**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
```
}
            else if (!sh->out.eof())
            {
                fmt::print("The pidof command returned unusual output.\n");
            }
            WriteBufferFromFileDescriptor std_err(STDERR_FILENO);
            copyData(sh->err, std_err);
            sh->tryWait();
        }
        if (pid)
        {
            if (0 == kill(pid, 0))
            {
                fmt::print("The process with pid = {} is running.\n", pid);
            }
            else if (errno == ESRCH)
            {
                fmt::print("The process with pid = {} does not exist.\n", pid);
                return 0;
            }
            else
                throwFromErrno(fmt::format("Cannot obtain the status of pid {} with `kill`", pid), ErrorCodes::CANNOT_KILL);
        }
        if (!pid)
        {
            fmt::print("Now there is no clickhouse-server process.\n");
        }
        return pid;
    }
    int stop(const fs::path & pid_file, bool force)