diff --git a/libs/main/core/picout.cpp b/libs/main/core/picout.cpp
index aa2a30fb..3fcd5e91 100644
--- a/libs/main/core/picout.cpp
+++ b/libs/main/core/picout.cpp
@@ -540,7 +540,7 @@ PICout & PICout::writePIString(const PIString & s) {
 		buffer_->append(s);
 	} else {
 		if (PICout::isOutputDeviceActive(PICout::StdOut)) {
-			for (const PIChar & c: s) std::wcout.put(c.toWChar());
+			for (PIChar c: s) std::wcout.put(c.toWChar());
 		}
 		if (PICout::isOutputDeviceActive(PICout::Buffer)) PICout::__string__().append(s);
 	}
diff --git a/libs/main/core/pistring.cpp b/libs/main/core/pistring.cpp
index 6e13226a..883e5ee2 100644
--- a/libs/main/core/pistring.cpp
+++ b/libs/main/core/pistring.cpp
@@ -28,12 +28,6 @@
 #  include <stringapiset.h>
 #endif
 #include <wchar.h>
-#ifdef ANDROID
-#  if __ANDROID_API__ < 21
-#    define wctomb(s, wc) wcrtomb(s, wc, NULL)
-#    define mbtowc(pwc, s, n) mbrtowc(pwc, s, n, NULL)
-#  endif
-#endif
 
 //! \addtogroup Core
 //! \{
@@ -88,6 +82,8 @@ const float PIString::ElideLeft   = 0.f;
 const float PIString::ElideCenter = .5f;
 const float PIString::ElideRight  = 1.f;
 
+static const char * _PIString_empty_cc = "";
+
 
 #ifndef CC_VC
 #  define pisprintf(f, v) char ch[256]; memset(ch, 0, 256); sprintf(ch, f, v); return PIString(ch);
@@ -235,14 +231,15 @@ void PIString::appendFromChars(const char * c, int s, const char * codepage) {
 	return;
 	//printf("request %d\n", sz);
 #  else
+	mbstate_t state;
+	memset(&state, 0, sizeof(state));
 	wchar_t wc;
-	mbtowc(0,0,0); // reset mbtowc
 	//qDebug() << "FromChars ...";
-	while (s>0) {
+	while (sz = mbrtowc(&wc, c, s, &state) > 0) {
 		//qDebug() << "0" << s;
-		sz = mbtowc(&wc, c, s);
+//		sz = mbrtowc(&wc, c, s, &state);
 		//qDebug() << "1" << sz;
-		if (sz < 1) break;
+//		if (sz < 1) break;
 		push_back(PIChar(wc));
 		c += sz; s -= sz;
 		//qDebug() << "2" << c;
@@ -254,37 +251,30 @@ void PIString::appendFromChars(const char * c, int s, const char * codepage) {
 
 
 PIString PIString::fromConsole(const char * s) {
-	int l = 0;
-	while (s[l] != '\0') ++l;
 	PIString ret;
-	if (l > 0) ret.appendFromChars(s, l, __sysoemname__);
+	if (s[0] != '\0') ret.appendFromChars(s, strlen(s), __sysoemname__);
 	return ret;
 
 }
 
 
 PIString PIString::fromSystem(const char * s) {
-	int l = 0;
-	while (s[l] != '\0') ++l;
 	PIString ret;
-	if (l > 0) ret.appendFromChars(s, l, __syslocname__);
+	if (s[0] != '\0') ret.appendFromChars(s, strlen(s), __syslocname__);
 	return ret;
 }
 
 
 PIString PIString::fromUTF8(const char * s) {
-	int l = 0;
-	while (s[l] != '\0') ++l;
 	PIString ret;
-	if (l > 0) ret.appendFromChars(s, l, __utf8name__);
+	if (s[0] != '\0') ret.appendFromChars(s, strlen(s), __utf8name__);
 	return ret;
 }
 
 
 PIString PIString::fromUTF8(const PIByteArray & ba) {
 	PIString ret;
-	if (ba.isEmpty()) return ret;
-	ret.appendFromChars((const char*)ba.data(), ba.size(), __utf8name__);
+	if (ba.isNotEmpty()) ret.appendFromChars((const char*)ba.data(), ba.size(), __utf8name__);
 	return ret;
 }
 
