How to determine which Unix shell you are using

How to determine which Unix shell you are using:

> env | grep SHELL

-or-

> echo $SHELL

-or-

> ps -f ....Will provide a full listing of processes associated
with the current terminal, one of which will be the
shell process.

-or-

> setenv ....On a C shell this will return the current
environment, while other shells will return an error.


Please Note:
The following examples use 'ORACLE_HOME' as the variable name.


BOURNE SHELL(sh):
-----------------

To set environment variables within a Bourne Shell (sh), the variable must be
initialized locally, then exported globally:

> ORACLE_HOME=/u01/app/oracle/product/8.1.7
...defines ORACLE_HOME locally to the shell

> export ORACLE_HOME
...makes it globally available to other processes started from
this shell

To have a variable set automatically when you log into the Bourne Shell of your
Unix server:

Add the above lines (minus the '>' prompt) to the hidden '.profile'
file in your $HOME directory.

If you make changes to your '.profile' and want those changes propagated to
your current running environment (without having to log out, then back in):

> cd $HOME
> . .profile

To unset environment variables within a Bourne Shell (sh):

> unset ORACLE_HOME

To check what an environment variable is set to:

> env | grep ORACLE_HOME


KORN SHELL(ksh):
----------------

To set environment variables within a Korn Shell (ksh), you can use the Bourne
syntax show above, or use the streamlined Korn Shell syntax:

> export ORACLE_HOME=/u01/app/oracle/product/8.1.7

To have a variable set automatically when you log into the Korn Shell of your
Unix server:

Add the above lines (minus the '>' prompt) to the hidden '.profile'
file in your $HOME directory.

If you make changes to your '.profile' and want those changes propagated to
your current running environment (without having to log out, then back in):

> cd $HOME
> . .profile

To unset environment variables within a Korn Shell (ksh), use the same syntax
as you would in a Bourne Shell (sh):

> unset ORACLE_HOME

To check what an environment variable is set to:

> env | grep ORACLE_HOME


C SHELL(csh):
-------------

To set environment variables within a C Shell (csh):

> setenv ORACLE_HOME /u01/app/oracle/product/11.1.0