// 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.
var pathModule = require('path');
var isWindows = process.platform === 'win32';
var fs = require('fs');
// JavaScript implementation of realpath, ported from node pre-v6
var DEBUG = process.env.NODE_DEBUG && /fs/.test(process.env.NODE_DEBUG);
function rethrow() {
// Only enable in debug mode. A backtrace uses ~1000 bytes of heap space and
// is fairly slow to generate.
var callback;
if (DEBUG) {
var backtrace = new Error;
callback = debugCallback;
} else
callback = missingCallback;
return callback;
function debugCallback(err) {
if (err) {
backtrace.message = err.message;
err = backtrace;
missingCallback(err);
}
}
function missingCallback(err) {
if (err) {
if (process.throwDeprecation)
throw err; // Forgot a callback but don't know where? Use NODE_DEBUG=fs
else if (!process.noDeprecation) {
var msg = 'fs: missing callback ' + (err.stack || err.message);
if (process.traceDeprecation)
console.trace(msg);
else
console.error(msg);
}
}
}
}
function maybeCallback(cb) {
return typeof cb === 'function' ? cb : rethrow();
}
var normalize = pathModule.normalize;
// Regexp that finds the next partion of a (partial) path
// result is [base_with_slash, base], e.g. ['somedir/', 'somedir']
if (isWindows) {
var nextPartRe = /(.*?)(?:[\/\\]+|$)/g;
} else {
var nextPartRe = /(.*?)(?:[\/]+|$)/g;
}
// Regex to find the device root, including trailing slash. E.g. 'c:\\'.
if (isWindows) {
var splitRootRe = /^(?:[a-zA-Z]:|[\\\/]{2}[^\\\/]+[\\\/][^\\\/]+)?[\\\/]*/;
} else {
var splitRootRe = /^[\/]*/;
}
exports.realpathSync = function realpathSync(p, cache) {
// make p is absolute
p = pathModule.resolve(p);
if (cache && Object.prototype.hasOwnProperty.call(cache, p)) {
return cache[p];
}
var original = p,
seenLinks = {},
knownHard = {};
// current character position in p
var pos;
// the partial path so far, including a trailing slash if any
var current;
// the partial path without a trailing slash (except when pointing at a root)
var base;
// the partial path scanned in the previous round, with slash
var previous;
start();
function start() {
// Skip over roots
var m = splitRootRe.exec(p);
pos = m[0].length;
current = m[0];
base = m[0];
previous = '';
// On windows, check that the root exists. On unix there is no need.
if (isWindows && !knownHard[base]) {
fs.lstatSync(base);
knownHard[base] = true;
}
}
// walk down the path, swapping out linked pathparts for their real
// values
// NB: p.length changes.
while (pos < p.length) {
// find the next part
nextPartRe.lastIndex = pos;
var result = nextPartRe.exec(p);
previous = current;
current += result[0];
base = previous + result[1];
pos = nextPartRe.lastIndex;
// continue if not a symlink
if (knownHard[base] || (cache && cache[base] === base)) {
continue;
}
var resolvedLink;
if (cache && Object.prototype.hasOwnProperty.call(cache, base)) {
// some known symbolic link. no need to stat again.
resolvedLink = cache[base];
} else {
var stat = fs.lstatSync(base);
if (!stat.isSymbolicLink()) {
knownHard[base] = true;
if (cache) cache[base] = base;
continue;
}
// read the link if it wasn't read before
// dev/ino always return 0 on windows, so skip the check.
var linkTarget = null;
if (!isWindows) {
var id = stat.dev.toString(32) + ':' + stat.ino.toString(32);
if (seenLinks.hasOwnProperty(id)) {
linkTarget = seenLinks[id];
}
}
if (linkTarget === null) {
fs.statSync(base);
linkTarget = fs.readlinkSync(base);
}
resolvedLink = pathModule.resolve(previous, linkTarget);
// track this, if given a cache.
if (cache) cache[base] = resolvedLink;
if (!isWindows) seenLinks[id] = linkTarget;
}
// resolve the link, then start over
p = pathModule.resolve(resolvedLink, p.slice(pos));
start();
}
if (cache) cache[original] = p;
return p;
};
exports.realpath = function realpath(p, cache, cb) {
if (typeof cb !== 'function') {
cb = maybeCallback(cache);
cache = null;
}
// make p is absolute
p = pathModule.resolve(p);
if (cache && Object.prototype.hasOwnProperty.call(cache, p)) {
return process.nextTick(cb.bind(null, null, cache[p]));
}
var original = p,
seenLinks = {},
knownHard = {};
// current character position in p
var pos;
// the partial path so far, including a trailing slash if any
var current;
// the partial path without a trailing slash (except when pointing at a root)
var base;
// the partial path scanned in the previous round, with slash
var previous;
start();
function start() {
// Skip over roots
var m = splitRootRe.exec(p);
pos = m[0].length;
current = m[0];
base = m[0];
previous = '';
// On windows, check that the root exists. On unix there is no need.
if (isWindows && !knownHard[base]) {
fs.lstat(base, function(err) {
if (err) return cb(err);
knownHard[base] = true;
LOOP();
});
} else {
process.nextTick(LOOP);
}
}
// walk down the path, swapping out linked pathparts for their real
// values
function LOOP() {
// stop if scanned past end of path
if (pos >= p.length) {
if (cache) cache[original] = p;
return cb(null, p);
}
// find the next part
nextPartRe.lastIndex = pos;
var result = nextPartRe.exec(p);
previous = current;
current += result[0];
base = previous + result[1];
pos = nextPartRe.lastIndex;
// continue if not a symlink
if (knownHard[base] || (cache && cache[base] === base)) {
return process.nextTick(LOOP);
}
if (cache && Object.prototype.hasOwnProperty.call(cache, base)) {
// known symbolic link. no need to stat again.
return gotResolvedLink(cache[base]);
}
return fs.lstat(base, gotStat);
}
function gotStat(err, stat) {
if (err) return cb(err);
// if not a symlink, skip to the next path part
if (!stat.isSymbolicLink()) {
knownHard[base] = true;
if (cache) cache[base] = base;
return process.nextTick(LOOP);
}
// stat & read the link if not read before
// call gotTarget as soon as the link target is known
// dev/ino always return 0 on windows, so skip the check.
if (!isWindows) {
var id = stat.dev.toString(32) + ':' + stat.ino.toString(32);
if (seenLinks.hasOwnProperty(id)) {
return gotTarget(null, seenLinks[id], base);
}
}
fs.stat(base, function(err) {
if (err) return cb(err);
fs.readlink(base, function(err, target) {
if (!isWindows) seenLinks[id] = target;
gotTarget(err, target);
});
});
}
function gotTarget(err, target, base) {
if (err) return cb(err);
var resolvedLink = pathModule.resolve(previous, target);
if (cache) cache[base] = resolvedLink;
gotResolvedLink(resolvedLink);
}
function gotResolvedLink(resolvedLink) {
// resolve the link, then start over
p = pathModule.resolve(resolvedLink, p.slice(pos));
start();
}
};