Add telnet startup login options

README.md

@@ -25,6 +25,28 @@ If you want to get a hold of the latest version, just go to the Releases page an
 
 Alternatively, most distributions such as Ubuntu, Fedora or Arch already package cool-retro-term in their official repositories.
 
+## Command line
+
+cool-retro-term can run a command on startup with `-e`:
+
+```sh
+cool-retro-term -e top
+```
+
+It can also open a telnet connection on startup:
+
+```sh
+cool-retro-term --telnet-host example.com --telnet-port 23
+```
+
+For telnet servers that prompt for credentials, cool-retro-term can send a username and password when it detects login and password prompts:
+
+```sh
+cool-retro-term --telnet-host example.com --telnet-user myuser --telnet-password mypass
+```
+
+The telnet options use the system `telnet` command, so `telnet` must be installed and available in `PATH`. Passing passwords on the command line can expose them through shell history or process listings.
+
 ## Building
 
 Check out the wiki and follow the instructions on how to build it on [Linux](https://github.com/Swordfish90/cool-retro-term/wiki/Build-Instructions-(Linux)) and [macOS](https://github.com/Swordfish90/cool-retro-term/wiki/Build-Instructions-(macOS)).

app/main.cpp

@@ -3,6 +3,7 @@
 
 #include <QQmlContext>
 #include <QStringList>
+#include <QVariantMap>
 
 #include <QDir>
 
@@ -31,7 +32,7 @@
 QString getNamedArgument(QStringList args, QString name, QString defaultName)
 {
     int index = args.indexOf(name);
-    return (index != -1) ? args[index + 1] : QString(defaultName);
+    return (index != -1 && index + 1 < args.size()) ? args[index + 1] : QString(defaultName);
 }
 
 QString getNamedArgument(QStringList args, QString name)
@@ -64,12 +65,16 @@ int main(int argc, char *argv[])
 
     if (argc>1 && (!strcmp(argv[1],"-h") || !strcmp(argv[1],"--help"))) {
         QTextStream cout(stdout, QIODevice::WriteOnly);
-        cout << "Usage: " << argv[0] << " [--default-settings] [--workdir <dir>] [--program <prog>] [-p|--profile <prof>] [--fullscreen] [-h|--help]" << Qt::endl;
+        cout << "Usage: " << argv[0] << " [--default-settings] [--workdir <dir>] [--program <prog>] [-p|--profile <prof>] [--fullscreen] [--telnet-host <host>] [--telnet-port <port>] [--telnet-user <user>] [--telnet-password <password>] [-h|--help]" << Qt::endl;
         cout << "  --default-settings  Run cool-retro-term with the default settings" << Qt::endl;
         cout << "  --workdir <dir>     Change working directory to 'dir'" << Qt::endl;
         cout << "  -e <cmd>            Command to execute. This option will catch all following arguments, so use it as the last option." << Qt::endl;
         cout << "  --fullscreen        Run cool-retro-term in fullscreen." << Qt::endl;
         cout << "  -p|--profile <prof> Run cool-retro-term with the given profile." << Qt::endl;
+        cout << "  --telnet-host <host>        Connect to a host with telnet on startup." << Qt::endl;
+        cout << "  --telnet-port <port>        Port for --telnet-host. Defaults to telnet's default port." << Qt::endl;
+        cout << "  --telnet-user <user>        Send this username when a login prompt is detected." << Qt::endl;
+        cout << "  --telnet-password <pass>    Send this password when a password prompt is detected." << Qt::endl;
         cout << "  -h|--help           Print this help." << Qt::endl;
         cout << "  --verbose           Print additional information such as profiles and settings." << Qt::endl;
         return 0;
@@ -90,12 +95,19 @@ int main(int argc, char *argv[])
     app.setOrganizationDomain(QStringLiteral("cool-retro-term"));
     app.setApplicationVersion(appVersion);
 
