added line mode, as described in #17

CHANGELOG.md

@@ -1,6 +1,7 @@
 # Changelog
 
 ## Unreleased (but available on Github)
+- Added a line mode toggle as suggested in [#17](https://github.com/LennartHennigs/ESPTelnet/pull/17)
 - Changed `String` arguments to `const String &` and `WiFiClient` argument to `WiFiClient &` to avoid copies as requested in pull request [#16](https://github.com/LennartHennigs/ESPTelnet/pull/16)
 - You can now define a custom port via the `begin(uint16_t port)` function as requested in [#18](https://github.com/LennartHennigs/ESPTelnet/issues/18)
 - Added a `clientDisconnect()` function as requested in [#18](https://github.com/LennartHennigs/ESPTelnet/issues/18)

README.md

@@ -39,6 +39,7 @@ __Output and Input__
 - Via `print()` and `println()` you can output text on the telnet server.
 
 - To receive and parse input from the telnet client you can add a handler via `onInputReceived()`.
+- By default, the library waits for a newline character from the client, and sends data to the callback handler one line at a time. This behaviour can be deactivated by calling `setlineMode(false)`.
 
 __Using it to Debug Code__    
 - A common use case is to use it for debuging remote devices, where you might not have access to Serial. Thus I added a few macros to make debugging easier:

examples/TelnetServerLineMode/TelnetServerLineMode.ino

@@ -0,0 +1,151 @@
+/* ------------------------------------------------- */
+
+#include "ESPTelnet.h"          
+
+/* ------------------------------------------------- */
+
+#define SERIAL_SPEED    9600
+#define WIFI_SSID       "MY SSID"
+#define WIFI_PASSWORD   "MY PASS"
+
+/* ------------------------------------------------- */
+
+
+ESPTelnet telnet;
+IPAddress ip;
+uint16_t  port = 23;
+
+/* ------------------------------------------------- */
+
+void setupSerial(long speed, String msg = "") {
+  Serial.begin(speed);
+  while (!Serial) {
+  }
+  delay(200);  
+  Serial.println();
+  Serial.println();
+  if (msg != "") Serial.println(msg);
+}
+
+/* ------------------------------------------------- */
+
+bool isConnected() {
+  return (WiFi.status() == WL_CONNECTED);
+}
+
+/* ------------------------------------------------- */
+
+bool connectToWiFi(const char* ssid, const char* password, int max_tries = 20, int pause = 500) {
+  int i = 0;
+  WiFi.mode(WIFI_STA);
+  #if defined(ARDUINO_ARCH_ESP8266)
+    WiFi.forceSleepWake();
+    delay(200);
+  #endif
+  WiFi.begin(ssid, password);
+  do {
+    delay(pause);
+    Serial.print(".");
+  } while (!isConnected() || i++ < max_tries);
+  WiFi.setAutoReconnect(true);
+  WiFi.persistent(true);
+  return isConnected();
+}
+
+/* ------------------------------------------------- */
+
+void errorMsg(String error, bool restart = true) {
+  Serial.println(error);
+  if (restart) {
+    Serial.println("Rebooting now...");
+    delay(2000);
+    ESP.restart();
+    delay(2000);
+  }
+}
+
+/* ------------------------------------------------- */
+
+void setupTelnet() {  
+  // passing on functions for various telnet events
+  telnet.onConnect(onTelnetConnect);
+  telnet.onConnectionAttempt(onTelnetConnectionAttempt);
+  telnet.onReconnect(onTelnetReconnect);
+  telnet.onDisconnect(onTelnetDisconnect);
+
+  // passing a lambda function
+  telnet.onInputReceived([](String str) {
+    Serial.print(str);
+  });
+
+  telnet.setLineMode(false);
+  Serial.print("- Telnet Line Mode: "); Serial.println(telnet.isLineModeSet() ? "YES" : "NO");
+
+  Serial.print("- Telnet: ");
+  if (telnet.begin(port)) {
+    Serial.println("running");
+  } else {
+    Serial.println("error.");
+    errorMsg("Will reboot...");
+  }
+}
+
+/* ------------------------------------------------- */
+
+// (optional) callback functions for telnet events
+void onTelnetConnect(String ip) {
+  Serial.print("- Telnet: ");
+  Serial.print(ip);
+  Serial.println(" connected");
+  telnet.println("\nWelcome " + telnet.getIP());
+  telnet.println("(Use ^] + q  to disconnect.)");
+}
+
+void onTelnetDisconnect(String ip) {
+  Serial.print("- Telnet: ");
+  Serial.print(ip);
+  Serial.println(" disconnected");
+}
+
+void onTelnetReconnect(String ip) {
+  Serial.print("- Telnet: ");
+  Serial.print(ip);
+  Serial.println(" reconnected");
+}
+
+void onTelnetConnectionAttempt(String ip) {
+  Serial.print("- Telnet: ");
+  Serial.print(ip);
+  Serial.println(" tried to connected");
+}
+
+/* ------------------------------------------------- */
+
+void setup() {
+  setupSerial(SERIAL_SPEED, "Telnet Test");
+
+  Serial.print("- Wifi: ");
+  connectToWiFi(WIFI_SSID, WIFI_PASSWORD);
+
+  if (isConnected()) {
+    ip = WiFi.localIP();
+    Serial.println();
+    Serial.print("- Telnet: "); Serial.print(ip); Serial.print(" "); Serial.println(port);
+    setupTelnet();
+  } else {
+    Serial.println();    
+    errorMsg("Error connecting to WiFi");
+  }
+}
+
+/* ------------------------------------------------- */
+
+void loop() {
+  telnet.loop();
+
+  // send serial input to telnet as output
+  if (Serial.available()) {
+    telnet.print(Serial.read());
+  }
+}
+//* ------------------------------------------------- */