@@ -296,19 +286,17 @@ PIString PIString::fromAscii(const char * s) {
 
 PIString PIString::fromAscii(const char * s, int len) {
 	PIString ret;
-	ret.reserve(len);
+	ret.resize(len);
 	for (int l = 0; l < len; ++l) {
-		ret.push_back(PIChar(s[l]));
+	  ret[l] = s[l];
 	}
 	return ret;
 }
 
 
 PIString PIString::fromCodepage(const char * s, const char * c) {
-	int l = 0;
-	while (s[l] != '\0') ++l;
 	PIString ret;
-	if (l > 0) ret.appendFromChars(s, l
+	if (s[0] > '\0') ret.appendFromChars(s, strlen(s)
 #ifdef PIP_ICU
 										, c
 #else
@@ -342,7 +330,11 @@ PIString PIString::readableSize(llong bytes) {
 
 
 void PIString::buildData(const char * cp) const {
-	data_.clear();
+	//data_.clear();
+	if (data_) {
+		free(data_);
+		data_ = nullptr;
+	}
 	int sz = 0;
 #ifdef PIP_ICU
 	UErrorCode e((UErrorCode)0);
@@ -371,29 +363,33 @@ void PIString::buildData(const char * cp) const {
 	//printf("WideCharToMultiByte %d %d\n", (uint)(uintptr_t)cp, sz);
 	if (sz <= 0) {
 		//printf("WideCharToMultiByte erro %d\n", GetLastError());
-		data_.push_back(uchar('\0'));
+		data_ = (char *)malloc(1);
+		data_[0] = '\0';
 		return;
 	}
-	data_.resize(sz);
-	WideCharToMultiByte((uint)(uintptr_t)cp, 0, (LPCWCH)PIDeque<PIChar>::data(), PIDeque<PIChar>::size_s(), (LPSTR)data_.data(), data_.size_s(), NULL, NULL);
-	data_.push_back(uchar('\0'));
+	data_ = (char *)malloc(sz+1);
+	//data_.resize(sz);
+	WideCharToMultiByte((uint)(uintptr_t)cp, 0, (LPCWCH)PIDeque<PIChar>::data(), PIDeque<PIChar>::size_s(), (LPSTR)data_, sz, NULL, NULL);
+	data_[sz] = '\0';
 	return;
 #  else
 	wchar_t wc;
-	char tc[8];
-	wctomb(0, 0);
+	//char tc[MB_CUR_MAX];
+	mbstate_t state;
+	memset(&state, 0, sizeof(state));
+	data_ = (char *)malloc(MB_CUR_MAX*size()+1);
+	char *p = data_;
 	for (int i = 0; i < size_s(); ++i) {
-		if (at(i).isAscii()) {
-			data_.push_back(uchar(at(i).toAscii()));
-			continue;
-		}
+//		if (at(i).isAscii()) {
+//			data_.push_back(uchar(at(i).toAscii()));
+//			continue;
+//		}
 		wc = at(i).toWChar();
-		sz = wctomb(tc, wc);
-		for (int b = 0; b < sz; ++b) {
-			data_.push_back(uchar(tc[b]));
-		}
+		sz = wcrtomb(p, wc, &state);
+		if (sz < 0) break;
+		p += sz;
 	}
-	data_.push_back(uchar('\0'));
+	p[0] = '\0';
 #  endif
 #endif
 }
@@ -422,14 +418,14 @@ uint PIString::hash() const {
 
 
 PIByteArray PIString::toUTF8() const {
-	if (isEmpty()) return data_.resized(0);
+	if (isEmpty()) return PIByteArray(1,'\0');
 	buildData(__utf8name__);
-	return data_.resized(data_.size_s() - 1);
+	return PIByteArray(data_, strlen(data_));
 }
 
