I had a script to shutdown the database. This script runs in the cron Sundays.
The cron somehow did not execute the script.
I thought the script has something wrong, and started commenting out the following lines in the script with a # (pound sign).
# lsnrctl stop
# shutdown immediate << EOF
Then I added a:
select count (*) from dba_data_files;
I tried to run it from the cron but it did not run, so I tried to run it manually, and it started to shutdown the database. The listener was not stopped.
Why the pound sign was respected in a OS command, but the command inside the Sqlplus was executed regardless of the pound sign in fron of the line.
This was done with the oracle user which has this shell in the /etc/passwd: