v1.8.14-5 to fix bug causing data lost

### Releases v1.8.14-5

1. Fix bug causing data lost when sending large files. Check [Thread: Teensy 4.1 - Adafruit Airlift Featherwing Co-Processor FTP Server not opening Port 21](https://forum.pjrc.com/threads/70062-Teensy-4-1-Adafruit-Airlift-Featherwing-Co-Processor-FTP-Server-not-opening-Port-21?p=306507&viewfull=1#post306507). This is just a kludge for temporary use, waiting for better and final fix, dealing with SPI driver, from Arduino.
2. Update `Packages' Patches`

CONTRIBUTING.md

@@ -15,7 +15,7 @@ If you don't find anything, please [open a new issue](https://github.com/khoih-p
 Please ensure to specify the following:
 
 * Arduino IDE version (e.g. 1.8.19) or Platform.io version
-* Core Version (e.g. Arduino SAMD core v1.8.13, Adafruit SAMD core v1.7.10, Arduino-mbed RP2040 v3.0.1)
+* Core Version (e.g. Arduino SAMD core v1.8.13, Adafruit SAMD core v1.7.10, Arduino-mbed RP2040 v3.1.1)
 * Board type (e.g. NANO_RP2040_CONNECT, RASPBERRY_PI_PICO, ADAFRUIT_FEATHER_RP2040, GENERIC_RP2040, etc.)
 * Contextual information (e.g. what you were trying to achieve)
 * Simplest possible steps to reproduce
@@ -28,10 +28,10 @@ Please ensure to specify the following:
 
 ```
 Arduino IDE version: 1.8.19
-Arduino-mbed RP2040 v3.0.1
+Arduino-mbed RP2040 v3.1.1
 NANO_RP2040_CONNECT Module
 OS: Ubuntu 20.04 LTS
-Linux xy-Inspiron-3593 5.13.0-40-generic #45~20.04.1-Ubuntu SMP Mon Apr 4 09:38:31 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux
+Linux xy-Inspiron-3593 5.13.0-41-generic #46~20.04.1-Ubuntu SMP Wed Apr 20 13:16:21 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux
 
 Context:
 I encountered an endless loop while trying to connect to Local WiFi.

README.md

@@ -101,7 +101,9 @@
 
 ### Important Notes
 
-Plase use the new firmware `NINA_W102.zip`, modified by [Juraj Andrássy](https://github.com/JAndrassy), from [Using WIFI-NINA with FtpServer; no accept() #31](https://forum.arduino.cc/t/using-wifi-nina-with-ftpserver-no-accept/933690/31) to use with new version [WiFiNINA_Generic v1.8.14-4+](https://github.com/khoih-prog/WiFiNINA_Generic/releases/tag/v1.8.14-4) to fix some issues, such as FTPServer port 23, etc.
+The new [WiFiNINA_Generic v1.8.14-5+](https://github.com/khoih-prog/WiFiNINA_Generic/releases/tag/v1.8.14-5) fixes bug causing data lost when sending large files, such as FTP Client uploading files.
+
+Please use the new firmware `NINA_W102.zip`, modified by [Juraj Andrássy](https://github.com/JAndrassy), from [Using WIFI-NINA with FtpServer; no accept() #31](https://forum.arduino.cc/t/using-wifi-nina-with-ftpserver-no-accept/933690/31) to use with new version [WiFiNINA_Generic v1.8.14-5+](https://github.com/khoih-prog/WiFiNINA_Generic/releases/tag/v1.8.14-4) to fix some issues, such as FTPServer port 23, etc.
 
 ---
 ---
@@ -161,8 +163,8 @@ This [**WiFiNINA_Generic library**](https://github.com/khoih-prog/WiFiNINA_Gener
  7. [`Seeeduino SAMD core 1.8.2+`](https://github.com/Seeed-Studio/ArduinoCore-samd) for SAMD21/SAMD51 boards (XIAO M0, Wio Terminal, etc.). [![Latest release](https://img.shields.io/github/release/Seeed-Studio/ArduinoCore-samd.svg)](https://github.com/Seeed-Studio/ArduinoCore-samd/releases/latest/)
