**Use case**

It prints:
```
ClickHouse has been successfully installed.

Start clickhouse-server with:
 sudo clickhouse start
```

But if clickhouse-server is already running, let's print:
```
ClickHouse has been successfully installed.

Restart clickhouse-server with:
 sudo clickhouse restart
```
{
    if (!group_name.empty())
    {
#if defined(OS_DARWIN)
        
        throw Exception(ErrorCodes::NOT_IMPLEMENTED, "Unable to create a group in macOS");
#else
        std::string command = fmt::format("groupadd -r {}", group_name);
        fmt::print(" {}\n", command);
        executeScript(command);
#endif
    }
}
static void createUser(const String & user_name, [[maybe_unused]] const String & group_name)
{
    if (!user_name.empty())
    {
#if defined(OS_DARWIN)
        
        throw Exception(ErrorCodes::NOT_IMPLEMENTED, "Unable to create a user in macOS");
#else
        std::string command = group_name.empty()
            ? fmt::format("useradd -r --shell /bin/false --home-dir /nonexistent --user-group {}", user_name)
            : fmt::format("useradd -r --shell /bin/false --home-dir /nonexistent -g {} {}", group_name, user_name);
        fmt::print(" {}\n", command);
        executeScript(command);
#endif
    }
}
int mainEntryClickHouseInstall(int argc, char ** argv)