 
 PIByteArray PIString::toCharset(const char * c) const {
-	if (isEmpty()) return data_.resized(0);
+	if (isEmpty()) return PIByteArray(1,'\0');
 	buildData(
 #ifdef PIP_ICU
 			  c
@@ -439,19 +435,20 @@ PIByteArray PIString::toCharset(const char * c) const {
 #  endif
 #endif
 				);
-	return data_.resized(data_.size_s() - 1);
-
+	return PIByteArray(data_, strlen(data_));
 }
 
 
 PIString & PIString::operator +=(const char * str) {
 	if (!str) return *this;
-	int l = 0;
-	while (str[l] != '\0') ++l;
-	appendFromChars(str, l, __syslocname__);
+	appendFromChars(str, strlen(str), __syslocname__);
 	return *this;
 }
 
+PIString::~PIString() {
+	if(data_) free(data_);
+}
+
 
 PIString & PIString::operator +=(const wchar_t * str) {
 	if (!str) return *this;
@@ -1350,20 +1347,6 @@ PIString PIString::inBrackets(const PIChar start, const PIChar end) const {
 }
 
 
-//! \~\details
-//! \~english It`s equivalent length of char sequence returned by function \a data() - 1, without terminating null-char
-//! \~russian Эквивалентно длине данных, возвращаемых \a data() - 1, без завершающего нулевого байта
-//! \~\code
-//! piCout << PIString("0123456789").lengthAscii(); // 10
-//! piCout << PIString("№1").lengthAscii(); // 3
-//! \endcode
-//! \~\sa \a data()
-int PIString::lengthAscii() const {
-	buildData(__syslocname__);
-	return data_.size_s() - 1;
-}
-
-
 //! \~\details
 //! \~english
 //! This function fill internal buffer by sequence
@@ -1380,8 +1363,9 @@ int PIString::lengthAscii() const {
 //! \endcode
 //! \~\sa \a dataConsole(), \a dataUTF8()
 const char * PIString::data() const {
+	if (isEmpty()) return _PIString_empty_cc;
 	buildData(__syslocname__);
-	return (const char *)(data_.data());
+	return data_;
 }
 
 
@@ -1397,8 +1381,9 @@ const char * PIString::data() const {
 //! действителен до следующего вызова этого метода
 //! \~\sa \a data(), \a dataUTF8()
 const char * PIString::dataConsole() const {
+	if (isEmpty()) return _PIString_empty_cc;
 	buildData(__sysoemname__ );
-	return (const char *)(data_.data());
+	return data_;
 }
 
 
@@ -1414,8 +1399,9 @@ const char * PIString::dataConsole() const {
 //! действителен до следующего вызова этого метода
 //! \~\sa \a data(), \a dataConsole()
 const char * PIString::dataUTF8() const {
+	if (isEmpty()) return _PIString_empty_cc;
 	buildData(__utf8name__);
-	return (const char *)(data_.data());
+	return data_;
 }
 
 
@@ -1431,12 +1417,17 @@ const char * PIString::dataUTF8() const {
 //! действителен до следующего вызова этого метода
 //! \~\sa \a dataConsole(), \a dataUTF8()
 const char * PIString::dataAscii() const {
-	data_.clear();
-	for (int i = 0; i < size_s(); ++i) {
-		data_.push_back(uchar(at(i).ch));
+	if (isEmpty()) return _PIString_empty_cc;
+	if (data_) {
+		free(data_);
+		data_ = nullptr;
 	}
-	data_.push_back(uchar('\0'));
-	return (const char *)data_.data();
+	data_ = (char*)malloc(size()+1);
+	for (int i = 0; i < size_s(); ++i) {
+		data_[i] = uchar(at(i).ch);
+	}
+	data_[size()] = '\0';
+	return data_;
 }
 
 
diff --git a/libs/main/core/pistring.h b/libs/main/core/pistring.h
index 50a61b69..5afa1b01 100644
--- a/libs/main/core/pistring.h
+++ b/libs/main/core/pistring.h
@@ -39,7 +39,7 @@ class PIP_EXPORT PIString: public PIDeque<PIChar>
 public:
 	//! \~english Contructs an empty string
 	//! \~russian Создает пустую строку
-	PIString(): PIDeque<PIChar>() {}
+	PIString(): PIDeque<PIChar>() {data_ = nullptr;}
 