+    QStringList args = app.arguments();
+    const bool hasStartupCommand = args.contains(QStringLiteral("-e")) || args.contains(QStringLiteral("--telnet-host"));
+
     KDSingleApplication singleApp(QStringLiteral("cool-retro-term"));
 
     if (!singleApp.isPrimaryInstance()) {
-        if (singleApp.sendMessage("new-window"))
-            return 0;
-        qWarning() << "KDSingleApplication: primary not reachable, continuing as independent instance.";
+        if (hasStartupCommand) {
+            qInfo() << "KDSingleApplication: startup command requested, continuing as independent instance.";
+        } else {
+            if (singleApp.sendMessage("new-window"))
+                return 0;
+            qWarning() << "KDSingleApplication: primary not reachable, continuing as independent instance.";
+        }
     }
 
     QQmlApplicationEngine engine;
@@ -114,18 +126,33 @@ int main(int argc, char *argv[])
 #endif
 
     // Manage command line arguments from the cpp side
-    QStringList args = app.arguments();
-
     // Manage default command
     QStringList cmdList;
+    const QString telnetHost = getNamedArgument(args, "--telnet-host");
+    const QString telnetPort = getNamedArgument(args, "--telnet-port");
+    const QString telnetUser = getNamedArgument(args, "--telnet-user");
+    const QString telnetPassword = getNamedArgument(args, "--telnet-password");
+
     if (args.contains("-e")) {
         cmdList << args.mid(args.indexOf("-e") + 1);
+    } else if (!telnetHost.isEmpty()) {
+        cmdList << QStringLiteral("telnet") << telnetHost;
+        if (!telnetPort.isEmpty()) {
+            cmdList << telnetPort;
+        }
     }
+
+    QVariantMap telnetLogin;
+    telnetLogin.insert(QStringLiteral("enabled"), !telnetHost.isEmpty() && (!telnetUser.isEmpty() || !telnetPassword.isEmpty()));
+    telnetLogin.insert(QStringLiteral("username"), telnetUser);
+    telnetLogin.insert(QStringLiteral("password"), telnetPassword);
+
     QVariant command(cmdList.empty() ? QVariant() : cmdList[0]);
     QVariant commandArgs(cmdList.size() <= 1 ? QVariant() : QVariant(cmdList.mid(1)));
     engine.rootContext()->setContextProperty("appVersion", appVersion);
     engine.rootContext()->setContextProperty("defaultCmd", command);
     engine.rootContext()->setContextProperty("defaultCmdArgs", commandArgs);
+    engine.rootContext()->setContextProperty("telnetLogin", telnetLogin);
 
     engine.rootContext()->setContextProperty("workdir", getNamedArgument(args, "--workdir", QDir::currentPath()));
     engine.rootContext()->setContextProperty("fileIO", &fileIO);

app/qml/PreprocessedTerminal.qml

@@ -41,6 +41,8 @@ Item{
     property alias title: ksession.title
     property alias kterminal: kterminal
     property bool isActive: false
+    property int telnetLoginState: 0
+    property string telnetPromptBuffer: ""
 
     property size terminalSize: kterminal.terminalSize
     property size fontMetrics: kterminal.fontMetrics
@@ -125,6 +127,10 @@ Item{
             onFinished: {
                 terminalContainer.sessionFinished()
             }
+
+            onReceivedData: function(text) {
+                kterminal.handleTelnetLogin(text)
+            }
         }
 
         QMLTermScrollbar {
@@ -186,6 +192,30 @@ Item{
             ksession.startShellProgram();
             forceActiveFocus();
         }
+
+        function handleTelnetLogin(text) {
+            if (!telnetLogin.enabled || telnetLoginState >= 2) {
+                return;
+            }
+
+            telnetPromptBuffer = (telnetPromptBuffer + text).slice(-512).toLowerCase();
+
+            if (telnetLoginState === 0
+                    && telnetLogin.username
+                    && /(login|username|user)[^a-z0-9]*:\s*$/.test(telnetPromptBuffer)) {
+                ksession.sendText(telnetLogin.username + "\r");
+                telnetLoginState = 1;
+                telnetPromptBuffer = "";
+                return;
+            }
+
+            if (telnetLogin.password
+                    && /password[^a-z0-9]*:\s*$/.test(telnetPromptBuffer)) {
+                ksession.sendText(telnetLogin.password + "\r");
+                telnetLoginState = 2;
+                telnetPromptBuffer = "";
+            }
+        }
         Component.onCompleted: {
             appSettings.fontManager.terminalFontChanged.connect(handleFontChanged);
             appSettings.fontManager.refresh()