Allow to get the partition nr from the device node

src/main.cpp

@@ -25,6 +25,45 @@
 #include <KLocalizedString>
 
 #include <config.h>
+#include <utility>
+
+std::pair<QString, QString> parseDevice(const QString& selectedDevice)
+{
+    QString device;
+    QString partitionNr;
+    if (selectedDevice.length()) {
+        const bool isNvme = selectedDevice.startsWith(QStringLiteral("nvme"));
+        // calculate the number of numbers on the last part of the info.
+        int numSize = 0;
+        for (int i = selectedDevice.length() - 1; i > 0; i--) {
+            if (selectedDevice[i].isNumber()) {
+                numSize += 1;
+            } else {
+                if (isNvme) {
+                    // the entry is just an nvme without a partition.
+                    if (selectedDevice[i] != QLatin1Char('p')) {
+                        numSize = 0;
+                        break;
+                    }
+                }
+                break;
+            }
+        }
+        partitionNr = selectedDevice.mid(selectedDevice.length() - numSize);
+
+        if (numSize != 0) {
+            // nvme has a `p` that also needs to be removed.
+            if (isNvme) {
+                numSize += 1;
+            }
+
+            device = selectedDevice.mid(0, selectedDevice.length() - numSize);
+        } else {
+            device = selectedDevice;
+        }
+    }
+    return {device, partitionNr};
+}
 
 int Q_DECL_IMPORT main(int argc, char* argv[])
 {
@@ -75,6 +114,7 @@ int Q_DECL_IMPORT main(int argc, char* argv[])
         return 0;
 
     const QString selectedDevice = parser.value(deviceOption);
+    auto [device, partitionNr] = parseDevice(selectedDevice);
 
     MainWindow* mainWindow = new MainWindow();
     QObject::connect(mainWindow, &MainWindow::scanFinished, mainWindow, [mainWindow, selectedDevice] {