  8. [`Adafruit nRF52 v1.3.0+`](https://www.adafruit.com) for nRF52 boards such as Adafruit NRF52840_FEATHER, NRF52832_FEATHER, NRF52840_FEATHER_SENSE, NRF52840_ITSYBITSY, NRF52840_CIRCUITPLAY, NRF52840_CLUE, NRF52840_METRO, NRF52840_PCA10056, PARTICLE_XENON, **NINA_B302_ublox**, etc. [![GitHub release](https://img.shields.io/github/release/adafruit/Adafruit_nRF52_Arduino.svg)](https://github.com/adafruit/Adafruit_nRF52_Arduino/releases/latest)
  9. [`Arduino Core for STM32 v2.2.0+`](https://github.com/stm32duino/Arduino_Core_STM32) for STM32F/L/H/G/WB/MP1 boards. [![GitHub release](https://img.shields.io/github/release/stm32duino/Arduino_Core_STM32.svg)](https://github.com/stm32duino/Arduino_Core_STM32/releases/latest)
-10. [`Arduino mbed_rp2040 core 3.0.1+`](https://github.com/arduino/ArduinoCore-mbed) for Arduino (Use Arduino Board Manager) RP2040-based boards, such as **Arduino Nano RP2040 Connect, RASPBERRY_PI_PICO, etc.**. [![GitHub release](https://img.shields.io/github/release/arduino/ArduinoCore-mbed.svg)](https://github.com/arduino/ArduinoCore-mbed/releases/latest)
-11. [`Earle Philhower's arduino-pico core v2.0.0+`](https://github.com/earlephilhower/arduino-pico) for RP2040-based boards such as **RASPBERRY_PI_PICO, ADAFRUIT_FEATHER_RP2040 and GENERIC_RP2040**, etc. [![GitHub release](https://img.shields.io/github/release/earlephilhower/arduino-pico.svg)](https://github.com/earlephilhower/arduino-pico/releases/latest)
+10. [`Arduino mbed_rp2040 core 3.1.1+`](https://github.com/arduino/ArduinoCore-mbed) for Arduino (Use Arduino Board Manager) RP2040-based boards, such as **Arduino Nano RP2040 Connect, RASPBERRY_PI_PICO, etc.**. [![GitHub release](https://img.shields.io/github/release/arduino/ArduinoCore-mbed.svg)](https://github.com/arduino/ArduinoCore-mbed/releases/latest)
+11. [`Earle Philhower's arduino-pico core v2.0.2+`](https://github.com/earlephilhower/arduino-pico) for RP2040-based boards such as **RASPBERRY_PI_PICO, ADAFRUIT_FEATHER_RP2040 and GENERIC_RP2040**, etc. [![GitHub release](https://img.shields.io/github/release/earlephilhower/arduino-pico.svg)](https://github.com/earlephilhower/arduino-pico/releases/latest)
 12. [`Arduino AVR core 1.8.5+`](https://github.com/arduino/ArduinoCore-avr) for Arduino AVR boards. Use Arduino Board Manager to install. [![Latest release](https://img.shields.io/github/release/arduino/ArduinoCore-avr.svg)](https://github.com/arduino/ArduinoCore-avr/releases/latest/)
 13. [`Adafruit AVR core 1.4.14+`](https://github.com/adafruit/Adafruit_Arduino_Boards) for Adafruit AVR boards. Use Arduino Board Manager to install. 
 14. [`Sparkfun AVR core 1.1.13+`](https://github.com/sparkfun/Arduino_Boards) for Sparkfun AVR boards. Use Arduino Board Manager to install. 
@@ -412,12 +414,12 @@ With core after v1.5.0, this step is not necessary anymore thanks to the PR [Add
 
 #### 9. For Portenta_H7 boards using Arduino IDE in Linux
 
-  **To be able to upload firmware to Portenta_H7 using Arduino IDE in Linux (Ubuntu, etc.)**, you have to copy the file [portenta_post_install.sh](Packages_Patches/arduino/hardware/mbed_portenta/3.0.0/portenta_post_install.sh) into mbed_portenta directory (~/.arduino15/packages/arduino/hardware/mbed_portenta/3.0.0/portenta_post_install.sh). 
+  **To be able to upload firmware to Portenta_H7 using Arduino IDE in Linux (Ubuntu, etc.)**, you have to copy the file [portenta_post_install.sh](Packages_Patches/arduino/hardware/mbed_portenta/3.1.1/portenta_post_install.sh) into mbed_portenta directory (~/.arduino15/packages/arduino/hardware/mbed_portenta/3.1.1/portenta_post_install.sh). 
 
   Then run the following command using `sudo`
 
