http://techxploration.blogspot.com/2012/01/resolving-sp2-0750-you-may-need-to-set.html

Resolving SP2-0750: You may need to set ORACLE_HOME to your Oracle software directory

$ sqlplus
SP2-0667: Message file sp1<lang>.msb not found
SP2-0750: You may need to set ORACLE_HOME to your Oracle software directory

/u01/app/oracle/product/11.2.0/xe/

If you have a different set up, adjust your directory path accordingly.

   bash-3.2$ export ORACLE_HOME=/u01/app/oracle/product/11.2.0/xe/

    bash-3.2$ export PATH=/u01/app/oracle/product/11.2.0/xe/bin:$PATH

 
You should now be able to use sqlplus. 

4) Now you need to edit you bash_profile so all these takes effect everytime you log in.

bash-3.2$ cd ~/
bash-3.2$ vim .bash_profile

5) In the .bash_profile you will need to add those export lines so every time you log in the same settings take effect.

bash-3.2$ vim .bash_profile
# .bash_profile

# Get the aliases and functions
if [ -f ~/.bashrc ]; then
        . ~/.bashrc
fi

# User specific environment and startup programs
ORACLE_SID=XE
export ORACLE_SID
ORACLE_HOME=/u01/app/oracle/product/11.2.0/xe
export ORACLE_HOME
PATH=$ORACLE_HOME/bin:$PATH
export PATH
unset USERNAME


6) Run the following:
bash-3.2$ . .bash_profile
 
After following these 6 steps you should be able to connect to sqlplus any time.

[转]sqlplus /nolog 出错解决 SP2-0667: Message file sp1<lang>.msb not found SP2-0750: You may need to set ORACLE_HOME to your Oracle software directory