Help on zero arguments

ydb/apps/ydb/main.cpp

@@ -13,6 +13,10 @@ int main(int argc, char **argv) {
     try {
         return NYdb::NConsoleClient::NewYCloudClient(argc, argv);
     }
+    catch (const NYdb::NConsoleClient::TMisuseWithHelpException& e) {
+        // command help is already printed. Just exit(1)
+        return EXIT_FAILURE;
+    }
     catch (const NYdb::NConsoleClient::TMisuseException& e) {
         Cerr << e.what() << Endl;
         Cerr << "Try \"--help\" option for more info." << Endl;

ydb/public/lib/ydb_cli/commands/ydb_service_scripting.cpp

@@ -74,8 +74,9 @@ void TCommandExecuteYqlScript::Parse(TConfig& config) {
     ParseInputFormats();
     ParseOutputFormats();
     if (!Script && !ScriptFile) {
-        throw TMisuseException() << "Neither \"Text of script\" (\"--script\", \"-s\") "
-            << "nor \"Path to file with script text\" (\"--file\", \"-f\") were provided.";
+        Cerr << "Neither \"Text of script\" (\"--script\", \"-s\") "
+            << "nor \"Path to file with script text\" (\"--file\", \"-f\") were provided." << Endl;
+        config.PrintHelpAndExit();
     }
     if (Script && ScriptFile) {
         throw TMisuseException() << "Both mutually exclusive options \"Text of script\" (\"--script\", \"-s\") "

ydb/public/lib/ydb_cli/commands/ydb_service_table.cpp

@@ -327,10 +327,11 @@ int TCommandDropTable::Run(TConfig& config) {
     return EXIT_SUCCESS;
 }
 
-void TCommandQueryBase::CheckQueryOptions() const {
+void TCommandQueryBase::CheckQueryOptions(TClientCommand::TConfig& config) const {
     if (!Query && !QueryFile) {
-        throw TMisuseException() << "Neither \"Text of query\" (\"--query\", \"-q\") "
-            << "nor \"Path to file with query text\" (\"--file\", \"-f\") were provided.";
+        Cerr << "Neither \"Text of query\" (\"--query\", \"-q\") "
+            << "nor \"Path to file with query text\" (\"--file\", \"-f\") were provided." << Endl;
+        config.PrintHelpAndExit();
     }
     if (Query && QueryFile) {
         throw TMisuseException() << "Both mutually exclusive options \"Text of query\" (\"--query\", \"-q\") "
@@ -403,7 +404,7 @@ void TCommandExecuteQuery::Parse(TConfig& config) {
             || BatchMode != EBatchMode::Default) && QueryType == "scheme") {
         throw TMisuseException() << "Scheme queries does not support parameter options.";
     }
-    CheckQueryOptions();
+    CheckQueryOptions(config);
     CheckQueryFile();
     ParseParameters(config);
 }
@@ -847,7 +848,7 @@ void TCommandExplain::SaveDiagnosticsToFile(const TString& diagnostics) {
 void TCommandExplain::Parse(TConfig& config) {
     TClientCommand::Parse(config);
     ParseOutputFormats();
-    CheckQueryOptions();
+    CheckQueryOptions(config);
 }
 
 int TCommandExplain::Run(TConfig& config) {

ydb/public/lib/ydb_cli/commands/ydb_service_table.h

@@ -84,7 +84,7 @@ class TCommandDropTable : public TTableCommand, public TCommandWithPath {
 
 class TCommandQueryBase {
 protected:
-    void CheckQueryOptions() const;
+    void CheckQueryOptions(TClientCommand::TConfig& config) const;
     void CheckQueryFile();
 
 protected:

ydb/public/lib/ydb_cli/commands/ydb_sql.cpp

@@ -98,6 +98,11 @@ void TCommandSql::Parse(TConfig& config) {
             Query = ReadFromFile(QueryFile, "query");
         }
     }
+    if (Query.Empty()) {
+        Cerr << "Neither text of script (\"--script\", \"-s\") "
+            << "nor path to file with script text (\"--file\", \"-f\") were provided." << Endl;
+        config.PrintHelpAndExit();
+    }
     // Should be called after setting ReadingSomethingFromStdin
     ParseParameters(config);
 }

ydb/public/lib/ydb_cli/commands/ydb_yql.cpp

@@ -68,6 +68,11 @@ void TCommandYql::Parse(TConfig& config) {
     if (ScriptFile) {
         Script = ReadFromFile(ScriptFile, "script");
     }
+    if (Script.Empty()) {
+        Cerr << "Neither text of script (\"--script\", \"-s\") "
+            << "nor path to file with script text (\"--file\", \"-f\") were provided." << Endl;
+        config.PrintHelpAndExit();
+    }
     if(FlameGraphPath && FlameGraphPath->Empty())
     {
         throw TMisuseException() << "FlameGraph path can not be empty.";

ydb/public/lib/ydb_cli/common/command.h

@@ -204,23 +204,37 @@ class TClientCommand {
             bool minFailed = minSet && count < minValue;
             bool maxFailed = maxSet && count > maxValue;
             if (minFailed || maxFailed) {
+                TStringBuilder errorMessage;
                 if (minSet && maxSet) {
                     if (minValue == maxValue) {
-                        throw TMisuseException() << "Command " << ArgV[0]
+                        errorMessage << "Command " << ArgV[0]
                             << " requires exactly " << minValue << " free arg(s).";
+                    } else {
+                        errorMessage << "Command " << ArgV[0]
+                            << " requires from " << minValue << " to " << maxValue << " free arg(s).";
                     }
-                    throw TMisuseException() << "Command " << ArgV[0]
-                        << " requires from " << minValue << " to " << maxValue << " free arg(s).";
-                }
-                if (minFailed) {
-                    throw TMisuseException() << "Command " << ArgV[0]
+                } else if (minFailed) {
+                    errorMessage << "Command " << ArgV[0]
                         << " requires at least " << minValue << " free arg(s).";
+                } else {
+                    errorMessage << "Command " << ArgV[0]
+                        << " requires at most " << maxValue << " free arg(s).";
+                }
+                if (count == 0) {
+                    Cerr << errorMessage << Endl;
+                    PrintHelpAndExit();
+                } else {
+                    throw TMisuseException() << errorMessage;
                 }
-                throw TMisuseException() << "Command " << ArgV[0]
-                    << " requires at most " << maxValue << " free arg(s).";
             }
         }
 
+        void PrintHelpAndExit() {
+            NLastGetopt::TOptsParser parser(Opts, ArgC, ArgV);
+            parser.PrintUsage(Cerr);
+            throw TMisuseWithHelpException();
+        }
+
     private:
         size_t GetParamsCount() {
             size_t result = 0;

ydb/public/lib/ydb_cli/common/common.h

@@ -23,8 +23,12 @@ namespace NConsoleClient {
     const TString HomeDir = GetHomeDir();
 #endif
 
+// Print 'Try "--help" option for more info'
 class TMisuseException : public yexception {};
 
+// Print command help
+class TMisuseWithHelpException : public TMisuseException {};
+
 class TProfileConfig {
 public:
     TProfileConfig(const TString& profileName);