 	//! \~english Value for elide at left
 	//! \~russian Значение для пропуска слева
@@ -62,18 +62,18 @@ public:
 
 	//! \~english Contructs a copy of string
 	//! \~russian Создает копию строки
-	PIString(const PIString & o): PIDeque<PIChar>(o) {}
+	PIString(const PIString & o): PIDeque<PIChar>(o) {data_ = nullptr;}
 
-	PIString(PIString && o): PIDeque<PIChar>(std::move(o)) {}
+	PIString(PIString && o): PIDeque<PIChar>(std::move(o)) {data_ = nullptr;}
 
 	
 	//! \~english Contructs string with single symbol "c"
 	//! \~russian Создает строку из одного символа "c"
-	PIString(const PIChar c): PIDeque<PIChar>() {*this += c;}
+	PIString(const PIChar c): PIDeque<PIChar>() {data_ = nullptr; *this += c;}
 
 	//! \~english Contructs string with single symbol "c"
 	//! \~russian Создает строку из одного символа "c"
-	PIString(const char c): PIDeque<PIChar>() {*this += PIChar(c);}
+	PIString(const char c): PIDeque<PIChar>() {data_ = nullptr; *this += PIChar(c);}
 	
 	//! \~english Contructs string from C-string "str" (system codepage)
 	//! \~russian Создает строку из C-строки "str" (кодировка системы)
@@ -85,7 +85,7 @@ public:
 	//! \~\code
 	//! PIString s("string");
 	//! \endcode
-	PIString(const char * str): PIDeque<PIChar>() {*this += str;}
+	PIString(const char * str): PIDeque<PIChar>() {data_ = nullptr; *this += str;}
 	
 	//! \~english Contructs string from \c wchar_t C-string "str"
 	//! \~russian Создает строку из \c wchar_t C-строки "str"
@@ -97,15 +97,15 @@ public:
 	//! \~\code
 	//! PIString s(L"string");
 	//! \endcode
-	PIString(const wchar_t * str): PIDeque<PIChar>() {*this += str;}
+	PIString(const wchar_t * str): PIDeque<PIChar>() {data_ = nullptr; *this += str;}
 
 	//! \~english Contructs string from byte array "ba" (as UTF-8)
 	//! \~russian Создает строку из байтового массива "ba" (как UTF-8)
-	PIString(const PIByteArray & ba): PIDeque<PIChar>() {*this += ba;}
+	PIString(const PIByteArray & ba): PIDeque<PIChar>() {data_ = nullptr; *this += ba;}
 
 	//! \~english Contructs string from "len" characters of buffer "str"
 	//! \~russian Создает строку из "len" символов массива "str"
-	PIString(const PIChar * str, const int len): PIDeque<PIChar>(str, size_t(len)) {}
+	PIString(const PIChar * str, const int len): PIDeque<PIChar>(str, size_t(len)) {data_ = nullptr;}
 
 	//! \~english Contructs string from "len" characters of buffer "str" (system codepage)
 	//! \~russian Создает строку из "len" символов массива "str" (кодировка системы)
@@ -113,7 +113,7 @@ public:
 	//! \~\code
 	//! PIString s("string", 3); // s = "str"
 	//! \endcode
-	PIString(const char * str, const int len): PIDeque<PIChar>() {appendFromChars(str, len);}
+	PIString(const char * str, const int len): PIDeque<PIChar>() {data_ = nullptr; appendFromChars(str, len);}
 
 	//! \~english Contructs string as sequence of characters "c" of buffer with length "len"
 	//! \~russian Создает строку как последовательность длиной "len" символа "c"
@@ -121,7 +121,7 @@ public:
 	//! \~\code
 	//! PIString s(5, 'p'); // s = "ppppp"
 	//! \endcode
-	PIString(const int len, const char c): PIDeque<PIChar>() {for (int i = 0; i < len; ++i) PIDeque<PIChar>::push_back(PIChar(c));}
+	PIString(const int len, const char c): PIDeque<PIChar>() {data_ = nullptr; for (int i = 0; i < len; ++i) PIDeque<PIChar>::push_back(PIChar(c));}
 
