不指定地点对当前控制文件进行备份：
RMAN> backup current controlfile;

Starting backup at 18-MAR-09
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: sid=158 devtype=DISK
channel ORA_DISK_1: starting full datafile backupset
channel ORA_DISK_1: specifying datafile(s) in backupset
including current control file in backupset
channel ORA_DISK_1: starting piece 1 at 18-MAR-09
channel ORA_DISK_1: finished piece 1 at 18-MAR-09
piece handle=/u01/flash_recovery_area/SALIM/backupset/2009_03_18/o1_mf_ncnnf_TAG20090318T062559_4w1m1rm7_.bkp tag=TAG20090318T062559 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:02
Finished backup at 18-MAR-09

Starting Control File and SPFILE Autobackup at 18-MAR-09
piece handle=/tmp/cfc-2484939534-20090318-00 comment=NONE
Finished Control File and SPFILE Autobackup at 18-MAR-09

完成

但是执行

RMAN> backup current controlfile to '/salim/%F.copy';

RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-00558: error encountered while parsing input commands
RMAN-01009: syntax error: found "single-quoted-string": expecting one of: "destination"
RMAN-01007: at line 1 column 31 file: standard input