linux下oracle instant client安装和运行
Step one:

download the correspondent instantclient from oracle website: http://www.oracle.com/technetwork/topics/linuxsoft-082809.html for my case:

Download instantclient-basic-linux32-10.2.0.3-20061115.zip

step two:
mkdir -p /home/oracle/10.2.3
chown -R oracle:oinstall /home/oracle/10.2.3
chmod -R 775 /home/oracle/10.2.3

su - oracle
cd /home/oracle/10.2.3
unzip instantclient-basic-linux32-10.2.0.3-20061115.zip

step three:

copy sqlnet.ora and tnsname.ora into the directory

step four:
set ORACLE_HOME, ORACLE_SID, TNS_ADMIN, LD_LIBARARY_PATH, PATH

step five:

su - root
vi /etc/ld.so.conf

/home/oracle/10.2.3/instantclient_10_2

step six:
download sqlplus package from website.

issue:

if show missing sp*.msd

then

check if the oracle_home set?

check: type sqlplus to see where the path is.