RMAN> run
2> {
3> sql "alter database mount";
4> }

sql statement: alter database mount

RMAN> RUN
2> {
3> sql "alter database open";
4> }

wt
#   # and --- are comments
#!define environmentvariables in your shell
export ORACLE_SID=AUX_SID		--- sid of aux database to be clone
export ORACLE_BASE=xx
export ORACLE_HOME=xxx
export PATH:$PATH:$ORACLE_HOME/bin
export NLS_DATE_FORMAT='MON DD YYYY HH24:MI:SS'
rman  msglog '/tmp/duplicate.log' <<EOF
connect target sys/sys@target		--- database_or_primarydatabase
connect catalog rmanuser/pass@rmandb  	--- rman catalog database
connect auxiliary  sys/password 	--- this is you auxillary database
					--- if you using connnectstring , change to sys/pass@aux_connecstring.
run {
allocate channel ch1 type disk;
allocate channel ch2 type disk;
ALLOCATE AUXILIARY CHANNEL aux1 DEVICE TYPE DISK;
ALLOCATE AUXILIARY CHANNEL aux2 DEVICE TYPE DISK;
--- OTHER COMMANDS
--- Do your business
duplicate target database to AUX_SID
PFILE = initAUX_SID.ora
--- OTHER COMMANDS
--- Do your business
}
exit
EOF