are always absolute
          tail = result[3];

      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

    function f(p) {
      return !!p;
    }

    resolvedTail = normalizeArray(resolvedTail.split(/[\\\/]+/).filter(f),
                                  !resolvedAbsolute).join('\\');

    return (resolvedDevice + (resolvedAbsolute ? '\\' : '') + resolvedTail) ||
           '.';
  };










var resolve_linux = function(dirname, req_path) {

    //if start with /user/
    if(req_path.indexOf('/') === 0) return req_path;

    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 (typeof path !== 'string') {
        throw new TypeError('Arguments to path.resolve must be strings');
      } else if (!path) {
        continue;
      }

      resolvedPath = path + '/' + resolvedPath;
      resolvedAbsolute = path.charAt(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('/').filter(function(p) {
      return !!p;
    }), !resolvedAbsolute).join('/');

    return ((resolvedAbsolute ? '/' : '') + resolvedPath) || '.';
  };



  return {
      "resolve_linux":resolve_linux,
      "resolve_win":resolve_win
  };

  })()