RMAN-Executing Operating System Commands from Within RMAN

Problem
You’ve invoked the RMAN client, and now you need to issue some operating system commands.

Solution
Use the RMAN command host to invoke an operating system subshell. You can execute this command in two ways: you can issue it from the RMAN prompt, or you can execute it from inside a run block, which is a group of RMAN commands executed as a single unit. If you issue the host command stand-alone, without any parameters, RMAN will take you to the operating
system command line. Thus, the host command works the same in RMAN as it does from within SQL*Plus. If you issue the command host followed by a valid operating system command as a parameter, then RMAN will execute that operating system command and continue to process the rest of the commands in the run block, if there are any.
In the following example, we use the host command to list all files ending with dbf, after backing up a datafile from the RMAN prompt:

RMAN> shutdown immediate;
RMAN> startup mount;
RMAN> backup datafile '/u01/app/oracle/oradata/targ/system01.dbf' format '/tmp/system01.dbf';
RMAN> host 'ls -l /tmp/*dbf';
RMAN> alter database open;

The following example uses the host command with no parameters to temporarily escape to the operating system level during an interactive RMAN session:

RMAN> backup datafile 3 format '/u01/app/oracle/oradata/targ_db/dbs01.cpy';
RMAN> host;
$ ls $ORACLE_HOME/oradata/dbs01.cpy /net/oracle/oradata/dbs01.cpy
$ exit
RMAN>

How It Works
As you can see in the two examples, you can use the host command with or without an operating system command as a parameter. If you run the host command as part of a series of RMAN commands, RMAN executes the host command and continues with the rest of the commands. When you execute the host command by itself, RMAN displays the operating
system command prompt and resumes after you exit the command-line subshell.