 ```
-$ cd ~/.arduino15/packages/arduino/hardware/mbed_portenta/3.0.0
+$ cd ~/.arduino15/packages/arduino/hardware/mbed_portenta/3.1.1
 $ chmod 755 portenta_post_install.sh
 $ sudo ./portenta_post_install.sh
 ```
@@ -430,9 +432,9 @@ This will create the file `/etc/udev/rules.d/49-portenta_h7.rules` as follows:
 SUBSYSTEMS=="usb", ATTRS{idVendor}=="2341", ATTRS{idProduct}=="035b", GROUP="plugdev", MODE="0666"
 ```
 
-Supposing the ArduinoCore-mbed core version is 3.0.0. Now only one file must be copied into the directory:
+Supposing the ArduinoCore-mbed core version is 3.1.1. Now only one file must be copied into the directory:
 
-- `~/.arduino15/packages/arduino/hardware/mbed_portenta/3.0.0/portenta_post_install.sh`
+- `~/.arduino15/packages/arduino/hardware/mbed_portenta/3.1.1/portenta_post_install.sh`
 
 Whenever a new version is installed, remember to copy this files into the new version directory. For example, new version is x.yy.zz
 
@@ -593,7 +595,7 @@ For example
 
 ```
 Start WiFiNINA CheckFirmwareVersion on SAMD_NANO_33_IOT
-WiFiNINA_Generic v1.8.14-4
+WiFiNINA_Generic v1.8.14-5
 Firmware version installed: aaa.bbb.ccc
 Latest firmware version available : aaa.bbb.ccc
 
@@ -687,7 +689,7 @@ The following are screen shot and debug terminal output when running example [Ad
 
 ```
 Starting AdvancedServer on SAMD_NANO_33_IOT
-WiFiNINA_Generic v1.8.14-4
+WiFiNINA_Generic v1.8.14-5
 [NN] ===============================
 [NN] 
 Used/default SPI pinout: 
@@ -840,7 +842,7 @@ The following is debug terminal output when running example [WiFiWebClientRepeat
 
 ```
 Start WiFiWebClientRepeating on MBED NANO_RP2040_CONNECT
-WiFiNINA_Generic v1.8.14-4
+WiFiNINA_Generic v1.8.14-5
 Attempting to connect to SSID: HueNet1
 SSID: HueNet1
 IP Address: 192.168.2.86
@@ -933,7 +935,7 @@ The following is debug terminal output when running example [WiFiWebClientRepeat
 
 ```
 Start WiFiWebClientRepeating on ARDUINO_NANO_RP2040_CONNECT
-WiFiNINA_Generic v1.8.14-4
+WiFiNINA_Generic v1.8.14-5
 Attempting to connect to SSID: HueNet1
 SSID: HueNet1
 IP Address: 192.168.2.86
@@ -1010,7 +1012,7 @@ The following is debug terminal output when running example [WiFiUdpNtpClient](e
 
 ```
 Start WiFiUdpNtpClient on ARDUINO_NANO_RP2040_CONNECT
-WiFiNINA_Generic v1.8.14-4
+WiFiNINA_Generic v1.8.14-5
 Attempting to connect to SSID: HueNet1
 Connected to WiFi
 SSID: HueNet1
@@ -1040,7 +1042,7 @@ The following is debug terminal output when running example [WiFiUdpNtpClient](e
 