keywords.txt

@@ -13,4 +13,6 @@ onReconnect	KEYWORD2
 onDisconnect	KEYWORD2
 onInputReceived	KEYWORD2
 emptyClientStream	KEYWORD2
-isClientConnected	KEYWORD2
+isClientConnected	KEYWORD2
+isLineModeSet	KEYWORD2
+setLineMode	KEYWORD2

src/ESPTelnet.cpp

@@ -111,18 +111,31 @@ void ESPTelnet::loop() {
   // gather input
   if (client && isConnected && client.available()) {    
     char c = client.read();
-    if (c != '\n') {
-      if (c >= 32 && c < 127) {
-        input += c; 
+    // collect string
+    if (_lineMode) {
+      if (c != '\n') {
+        if (c >= 32 && c < 127) {
+          input += c; 
+        }
+      // EOL -> send input
+      } else {
+        if (on_input != NULL) on_input(input);
+        input = "";
       }
-    // EOL -> send input
+    // send indvidual characters
     } else {
-      if (on_input != NULL) on_input(input);
-      input = "";
+      if (on_input != NULL) {
+        if (input.length()) {
+          on_input(input + c);
+          input = "";
+        } else {
+          on_input(String(c));
+        }
       }
+    }
   }
-    yield();
-  } 
+  yield();
+} 
 
 /* ------------------------------------------------- */
 
@@ -166,6 +179,18 @@ String ESPTelnet::getIP() const {
 
 /* ------------------------------------------------- */
 
+bool ESPTelnet::isLineModeSet() {
+  return _lineMode;
+}
+
+/* ------------------------------------------------- */
+
+void ESPTelnet::setLineMode(bool value) {
+  _lineMode = value;
+}
+
+/* ------------------------------------------------- */
+
 String ESPTelnet::getLastAttemptIP() const { 
   return attemptIp; 
 }

src/ESPTelnet.h

@@ -34,6 +34,9 @@ class ESPTelnet {
     void println(const char c);
     void println();
 
+    bool isLineModeSet();
+    void setLineMode(bool value);
+
     String getIP() const;
     String getLastAttemptIP() const;
 
@@ -42,7 +45,7 @@ class ESPTelnet {
     void onReconnect(CallbackFunction f);
     void onDisconnect(CallbackFunction f);
     void onInputReceived(CallbackFunction f);
-    
+
     void disconnectClient();
 
   protected:
@@ -53,7 +56,8 @@ class ESPTelnet {
     String attemptIp;
     String input = "";
     uint16_t server_port = 23;
-
+    bool _lineMode = true;
+
     bool isClientConnected(WiFiClient &client);
     void emptyClientStream();