关于SED请大家帮我改改SHELL

Transformers

现有一个文件($obsolete_tape)内容如下  我想取其中key那一栏的数字：
RMAN-06009: using target database control file instead of recovery catalog
RMAN-06280: Report of obsolete backups and copies
RMAN-06281: Type                 Key    Completion Time    Filename/Handle
RMAN-06282: -------------------- ------ ------------------ --------------------
RMAN-06284: Backup Set           245    28-NOV-07         
RMAN-06285:   Backup Piece       245    28-NOV-07          RAC1:249_639828715:RMAN FULL DB GDTZHA
RMAN-06284: Backup Set           246    28-NOV-07         
RMAN-06285:   Backup Piece       246    28-NOV-07          cf_250_1
RMAN-06284: Backup Set           247    28-NOV-07         
RMAN-06285:   Backup Piece       247    28-NOV-07          82j26n2b_1_1
RMAN-06284: Backup Set           248    28-NOV-07         
RMAN-06285:   Backup Piece       248    28-NOV-07          83j26nu0_1_1

我现在的脚本如下
del_bpiece="-e /RMAN-06285/ s/\(.* \)\(.*\)$/change backuppiece '\2' delete;/"

echo "allocate channel for delete type 'sbt_tape' ;" > $cmdfile

grep RMAN-06285 $obsolete_tape | sed "$del_bpiece" >> $cmdfile

echo "release channel;" >> $cmdfile


想取出其中key 一栏 但是我取出的结果如下
allocate channel for delete type 'sbt_tape' ;
change backuppiece 'GDTZHA' delete;
change backuppiece 'cf_250_1' delete;
change backuppiece '82j26n2b_1_1' delete;
change backuppiece '83j26nu0_1_1' delete;
release channel;


请大家帮我看看 谢谢

ly5066113

awk 'NR>4{print $4}'

davistar

grep -o '\b[0-9]\{3\}\b' file

Transformers

谢谢楼上的两位 但是我最后是想生成下面的效果，请楼上的2位看下我现在的脚本
change backuppiece '245' delete;
change backuppiece '246' delete;

mcolinc

sed -n 's/RMAN-06285:   Backup Piece       \([0-9]\{3\}\).*/\1/p' urfile

davistar

awk 'NR>4{print "change backuppiece \047"$4"\047 delete;"}' file

Transformers

谢谢楼上几位鼎立相助  已经把脚本修改好并测试通过了
以下是完整脚本，是自动删除RMAN 备份的
# Initialize default connect string variables:
. /home/oracle/.profile
target='target /'

time=`date '+%m%d%H'`
# Initialize filenames:

obsolete_tape=/home/oracle/rmanscript/log/ob_tape_$time.log   # list of obsolete tape backups
cmdfile=/home/oracle/rmanscript/log/delete$time.cmd          # the generated RMAN commmand script
delete_log=/home/oracle/rmanscript/log/deleted_$time.log      # execution log from generated script

# Get a list of obsolete tape files:

rman msgno $target $catalog msglog $obsolete_tape << EOF > /dev/null
report obsolete redundancy=1 until time 'sysdate-15' device type 'sbt_tape';
#report obsolete device type 'sbt_tape';
exit;
EOF

# sed actions:


echo "allocate channel for delete type 'sbt_tape' ;" > $cmdfile

grep RMAN-06285 $obsolete_tape | awk 'NR>4{print "change backupset "$4" delete;"}' - >> $cmdfile

echo "release channel;" >> $cmdfile

#
# Execute the RMAN command file to delete the obsolete files:
#
rman msgno $target msglog $delete_log cmdfile $cmdfile

exit