CLI: Add interactive session mode command open

This change adds a GNU Readline-based interactive mode to keepassxc-cli. If GNU Readline is not available, commands are just read from stdin with no editing or auto-complete support.

DatabaseCommand is modified to add the path to the current database to the arguments passed to executeWithDatabase. In this way, instances of DatabaseCommand do not have to prompt to re-open the database after each invocation, and existing command implementations do not have to be changed to support interactive mode.

This change also introduces a new way of handling commands between interactive and batch modes.

* Fixes #3224.
* Ran make format

src/cli/keepassxc-cli.cpp

@@ -16,14 +16,20 @@
  */
 
 #include <cstdlib>
+#include <memory>
 
 #include <QCommandLineParser>
 #include <QCoreApplication>
+#include <QDir>
+#include <QScopedPointer>
 #include <QStringList>
 
 #include "cli/TextStream.h"
 #include <cli/Command.h>
 
+#include "DatabaseCommand.h"
+#include "Open.h"
+#include "Utils.h"
 #include "config-keepassx.h"
 #include "core/Bootstrap.h"
 #include "core/Tools.h"
@@ -33,6 +39,138 @@
 #include <sanitizer/lsan_interface.h>
 #endif
 
+#if defined(USE_READLINE)
+#include <readline/history.h>
+#include <readline/readline.h>
+#endif
+
+class LineReader
+{
+public:
+    virtual ~LineReader() = default;
+    virtual QString readLine(QString prompt) = 0;
+    virtual bool isFinished() = 0;
+};
+
+class SimpleLineReader : public LineReader
+{
+public:
+    SimpleLineReader()
+        : inStream(stdin, QIODevice::ReadOnly)
+        , outStream(stdout, QIODevice::WriteOnly)
+        , finished(false)
+    {
+    }
+
+    QString readLine(QString prompt) override
+    {
+        outStream << prompt;
+        outStream.flush();
+        QString result = inStream.readLine();
+        if (result.isNull()) {
+            finished = true;
+        }
+        return result;
+    }
+
+    bool isFinished() override
+    {
+        return finished;
+    }
+
+private:
+    TextStream inStream;
+    TextStream outStream;
+    bool finished;
+};
+
+#if defined(USE_READLINE)
+class ReadlineLineReader : public LineReader
+{
+public:
+    ReadlineLineReader()
+        : finished(false)
+    {
+    }
+
+    QString readLine(QString prompt) override
+    {
+        char* result = readline(prompt.toStdString().c_str());
+        if (!result) {
+            finished = true;
+            return {};
+        }
+        add_history(result);
+        QString qstr(result);
+        free(result);
+        return qstr;
+    }
+
+    bool isFinished() override
+    {
+        return finished;
+    }
+
+private:
+    bool finished;
+};
+#endif
+
+void enterInteractiveMode(const QStringList& arguments)
+{
+    // Replace command list with interactive version
+    Commands::setupCommands(true);
+
+    Open o;
+    QStringList openArgs(arguments);
+    openArgs.removeFirst();
+    o.execute(openArgs);
+
+    QScopedPointer<LineReader> reader;
+#if defined(USE_READLINE)
+    reader.reset(new ReadlineLineReader());
+#else
+    reader.reset(new SimpleLineReader());
+#endif
+
+    QSharedPointer<Database> currentDatabase(o.currentDatabase);
+
+    QString command;
+    while (true) {
+        TextStream errorTextStream(Utils::STDERR, QIODevice::WriteOnly);
+
+        QString prompt;
+        if (currentDatabase) {
+            prompt += currentDatabase->metadata()->name();
+            if (prompt.isEmpty()) {
+                prompt += QFileInfo(currentDatabase->filePath()).fileName();
+            }
+        }
+        prompt += "> ";
+        command = reader->readLine(prompt);
+        if (reader->isFinished()) {
+            return;
+        }
+
+        QStringList args = Utils::splitCommandString(command);
+        if (args.empty()) {
+            continue;
+        }
+
+        auto cmd = Commands::getCommand(args[0]);
+        if (!cmd) {
+            errorTextStream << QObject::tr("Unknown command %1").arg(args[0]) << "\n";
+            continue;
+        } else if (cmd->name == "quit" || cmd->name == "exit") {
+            return;
+        }
+
+        cmd->currentDatabase = currentDatabase;
+        cmd->execute(args);
+        currentDatabase = cmd->currentDatabase;
+    }
+}
+
 int main(int argc, char** argv)
 {
     if (!Crypto::init()) {
@@ -44,6 +182,7 @@ int main(int argc, char** argv)
     QCoreApplication::setApplicationVersion(KEEPASSXC_VERSION);
 
     Bootstrap::bootstrap();
+    Commands::setupCommands(false);
 
     TextStream out(stdout);
     QStringList arguments;
@@ -54,7 +193,7 @@ int main(int argc, char** argv)
 
     QString description("KeePassXC command line interface.");
     description = description.append(QObject::tr("\n\nAvailable commands:\n"));
-    for (Command* command : Command::getCommands()) {
+    for (auto& command : Commands::getCommands()) {
         description = description.append(command->getDescriptionLine());
     }
     parser.setApplicationDescription(description);
@@ -84,9 +223,13 @@ int main(int argc, char** argv)
     }
 
     QString commandName = parser.positionalArguments().at(0);
-    Command* command = Command::getCommand(commandName);
+    if (commandName == "open") {
+        enterInteractiveMode(arguments);
+        return EXIT_SUCCESS;
+    }
 
-    if (command == nullptr) {
+    auto command = Commands::getCommand(commandName);
+    if (!command) {
         qCritical("Invalid command %s.", qPrintable(commandName));
         // showHelp exits the application immediately, so we need to set the
         // exit code here.