 ```
 Start WiFiUdpNtpClient on MBED NANO_RP2040_CONNECT
-WiFiNINA_Generic v1.8.14-4
+WiFiNINA_Generic v1.8.14-5
 Attempting to connect to SSID: HueNet1
 Connected to WiFi
 SSID: HueNet1
@@ -1122,6 +1124,8 @@ Sometimes, the library will only work if you update the `WiFiNINA module/shield`
  - [Watchdog trigger changes #208](https://github.com/arduino-libraries/WiFiNINA/pull/208)
  - [added server.accept() #204](https://github.com/arduino-libraries/WiFiNINA/pull/204)
  - [Fix PinStatus error on some platforms #185](https://github.com/arduino-libraries/WiFiNINA/pull/185)
+23. Fix bug causing data lost when sending large files. This is just a kludge for temporary use, waiting for better and final fix, dealing with SPI driver, from Arduino.
+
 
 ---
 
@@ -1150,6 +1154,8 @@ Submit issues to: [WiFiNINA_Generic issues](https://github.com/khoih-prog/WiFiNI
 9. Thanks to [Mattia Pennasilico](https://github.com/pennam) to create the following PR, used in v1.8.14-4
  - [Watchdog trigger changes #208](https://github.com/arduino-libraries/WiFiNINA/pull/208)
 
+
+
 ---
 
 <table>

changelog.md

@@ -40,6 +40,11 @@
 
 ## Changelog
 
+### Releases v1.8.14-5
+
+1. Fix bug causing data lost when sending large files. Check [Thread: Teensy 4.1 - Adafruit Airlift Featherwing Co-Processor FTP Server not opening Port 21](https://forum.pjrc.com/threads/70062-Teensy-4-1-Adafruit-Airlift-Featherwing-Co-Processor-FTP-Server-not-opening-Port-21?p=306507&viewfull=1#post306507). This is just a kludge for temporary use, waiting for better and final fix, dealing with SPI driver, from Arduino.
+2. Update `Packages' Patches`
+
 ### Releases v1.8.14-4
 
 1. Fix bugs by using some unmerged PRs from original WiFiNINA, such as:

library.json

@@ -1,6 +1,6 @@
 {
   "name": "WiFiNINA_Generic",
-  "version": "1.8.14-4",
+  "version": "1.8.14-5",
   "keywords": "wifi, wi-fi, WiFiNINA, NINA-B302-ublox, W101, W102, shield, Teensy, SAM DUE, SAMD, STM32, nRF52, rpi-pico, rp2040, Credentials, Manager, nano-rp2040-connect, raspberry-pi-pico, mega, 32u4",
   "description": "Enables network connection (local and Internet) and WiFiStorage for SAM DUE, SAMD21, SAMD51, Teensy, AVR (328P, 32u4, 16u4, etc.), Mega, STM32F/L/H/G/WB/MP1, nRF52, NINA_B302_ublox, NINA_B112_ublox, RP2040-based boards, etc. in addition to Arduino MKR WiFi 1010, Arduino MKR VIDOR 4000, Arduino UNO WiFi Rev.2, Nano 33 IoT, Nano RP2040 Connect",
   "authors": [

library.properties

@@ -1,5 +1,5 @@
 name=WiFiNINA_Generic
-version=1.8.14-4
+version=1.8.14-5
 author=Arduino, Khoi Hoang <[email protected]>
 maintainer=Khoi Hoang <[email protected]>
 sentence=Enables network connection (local and Internet) and WiFiStorage for SAM DUE, SAMD21, SAMD51, Teensy, AVR (328P, 32u4, 16u4, etc.), Mega, STM32F/L/H/G/WB/MP1, nRF52, NINA_B302_ublox, NINA_B112_ublox, RP2040-based boards, etc. in addition to Arduino MKR WiFi 1010, Arduino MKR VIDOR 4000, Arduino UNO WiFi Rev.2, Nano 33 IoT, Nano RP2040 Connect

src/WiFiClient_Generic.cpp

@@ -24,7 +24,7 @@
   License along with this library; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
   
