fs: Support mode/flag options to read/append/writeFile

Fix #4841

1 files changed, 85 insertions, 43 deletions

diff --git a/lib/fs.js b/lib/fs.js
index a1bc487b3..1ad0b2e3c 100644
--- a/lib/fs.js
+++ b/lib/fs.js
@@ -165,10 +165,20 @@ fs.existsSync = function(path) {
   }
 };
 
-fs.readFile = function(path, encoding_) {
-  var encoding = typeof(encoding_) === 'string' ? encoding_ : null;
+fs.readFile = function(path, options, callback_) {
   var callback = maybeCallback(arguments[arguments.length - 1]);
 
+  if (typeof options === 'function' || !options) {
+    options = { encoding: null, flag: 'r' };
+  } else if (typeof options === 'string') {
+    options = { encoding: options, flag: 'r' };
+  } else if (!options) {
+    options = { encoding: null, flag: 'r' };
+  } else if (typeof options !== 'object') {
+    throw new TypeError('Bad arguments');
+  }
+
+  var encoding = options.encoding;
   assertEncoding(encoding);
 
   // first, stat the file, so we know the size.
@@ -178,7 +188,8 @@ fs.readFile = function(path, encoding_) {
   var pos = 0;
   var fd;
 
-  fs.open(path, constants.O_RDONLY, 438 /*=0666*/, function(er, fd_) {
+  var flag = options.flag || 'r';
+  fs.open(path, flag, 438 /*=0666*/, function(er, fd_) {
     if (er) return callback(er);
     fd = fd_;
 
@@ -243,10 +254,20 @@ fs.readFile = function(path, encoding_) {
   }
 };
 
-fs.readFileSync = function(path, encoding) {
+fs.readFileSync = function(path, options) {
+  if (!options) {
+    options = { encoding: null, flag: 'r' };
+  } else if (typeof options === 'string') {
+    options = { encoding: options, flag: 'r' };
+  } else if (typeof options !== 'object') {
+    throw new TypeError('Bad arguments');
+  }
+
+  var encoding = options.encoding;
   assertEncoding(encoding);
 
-  var fd = fs.openSync(path, constants.O_RDONLY, 438 /*=0666*/);
+  var flag = options.flag || 'r';
+  var fd = fs.openSync(path, flag, 438 /*=0666*/);
 
   var size;
   var threw = true;
@@ -888,72 +909,93 @@ function writeAll(fd, buffer, offset, length, position, callback) {
   });
 }
 
-fs.writeFile = function(path, data, encoding_, callback) {
-  var encoding = (typeof(encoding_) == 'string' ? encoding_ : 'utf8');
-  assertEncoding(encoding);
+fs.writeFile = function(path, data, options, callback) {
+  var callback = maybeCallback(arguments[arguments.length - 1]);
 
-  callback = maybeCallback(arguments[arguments.length - 1]);
-  fs.open(path, 'w', 438 /*=0666*/, function(openErr, fd) {
+  if (typeof options === 'function' || !options) {
+    options = { encoding: 'utf8', mode: 438 /*=0666*/, flag: 'w' };
+  } else if (typeof options === 'string') {
+    options = { encoding: options, mode: 438, flag: 'w' };
+  } else if (!options) {
+    options = { encoding: 'utf8', mode: 438 /*=0666*/, flag: 'w' };
+  } else if (typeof options !== 'object') {
+    throw new TypeError('Bad arguments');
+  }
+
+  assertEncoding(options.encoding);
+
+  var flag = options.flag || 'w';
+  fs.open(path, options.flag || 'w', options.mode, function(openErr, fd) {
     if (openErr) {
       if (callback) callback(openErr);
     } else {
       var buffer = Buffer.isBuffer(data) ? data : new Buffer('' + data,
-          encoding);
-      writeAll(fd, buffer, 0, buffer.length, 0, callback);
+          options.encoding || 'utf8');
+      var position = /a/.test(flag) ? null : 0;
+      writeAll(fd, buffer, 0, buffer.length, position, callback);
     }
   });
 };
 
-fs.writeFileSync = function(path, data, encoding) {
-  assertEncoding(encoding);
+fs.writeFileSync = function(path, data, options) {
+  if (!options) {
+    options = { encoding: 'utf8', mode: 438 /*=0666*/, flag: 'w' };
+  } else if (typeof options === 'string') {
+    options = { encoding: options, mode: 438, flag: 'w' };
+  } else if (typeof options !== 'object') {
+    throw new TypeError('Bad arguments');
+  }
 
-  var fd = fs.openSync(path, 'w');
+  assertEncoding(options.encoding);
+
+  var flag = options.flag || 'w';
+  var fd = fs.openSync(path, flag);
   if (!Buffer.isBuffer(data)) {
-    data = new Buffer('' + data, encoding || 'utf8');
+    data = new Buffer('' + data, options.encoding || 'utf8');
   }
   var written = 0;
   var length = data.length;
+  var position = /a/.test(flag) ? null : 0;
   try {
     while (written < length) {
-      written += fs.writeSync(fd, data, written, length - written, written);
+      written += fs.writeSync(fd, data, written, length - written, position);
+      position += written;
     }
   } finally {
     fs.closeSync(fd);
   }
 };
 
-fs.appendFile = function(path, data, encoding_, callback) {
-  var encoding = (typeof(encoding_) == 'string' ? encoding_ : 'utf8');
-  assertEncoding(encoding);
+fs.appendFile = function(path, data, options, callback_) {
+  var callback = maybeCallback(arguments[arguments.length - 1]);
 
-  callback = maybeCallback(arguments[arguments.length - 1]);
+  if (typeof options === 'function' || !options) {
+    options = { encoding: 'utf8', mode: 438 /*=0666*/, flag: 'a' };
+  } else if (typeof options === 'string') {
+    options = { encoding: options, mode: 438, flag: 'a' };
+  } else if (!options) {
+    options = { encoding: 'utf8', mode: 438 /*=0666*/, flag: 'a' };
+  } else if (typeof options !== 'object') {
+    throw new TypeError('Bad arguments');
+  }
 
-  fs.open(path, 'a', 438 /*=0666*/, function(err, fd) {
-    if (err) return callback(err);
-    var buffer = Buffer.isBuffer(data) ? data : new Buffer('' + data, encoding);
-    writeAll(fd, buffer, 0, buffer.length, null, callback);
-  });
+  if (!options.flag)
+    options = util._extend({ flag: 'a' }, options);
+  fs.writeFile(path, data, options, callback);
 };
 
-fs.appendFileSync = function(path, data, encoding) {
-  assertEncoding(encoding);
-
-  var fd = fs.openSync(path, 'a');
-  if (!Buffer.isBuffer(data)) {
-    data = new Buffer('' + data, encoding || 'utf8');
+fs.appendFileSync = function(path, data, options) {
+  if (!options) {
+    options = { encoding: 'utf8', mode: 438 /*=0666*/, flag: 'a' };
+  } else if (typeof options === 'string') {
+    options = { encoding: options, mode: 438, flag: 'a' };
+  } else if (typeof options !== 'object') {
+    throw new TypeError('Bad arguments');
   }
-  var written = 0;
-  var position = null;
-  var length = data.length;
+  if (!options.flag)
+    options = util._extend({ flag: 'a' }, options);
 
-  try {
-    while (written < length) {
-      written += fs.writeSync(fd, data, written, length - written, position);
-      position += written; // XXX not safe with multiple concurrent writers?
-    }
-  } finally {
-    fs.closeSync(fd);
-  }
+  fs.writeFileSync(path, data, options);
 };
 
 function errnoException(errorno, syscall) {