I'm using SQL Developer and I'm trying to save result of a query into the text file using spool command.
SELECT * FROM TABLE
Try to execute it with a query which returns fewer rows to see if you have any other problems. After you make it work, try your query. Also there is a difference between Run Statement and Run Script.
In the following query
spool '/home/atilla/file.txt' SELECT * FROM DUAL; SPOOL OFF
If I use Run Statement, I get following file
> SELECT * FROM DUAL
If I use Run Script, I get following file
\> SELECT * FROM DUAL DUMMY ----- X