-  Version: 1.8.14-4
+  Version: 1.8.14-5
 
   Version Modified By   Date      Comments
   ------- -----------  ---------- -----------
@@ -36,6 +36,7 @@
   1.8.14-2   K Hoang    31/12/2021 Add support to Nano_RP2040_Connect using arduino-pico core
   1.8.14-3   K Hoang    31/12/2021 Fix issue with UDP for Nano_RP2040_Connect using arduino-pico core
   1.8.14-4   K Hoang    01/05/2022 Fix bugs by using some PRs from original WiFiNINA. Add WiFiMulti-related examples
+  1.8.14-5   K Hoang    23/05/2022 Fix bug causing data lost when sending large files
  ***********************************************************************************************************************************/
 
 #define _WIFININA_LOGLEVEL_         1
@@ -274,44 +275,87 @@ size_t WiFiClient::write(uint8_t b)
   return write(&b, 1);
 }
 
+///////////////////////////////////////////////////////////////////////////
+// KH fix bug error when sending repetitively for large file
 size_t WiFiClient::write(const uint8_t *buf, size_t size)
 {
+  NN_LOGDEBUG1("WiFiClient::write: To write, size = ", size);
+
   if (_sock == NO_SOCKET_AVAIL)
   {
     setWriteError();
+
+    NN_LOGDEBUG("WiFiClient::write: NO_SOCKET_AVAIL");
+
     return 0;
   }
 
   if (size == 0)
   {
     setWriteError();
+
+    NN_LOGDEBUG("WiFiClient::write: size = 0");
+
     return 0;
   }
 
   size_t written = ServerDrv::sendData(_sock, buf, size);
 
+  uint8_t timesResent = 0;
+
+  while ( (written != size) && (timesResent++ < 100) )
+  {
+    // Don't use too short delay so that NINA has some time to recover
+    // The fix is considered as kludge, and the correct place to fix is in ServerDrv::sendData()
+    delay(100);
+
+    written += ServerDrv::sendData(_sock, buf + written, size - written);
+  }
+
+  NN_LOGDEBUG1("WiFiClient::write: loopSend => written = ", written);
+  NN_LOGDEBUG1("WiFiClient::write: loopSend => timesResent = ", timesResent);
+
   if (!written && _retrySend) 
   {
     written = retry(buf, size, true);
+
+    NN_LOGDEBUG1("WiFiClient::write: _retrySend => written = ", written);
   }
 
   if (!written)
   {
     // close socket
     ServerDrv::stopClient(_sock);
     setWriteError();
+
+    NN_LOGDEBUG("WiFiClient::write: !written error");
+
     return 0;
   }
 
   if (!ServerDrv::checkDataSent(_sock))
   {
     setWriteError();
+
+    NN_LOGDEBUG("WiFiClient::write: error !checkDataSent");
+
     return 0;
   }
+
+  if (written == size)
+  {
+    NN_LOGINFO1("WiFiClient::write: OK, written = ", written);
+  }
+  else
+  {
+    NN_LOGERROR3("WiFiClient::write: Not OK, size = ", size, ", written = ", written);
+  }
 
   return written;
 }
 
+///////////////////////////////////////////////////////////////////////////
+
 size_t WiFiClient::retry(const uint8_t *buf, size_t size, bool write) 
 {
   size_t rec_bytes = 0;

src/WiFiClient_Generic.h

@@ -24,7 +24,7 @@
   License along with this library; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
   
-  Version: 1.8.14-4
+  Version: 1.8.14-5
 
   Version Modified By   Date      Comments
   ------- -----------  ---------- -----------
@@ -36,6 +36,7 @@
   1.8.14-2   K Hoang    31/12/2021 Add support to Nano_RP2040_Connect using arduino-pico core
   1.8.14-3   K Hoang    31/12/2021 Fix issue with UDP for Nano_RP2040_Connect using arduino-pico core
   1.8.14-4   K Hoang    01/05/2022 Fix bugs by using some PRs from original WiFiNINA. Add WiFiMulti-related examples
+  1.8.14-5   K Hoang    23/05/2022 Fix bug causing data lost when sending large files
  ***********************************************************************************************************************************/
 
 #pragma once

src/WiFiNINA_Generic.h

@@ -24,7 +24,7 @@
   License along with this library; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
   
