When connecting to RMAN, it generates output when any command is given, but the command is not completed and is waiting.
Disruption in executable files.
Close the database and recompile all executable files.
$ cd $ORACLE_HOME/rdbms/lib
$ make -f ins_rdbms.mk install
Make sure that the permissions of the oracle binary file are 6751 (-rwsr-s-x) after this process.
$ cd $ORACLE_HOME/bin
$ chmod 6751 oracle