diff --git a/lib/read.ps1 b/lib/read.ps1
index 7f3631a..fdc4c8f 100644
--- a/lib/read.ps1
+++ b/lib/read.ps1
@@ -10,7 +10,7 @@ Param(
   [switch] $noEchoBack,
   [string] $mask,
   [string] $limit,
-  [switch] $cs,
+  [switch] $caseSensitive,
   [switch] $encoded
 )
 
@@ -26,7 +26,7 @@ function decodeDOS ($arg) {
 }
 
 $options = @{}
-foreach ($arg in @('display', 'keyIn', 'noEchoBack', 'mask', 'limit', 'cs', 'encoded')) {
+foreach ($arg in @('display', 'keyIn', 'noEchoBack', 'mask', 'limit', 'caseSensitive', 'encoded')) {
   $options.Add($arg, (Get-Variable $arg -ValueOnly))
 }
 if ($options.encoded) {
@@ -95,8 +95,8 @@ while ($True) {
   # other ctrl-chars
   if ($chunk) { $chunk = $chunk -replace '[\x00-\x08\x0b\x0c\x0e-\x1f\x7f]', '' }
   if ($chunk -and $limitPtn) {
-    if ($options.cs)  { $chunk = $chunk -creplace $limitPtn, '' }
-    else              { $chunk = $chunk -ireplace $limitPtn, '' }
+    if ($options.caseSensitive)   { $chunk = $chunk -creplace $limitPtn, '' }
+    else                          { $chunk = $chunk -ireplace $limitPtn, '' }
   }
 
   if ($chunk) {
diff --git a/lib/read.sh b/lib/read.sh
index 20f6929..6aac68d 100644
--- a/lib/read.sh
+++ b/lib/read.sh
@@ -13,7 +13,7 @@ while [ $# -ge 1 ]; do
     'noechoback')       options_noEchoBack=true;;
     'mask')             shift; options_mask="$1";;
     'limit')            shift; options_limit="$1";;
-    'cs')               options_cs=true;;
+    'caseSensitive')    options_caseSensitive=true;;
     'encoded')          options_encoded=true;;
   esac
   shift
@@ -67,7 +67,7 @@ fi
 [ "$options_keyIn" = true ] && req_size=1
 
 if [ "$options_keyIn" = true ] && [ -n "$options_limit" ]; then
-  if [ "$options_cs" = true ]; then
+  if [ "$options_caseSensitive" = true ]; then
     limit_ptn="$options_limit"
   else
     # Safe list
diff --git a/lib/readline-sync.js b/lib/readline-sync.js
index c5c4a0b..0e6e4bf 100644
--- a/lib/readline-sync.js
+++ b/lib/readline-sync.js
@@ -19,11 +19,17 @@ var
   TTY = process.binding('tty_wrap').TTY,
   childProc = require('child_process'),
 
-  promptText = '> ',
-  encoding = 'utf8',
-  bufSize = 1024,
-  print,
-  mask = '*',
+  defaultOptions = {
+    prompt:         '> ',       // for API
+    noEchoBack:     false,
+    mask:           '*',
+    limit:          '',
+    caseSensitive:  false,
+    noTrim:         false,
+    encoding:       'utf8',
+    bufSize:        1024,
+    print:          null
+  },
   useExt = false,
 
   fdR = 'none', fdW, ttyR, isRawMode = false,
@@ -35,8 +41,9 @@ var
   noEchoBack:     boolean
   mask:           string
   limit:          string (pattern)
-  cs:             boolean
+  caseSensitive:  boolean
   noTrim:         boolean
+  encoding, bufSize, print
 */
 function readlineSync(options) {
   var input = '', displaySave = options.display,
@@ -125,7 +132,8 @@ function readlineSync(options) {
       return true;
     }
 
-    if (useExt || !ttyR || typeof fdW !== 'number' && (options.display || !isCooked)) {
+    if (useExt || !ttyR ||
+        typeof fdW !== 'number' && (options.display || !isCooked)) {
       input = tryExt();
       return;
     }
@@ -139,10 +147,11 @@ function readlineSync(options) {
       input = tryExt();
       return;
     }
-    buffer = new Buffer((reqSize = options.keyIn ? 1 : bufSize));
+    buffer = new Buffer((reqSize = options.keyIn ? 1 : options.bufSize));
 
     if (options.keyIn && options.limit) {
-      limit = new RegExp('[^' + options.limit + ']', 'g' + (options.cs ? '' : 'i'));
+      limit = new RegExp('[^' + options.limit + ']',
+        'g' + (options.caseSensitive ? '' : 'i'));
     }
 
     while (true) {
@@ -156,9 +165,10 @@ function readlineSync(options) {
           return;
         }
       }
-      chunk = readSize > 0 ? buffer.toString(encoding, 0, readSize) : '\n';
+      chunk = readSize > 0 ? buffer.toString(options.encoding, 0, readSize) : '\n';
 
-      if (chunk && typeof(line = (chunk.match(/^(.*?)[\r\n]/) || [])[1]) === 'string') {
+      if (chunk &&
+          typeof(line = (chunk.match(/^(.*?)[\r\n]/) || [])[1]) === 'string') {
         chunk = line;
         atEol = true;
       }
@@ -186,9 +196,10 @@ function readlineSync(options) {
     setRawMode(false);
   })();
 