-  Version: 1.8.14-4
+  Version: 1.8.14-5
 
   Version Modified By   Date      Comments
   ------- -----------  ---------- -----------
@@ -36,6 +36,7 @@
   1.8.14-2   K Hoang    31/12/2021 Add support to Nano_RP2040_Connect using arduino-pico core
   1.8.14-3   K Hoang    31/12/2021 Fix issue with UDP for Nano_RP2040_Connect using arduino-pico core
   1.8.14-4   K Hoang    01/05/2022 Fix bugs by using some PRs from original WiFiNINA. Add WiFiMulti-related examples
+  1.8.14-5   K Hoang    23/05/2022 Fix bug causing data lost when sending large files
  ***********************************************************************************************************************************/
 
 #pragma once

src/WiFiNINA_Pinout_Generic.h

@@ -24,7 +24,7 @@
   License along with this library; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
   
-  Version: 1.8.14-4
+  Version: 1.8.14-5
 
   Version Modified By   Date      Comments
   ------- -----------  ---------- -----------
@@ -36,6 +36,7 @@
   1.8.14-2   K Hoang    31/12/2021 Add support to Nano_RP2040_Connect using arduino-pico core
   1.8.14-3   K Hoang    31/12/2021 Fix issue with UDP for Nano_RP2040_Connect using arduino-pico core
   1.8.14-4   K Hoang    01/05/2022 Fix bugs by using some PRs from original WiFiNINA. Add WiFiMulti-related examples
+  1.8.14-5   K Hoang    23/05/2022 Fix bug causing data lost when sending large files
  ***********************************************************************************************************************************/
 
 #pragma once

src/WiFiSSLClient_Generic.cpp

@@ -24,7 +24,7 @@
   License along with this library; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
   
-  Version: 1.8.14-4
+  Version: 1.8.14-5
 
   Version Modified By   Date      Comments
   ------- -----------  ---------- -----------
@@ -36,6 +36,7 @@
   1.8.14-2   K Hoang    31/12/2021 Add support to Nano_RP2040_Connect using arduino-pico core
   1.8.14-3   K Hoang    31/12/2021 Fix issue with UDP for Nano_RP2040_Connect using arduino-pico core
   1.8.14-4   K Hoang    01/05/2022 Fix bugs by using some PRs from original WiFiNINA. Add WiFiMulti-related examples
+  1.8.14-5   K Hoang    23/05/2022 Fix bug causing data lost when sending large files
  ***********************************************************************************************************************************/
 
 #include "WiFiSSLClient_Generic.h"

src/WiFiSSLClient_Generic.h

@@ -24,7 +24,7 @@
   License along with this library; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
   
-  Version: 1.8.14-4
+  Version: 1.8.14-5
 
   Version Modified By   Date      Comments
   ------- -----------  ---------- -----------
@@ -36,6 +36,7 @@
   1.8.14-2   K Hoang    31/12/2021 Add support to Nano_RP2040_Connect using arduino-pico core
   1.8.14-3   K Hoang    31/12/2021 Fix issue with UDP for Nano_RP2040_Connect using arduino-pico core
   1.8.14-4   K Hoang    01/05/2022 Fix bugs by using some PRs from original WiFiNINA. Add WiFiMulti-related examples
+  1.8.14-5   K Hoang    23/05/2022 Fix bug causing data lost when sending large files
  ***********************************************************************************************************************************/
 
 #pragma once

src/WiFiServer_Generic.cpp

@@ -24,7 +24,7 @@
   License along with this library; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
   
-  Version: 1.8.14-4
+  Version: 1.8.14-5
 
   Version Modified By   Date      Comments
   ------- -----------  ---------- -----------
@@ -36,6 +36,7 @@
   1.8.14-2   K Hoang    31/12/2021 Add support to Nano_RP2040_Connect using arduino-pico core
   1.8.14-3   K Hoang    31/12/2021 Fix issue with UDP for Nano_RP2040_Connect using arduino-pico core
   1.8.14-4   K Hoang    01/05/2022 Fix bugs by using some PRs from original WiFiNINA. Add WiFiMulti-related examples
+  1.8.14-5   K Hoang    23/05/2022 Fix bug causing data lost when sending large files
  ***********************************************************************************************************************************/
 
 #include <string.h>