 	//! \~english Contructs string as sequence of symbols "c" of buffer with length "len"
 	//! \~russian Создает строку как последовательность длиной "len" символа "c"
@@ -129,9 +129,9 @@ public:
 	//! \~\code
 	//! PIString s(5, "№"); // s = "№№№№№"
 	//! \endcode
-	PIString(const int len, const PIChar c): PIDeque<PIChar>() {for (int i = 0; i < len; ++i) PIDeque<PIChar>::push_back(c);}
+	PIString(const int len, const PIChar c): PIDeque<PIChar>() {data_ = nullptr; for (int i = 0; i < len; ++i) PIDeque<PIChar>::push_back(c);}
 	
-	~PIString() {}
+	~PIString();
 
 
 	//! \~english Assign operator
@@ -749,10 +749,6 @@ public:
 	//! \~russian Возвращает строку между символами "start" и "end" с начала строки
 	PIString inBrackets(const PIChar start, const PIChar end) const;
 	
-	//! \~english Returns bytes count of this string in system codepage
-	//! \~russian Возвращает объем строки в системной кодировке
-	int lengthAscii() const;
-	
 	//! \~english Returns \c char * representation of this string in system codepage
 	//! \~russian Возвращает \c char * представление строки в системной кодировке
 	const char * data() const;
@@ -773,9 +769,9 @@ public:
 	//! \~russian Возвращает хэш
 	uint hash() const;
 
-	//! \~english Returns \a PIByteArray contains \a data() of this string without terminating null-char
-	//! \~russian Возвращает \a PIByteArray содержащий \a data() строки без завершающего нулевого байта
-	PIByteArray toByteArray() const {buildData(__utf8name__); return data_.resized(data_.size_s() - 1);}
+	//! \~english Same as \a toUTF8().
+	//! \~russian Тоже самое, что \a toUTF8().
+	PIByteArray toByteArray() const {return toUTF8();}
 
 	//! \~english Returns \a PIByteArray contains \a dataUTF8() of this string without terminating null-char
 	//! \~russian Возвращает \a PIByteArray содержащий \a dataUTF8() строки без завершающего нулевого байта
@@ -1402,7 +1398,7 @@ private:
 	void appendFromChars(const char * c, int s, const char * cp = __syslocname__);
 	void buildData(const char * cp = __syslocname__) const;
 	void trimsubstr(int &st, int &fn) const;
-	mutable PIByteArray data_;
+	mutable char * data_;
 };
 
 
diff --git a/libs/main/io_devices/piiostring.cpp b/libs/main/io_devices/piiostring.cpp
index d2587cec..87be818f 100644
--- a/libs/main/io_devices/piiostring.cpp
+++ b/libs/main/io_devices/piiostring.cpp
@@ -67,8 +67,9 @@ int PIIOString::readDevice(void * read_to, int max_size) {
 	PIString rs = str->mid(pos, max_size);
 	pos += max_size;
 	if (pos > str->size_s()) pos = str->size_s();
-	int ret = rs.lengthAscii();
-	memcpy(read_to, rs.data(), rs.lengthAscii());
+	const char * cc = rs.data();
+	int ret = strlen(cc);
+	memcpy(read_to, cc, ret);
 	return ret;
 }
 
@@ -81,7 +82,7 @@ int PIIOString::writeDevice(const void * data, int max_size) {
 	if (rs.size_s() > max_size) rs.resize(max_size);
 	str->insert(pos, rs);
 	pos += rs.size_s();
-	return rs.lengthAscii();
+	return strlen((const char *)data);
 }
 
