The YCQL shell (ycqlsh) is a CLI for interacting with YugabyteDB using YCQL.
From within ycqlsh you can send output to a file instead of to the screen using the CAPTURE command.
Example:
cassandra@ycqlsh> SELECT * FROM my_application.t;
c1 | c2 | c3
----+----+----
1 | A | X
2 | B | Y
3 | C | Z
(3 rows)
cassandra@ycqlsh> CAPTURE '/root/t_data.txt';
Now capturing query output to '/root/t_data.txt'.
cassandra@ycqlsh> SELECT * FROM my_application.t;
cassandra@ycqlsh> CAPTURE OFF;
cassandra@ycqlsh> exit;
[root@localhost ~]# cat /root/t_data.txt
c1 | c2 | c3
----+----+----
1 | A | X
2 | B | Y
3 | C | Z
(3 rows)