Add `-version` option to get just the version

Adds a `-version` or `--version` option to print just the version
of the program for bitcoind, bitcoin-cli and bitcoin-qt.

Also make it that `-help` can be used to display the help (as well as
existing `--help`). Up to now, `-help` was the only option that didn't
work with either one or two dashes.

4 files changed, 14 insertions, 16 deletions

diff --git a/src/qt/bitcoin.cpp b/src/qt/bitcoin.cpp
index 2be8191eb5..387f6ede4b 100644
--- a/src/qt/bitcoin.cpp
+++ b/src/qt/bitcoin.cpp
@@ -503,9 +503,9 @@ int main(int argc, char *argv[])
 
     // Show help message immediately after parsing command-line options (for "-lang") and setting locale,
     // but before showing splash screen.
-    if (mapArgs.count("-?") || mapArgs.count("--help"))
+    if (mapArgs.count("-?") || mapArgs.count("-help") || mapArgs.count("-version"))
     {
-        HelpMessageDialog help(NULL);
+        HelpMessageDialog help(NULL, mapArgs.count("-version"));
         help.showOrPrint();
         return 1;
     }
diff --git a/src/qt/bitcoingui.cpp b/src/qt/bitcoingui.cpp
index 3469f990ac..847a3ab8f1 100644
--- a/src/qt/bitcoingui.cpp
+++ b/src/qt/bitcoingui.cpp
@@ -556,7 +556,7 @@ void BitcoinGUI::aboutClicked()
 
 void BitcoinGUI::showHelpMessageClicked()
 {
-    HelpMessageDialog *help = new HelpMessageDialog(this);
+    HelpMessageDialog *help = new HelpMessageDialog(this, false);
     help->setAttribute(Qt::WA_DeleteOnClose);
     help->show();
 }
diff --git a/src/qt/utilitydialog.cpp b/src/qt/utilitydialog.cpp
index 01b710e876..435c6a4368 100644
--- a/src/qt/utilitydialog.cpp
+++ b/src/qt/utilitydialog.cpp
@@ -57,21 +57,20 @@ void AboutDialog::on_buttonBox_accepted()
 }
 
 /** "Help message" dialog box */
-HelpMessageDialog::HelpMessageDialog(QWidget *parent) :
+HelpMessageDialog::HelpMessageDialog(QWidget *parent, bool versionOnly) :
     QDialog(parent),
     ui(new Ui::HelpMessageDialog)
 {
     ui->setupUi(this);
     GUIUtil::restoreWindowGeometry("nHelpMessageDialogWindow", this->size(), this);
 
-    header = tr("Bitcoin Core") + " " + tr("version") + " " +
-        QString::fromStdString(FormatFullVersion()) + "\n\n" +
-        tr("Usage:") + "\n" +
+    QString version = tr("Bitcoin Core") + " " + tr("version") + " " + QString::fromStdString(FormatFullVersion());
+    QString header = tr("Usage:") + "\n" +
         "  bitcoin-qt [" + tr("command-line options") + "]                     " + "\n";
 
-    coreOptions = QString::fromStdString(HelpMessage(HMM_BITCOIN_QT));
+    QString coreOptions = QString::fromStdString(HelpMessage(HMM_BITCOIN_QT));
 
-    uiOptions = tr("UI options") + ":\n" +
+    QString uiOptions = tr("UI options") + ":\n" +
         "  -choosedatadir            " + tr("Choose data directory on startup (default: 0)") + "\n" +
         "  -lang=<lang>              " + tr("Set language, for example \"de_DE\" (default: system locale)") + "\n" +
         "  -min                      " + tr("Start minimized") + "\n" +
@@ -81,7 +80,10 @@ HelpMessageDialog::HelpMessageDialog(QWidget *parent) :
     ui->helpMessageLabel->setFont(GUIUtil::bitcoinAddressFont());
 
     // Set help message text
-    ui->helpMessageLabel->setText(header + "\n" + coreOptions + "\n" + uiOptions);
+    if(versionOnly)
+        ui->helpMessageLabel->setText(version);
+    else
+        ui->helpMessageLabel->setText(version + "\n" + header + "\n" + coreOptions + "\n" + uiOptions);
 }
 
 HelpMessageDialog::~HelpMessageDialog()
@@ -93,8 +95,7 @@ HelpMessageDialog::~HelpMessageDialog()
 void HelpMessageDialog::printToConsole()
 {
     // On other operating systems, the expected action is to print the message to the console.
-    QString strUsage = header + "\n" + coreOptions + "\n" + uiOptions + "\n";
-    fprintf(stdout, "%s", strUsage.toStdString().c_str());
+    fprintf(stdout, "%s\n", qPrintable(ui->helpMessageLabel->text()));
 }
 
 void HelpMessageDialog::showOrPrint()
diff --git a/src/qt/utilitydialog.h b/src/qt/utilitydialog.h
index 874daf6a7f..cc23420169 100644
--- a/src/qt/utilitydialog.h
+++ b/src/qt/utilitydialog.h
@@ -40,7 +40,7 @@ class HelpMessageDialog : public QDialog
     Q_OBJECT
 
 public:
-    explicit HelpMessageDialog(QWidget *parent);
+    explicit HelpMessageDialog(QWidget *parent, bool versionOnly);
     ~HelpMessageDialog();
 
     void printToConsole();
@@ -48,9 +48,6 @@ public:
 
 private:
     Ui::HelpMessageDialog *ui;
-    QString header;
-    QString coreOptions;
-    QString uiOptions;
 
 private slots:
     void on_okButton_accepted();