 
@@ -90,7 +91,7 @@ int PIIOString::writeString(const PIString & string) {
 	if (pos > str->size_s()) pos = str->size_s();
 	str->insert(pos, string);
 	pos += string.size_s();
-	return string.lengthAscii();
+	return string.size_s();
 }
 
 
diff --git a/libs/main/system/piprocess.cpp b/libs/main/system/piprocess.cpp
index a3e3f23b..d4d2e621 100644
--- a/libs/main/system/piprocess.cpp
+++ b/libs/main/system/piprocess.cpp
@@ -115,44 +115,37 @@ void PIProcess::startProc(bool detached) {
 	//cout << "run" << endl;
 	PIString str;
 	/// arguments convertion
-#ifdef WINDOWS
 	int as = 0;
-	piForeachC (PIString & i, args)
-		as += i.lengthAscii() + 3;
+	const char * argscc[args.size()+1];
+	int argsl[args.size()];
+	for (int i = 0; i < args.size_s(); ++i) {
+		argscc[i] = args[i].data();
+		argsl[i] = strlen(argscc[i]);
+		as += argsl[i] + 3;
+	}
+	argscc[args.size()] = 0;
+#ifdef WINDOWS
 	char * a = new char[as];
 	memset(a, ' ', as - 1);
 	as = 0;
 	for (int i = 0; i < args.size_s(); ++i) {
 		str = args[i];
 		a[as] = '"';
-		memcpy(&(a[as + 1]), str.data(), str.lengthAscii());
-		a[as + str.lengthAscii() + 1] = '"';
-		as += str.lengthAscii() + 3;
+		memcpy(&(a[as + 1]), argscc[i], argsl[i]);
+		a[as + argsl[i] + 1] = '"';
+		as += argsl[i] + 3;
 	}
 	a[as - 1] = 0;
 	//piCout << a;
-#else
-	//piCout << "#" << args;
-	char * a[args.size_s() + 1];
-	for (int i = 0; i < args.size_s(); ++i) {
-		str = args[i];
-		//piCout << i << str << str.size() << str.lengthAscii() << str.lengthAscii() << str.lengthAscii();
-		a[i] = new char[str.lengthAscii() + 1];
-		memcpy(a[i], str.data(), str.lengthAscii());
-		a[i][str.lengthAscii()] = 0;
-	}
-	a[args.size_s()] = 0;
 #endif
+#ifndef WINDOWS
 	/// environment convertion
-	char ** e = new char*[env.size_s() + 1];
+	const char * envcc[env.size()+1];
+	envcc[env.size_s()] = 0;
 	for (int i = 0; i < env.size_s(); ++i) {
-		str = env[i];
-		e[i] = new char[str.lengthAscii() + 1];
-		memcpy(e[i], str.data(), str.lengthAscii());
-		e[i][str.lengthAscii()] = 0;
-		//cout << e[i] << endl;
+		envcc[i] = env[i].data();
 	}
-	e[env.size_s()] = 0;
+#endif
 	/// files for stdin/out/err
 	t_in = t_out = t_err = false;
 	if (f_in.path().isEmpty()) {
@@ -196,7 +189,7 @@ void PIProcess::startProc(bool detached) {
 		0,         // Thread handle not inheritable
 		false,     // Set handle inheritance to FALSE
 		detached ? DETACHED_PROCESS/*CREATE_NEW_CONSOLE*/ : 0, // Creation flags
-		0,//e,         // Use environment
+		0,//envcc,         // Use environment
 		wd.isEmpty() ? 0 : wd.data(), // Use working directory
 		&(PRIVATE->si),       // Pointer to STARTUPINFO structure
 		&(PRIVATE->pi)))      // Pointer to PROCESS_INFORMATION structure
@@ -209,7 +202,7 @@ void PIProcess::startProc(bool detached) {
 #else
 
 		//cout << "exec " << tf_in << ", " << tf_out << ", " << tf_err << endl;
-		if (execve(str.data(), a, e) < 0)
+		if (execve(str.data(), argscc, envcc) < 0)
 			piCoutObj << "\"execve" << str << args << "\" error :" << errorString();
 	} else {
 		piMinSleep;
@@ -224,14 +217,8 @@ void PIProcess::startProc(bool detached) {
 #endif
 	if (!detached) execFinished(str, exit_code);
 	is_exec = false;
-	for (int i = 0; i < env.size_s(); ++i)
-		delete e[i];
-	delete[] e;
 #ifdef WINDOWS
-	delete a;
-#else
-	for (int i = 0; i < args.size_s(); ++i)
-		delete a[i];
+	delete[] a;
 #endif
 }