Capture symbolic link into Unix/Linux variables

Question

Say I have a folder with a series of symbolic links:

ussdv103:en195d; default$  pwd
/oradba/app/oracle/admin/database1
ussdv103:en195d; default$  ls -ltr
exp -> /oradba/app/oracle/acfsmounts/global/STREAM2a/database1/exp
dpdump -> /oradba/app/oracle/acfsmounts/global/STREAM2a/database1/dpdump
backup -> /oradba/app/oracle/acfsmounts/global/STREAM2a/database1/backup

Then I issue the following commmands to link it to a different STREAM directory:

unlink $ORACLE_BASE/admin/database1/backup
unlink $ORACLE_BASE/admin/database1/dpdump
unlink $ORACLE_BASE/admin/database1/exp
mkdir -p /oradba/app/oracle/acfsmounts/global/STREAM1a/database1/backup
mkdir -p /oradba/app/oracle/acfsmounts/global/STREAM1a/database1/dpdump
mkdir -p /oradba/app/oracle/acfsmounts/global/STREAM1a/database1/exp
ln -s $ORACLE_BASE/acfsmounts/global/STREAM1a/database1/backup $ORACLE_BASE/admin/database1/backup
ln -s $ORACLE_BASE/acfsmounts/global/STREAM1a/database1/dpdump $ORACLE_BASE/admin/database1/dpdump
ln -s $ORACLE_BASE/acfsmounts/global/STREAM1a/database1/exp    $ORACLE_BASE/admin/database1/exp

Then I would use the following command to copy data from the old STREAM directory to the new STREAM directory:

cp -p -r /oradba/app/oracle/acfsmounts/global/STREAM##/database1/ /oradba/app/oracle/acfsmounts/global/STREAM1a/.

But I have to replace ## so that it reflects the location of the old STREAM directory, so the command will look like this:

cp -p -r /oradba/app/oracle/acfsmounts/global/STREAM2a/database1/ /oradba/app/oracle/acfsmounts/global/STREAM1a/.

How can I capture information about the old STREAM directory before unlinking it so that my copy command automatically replaces ## with the correct location of the old STREAM directory? Is there a Unix/Linux variable I can assign the old symbolic link to and then reference that in the copy command?

Answer 1

Store your old file destinations in a variable using the command readlink to read link information.

OLDBACKUP=`readlink $ORACLE_BASE/admin/database1/backup`
OLDDUMP=`readlink $ORACLE_BASE/admin/database1/backup`
OLDEXP=`readlink $ORACLE_BASE/admin/database1/exp`
NEWBACKUP="/oradba/app/oracle/acfsmounts/global/STREAM1a/database1/backup"
NEWDUMP="/oradba/app/oracle/acfsmounts/global/STREAM1a/database1/dpdump"
NEWEXP="/oradba/app/oracle/acfsmounts/global/STREAM1a/database1/exp"
unlink $ORACLE_BASE/admin/database1/backup
unlink $ORACLE_BASE/admin/database1/dpdump
unlink $ORACLE_BASE/admin/database1/exp
mkdir -p $NEWBACKUP
mkdir -p $NEWDUMP
mkdir -p $NEWEXP
ln -s $NEWBACKUP $ORACLE_BASE/admin/database1/backup
ln -s $NEWDUMP $ORACLE_BASE/admin/database1/dpdump
ln -s $NEWEXP    $ORACLE_BASE/admin/database1/exp

cp -p -r $OLDBACKUP $NEWBACKUP
cp -p -r $OLDDUMP $NEWDUMP
cp -p -r $OLDEXP $NEWEXP