-  if (typeof print === 'function' && !silent) { // must at least write '\n'
-    print(displaySave + (options.noEchoBack ?
-      (new Array(input.length + 1)).join(options.mask) : input) + '\n', encoding);
+  if (typeof options.print === 'function' && !silent) { // must at least write '\n'
+    options.print(displaySave + (options.noEchoBack ?
+      (new Array(input.length + 1)).join(options.mask) : input) + '\n',
+      options.encoding);
   }
 
   return options.noTrim || options.keyIn ? input : input.trim();
@@ -196,7 +207,7 @@ function readlineSync(options) {
 
 function readlineExt(options) {
   var hostArgs, res = {},
-    execOptions = {env: process.env, encoding: encoding};
+    execOptions = {env: process.env, encoding: options.encoding};
 
   if (!extHostPath) {
     if (IS_WIN) {
@@ -318,17 +329,20 @@ function _execFileSync(options, execOptions) {
     res.error.args = shellArgs;
   }
 
-  while (fs.readFileSync(pathDone, {encoding: encoding}).trim() !== '1') {}
-  if ((exitCode = fs.readFileSync(pathExit, {encoding: encoding}).trim()) === '0') {
+  while (fs.readFileSync(pathDone, {encoding: options.encoding}).trim() !== '1') {}
+  if ((exitCode =
+      fs.readFileSync(pathExit, {encoding: options.encoding}).trim()) === '0') {
     res.input =
-      decipher.update(fs.readFileSync(pathStdout, {encoding: 'binary'}), 'hex', encoding) +
-      decipher.final(encoding);
+      decipher.update(fs.readFileSync(pathStdout, {encoding: 'binary'}),
+        'hex', options.encoding) +
+      decipher.final(options.encoding);
   } else {
     res.error = new Error(DEFAULT_ERR_MSG);
     res.error.method = '_execFileSync';
     res.error.program = shellPath;
     res.error.args = shellArgs;
-    res.error.extMessage = fs.readFileSync(pathStderr, {encoding: encoding}).trim();
+    res.error.extMessage =
+      fs.readFileSync(pathStderr, {encoding: options.encoding}).trim();
     res.error.exitCode = +exitCode;
   }
 
@@ -369,11 +383,17 @@ function getHostArgs(options) {
     noEchoBack:     'boolean',
     mask:           'string',
     limit:          'string',
-    cs:             'boolean',
-    encoded:        'boolean'
+    caseSensitive:  'boolean',
+    encoded:        'boolean'   // added by readlineExt, _execFileSync
   }));
 }
 
+function margeOptions() {
+  var optsHashes = Array.prototype.slice.call(arguments),
+    options = {};
+  return options;
+}
+
 function flattenArray(array, validate) {
   var flatArray = [];
   function parseArray(array) {
@@ -390,47 +410,47 @@ function flattenArray(array, validate) {
 // for dev
 exports._useExtSet = function(use) { useExt = use; };
 
-exports.setPrint = function(fnc) { print = fnc; };
+exports.setPrint = function(fnc) { defaultOptions.print = fnc; };
 
 exports.setPrompt = function(newPrompt) {
 /* jshint eqnull:true */
   if (newPrompt != null) {
 /* jshint eqnull:false */
-    promptText = newPrompt;
+    defaultOptions.prompt = newPrompt;
   }
-  return promptText;
+  return defaultOptions.prompt;
 };
 
 exports.setEncoding = function(newEncoding) {
   if (typeof newEncoding === 'string') {
-    encoding = newEncoding;
+    defaultOptions.encoding = newEncoding;
   }
-  return encoding;
+  return defaultOptions.encoding;
 };
 
 exports.setMask = function(newMask) {
   if (typeof newMask === 'string') {
-    mask = newMask;
+    defaultOptions.mask = newMask;
   }
-  return mask;
+  return defaultOptions.mask;
 };
 
 exports.setBufferSize = function(newBufSize) {
   newBufSize = parseInt(newBufSize, 10);
   if (!isNaN(newBufSize) && typeof newBufSize === 'number') {
-    bufSize = newBufSize;
+    defaultOptions.bufSize = newBufSize;
   }
-  return bufSize;
+  return defaultOptions.bufSize;
 };
 
 exports.prompt = function(options) {
   var readOptions = {
-      display:        promptText + '',
+      display:        defaultOptions.prompt + '',
       keyIn:          false,
       noEchoBack:     !!(options && options.noEchoBack),
-      mask:           mask,
+      mask:           defaultOptions.mask,
       limit:          '',
-      cs:             !!(options && options.caseSensitive),
+      caseSensitive:  !!(options && options.caseSensitive),
       noTrim:         !!(options && options.noTrim)
     };
   return readlineSync(readOptions);
@@ -443,9 +463,9 @@ exports.question = function(query, options) {
 /* jshint eqnull:false */
       keyIn:          false,
       noEchoBack:     !!(options && options.noEchoBack),
-      mask:           mask,
+      mask:           defaultOptions.mask,
       limit:          '',
-      cs:             !!(options && options.caseSensitive),
+      caseSensitive:  !!(options && options.caseSensitive),
       noTrim:         !!(options && options.noTrim)
     };
   return readlineSync(readOptions);
@@ -462,9 +482,9 @@ exports.keyIn = function(query, options) {
 /* jshint eqnull:false */
       keyIn:          true,
       noEchoBack:     !!(options && options.noEchoBack),
-      mask:           mask,
+      mask:           defaultOptions.mask,
       limit:          limit,
-      cs:             !!(options && options.caseSensitive),
+      caseSensitive:  !!(options && options.caseSensitive),
       noTrim:         true
     };
   return readlineSync(readOptions);