Oracle database 12C restore script

i'm trying to create backup restore script . in short my backup script creating new directory every day from the operating system level and then backup the database using the directory created i tried the below script but it seems RMAN doesn't recognize the controlfiles here is my script **#RMAN RESTORE SCRIPT** #!/bin/bash #Environment Variables ORACLE_HOME=/u01/app/oracle/product/12.2.0.1/dbhome_1 ORACLE_SID=cdb11 PATH=$PATH:$ORACLE_HOME/bin DD=date +%Y-%m-%d-%H-%M export ORACLE_HOME ORACLE_SID PATH DD controlfile backupsets controlfile=/ArchiveDBBackup/DAILY_RMAN/${DD}/CDB1_CONTROLFILE backupsets=/ArchiveDBBackup/DAILY_RMAN/${DD}/ export controlfile backupsets LOGFILE=/RMAN/log/DAILY_FULLBKP_RESTORE_date +%Y%m%d.log rman target / LOG $LOGFILE RMAN-03002: failure of restore command at 07/04/2021 09:35:57 RMAN-06172: no AUTOBACKUP found or specified handle is not a valid copy or piece any idea how can RMAN recognize linux variables ? or anyway to achieve the restore with those variables ?