Bash profile

[Shutdown]

Hey guys:

I am having a bash_profile issue.

When I log in as JohnDoe, then issue the command "su root" I am suppose to have root privileges.

I probably do, however it seems I am still in the "bash profile" environment of JohnDoe.

So if I want to issue this command as root: chkconfig --list

It says: command not found

But if I log out completely, then log in as root, I can run that command.

What is the point of issuing "SU" if you're not able to run commands as root user?

[daark.child]

What you describe above is exactly how su is supposed to work. If you want to inherit the environmental variables of the user you are switching to, then you need to use "su -" and not just "su" e.g. to switch to root and inherit the path and other environmental variables, you can do

su -

To switch to user john and inherit their path and other environmental variables

su - john

[Shutdown]

What you describe above is exactly how su is supposed to work. If you want the environmental variables of the user you are switching to, then you need to use "su -" and not just "su".

Ahhh thank you for the quick reply. That did it.

So I guess "su -" will give you ROOT and it's environment, while just "su root" only gives you the privileges to perform root stuff..?

[daark.child]

Ahhh thank you for the quick reply. That did it.

So I guess "su -" will give you ROOT and it's environment, while just "su root" only gives you the privileges to perform root stuff..?

"su" just switches you to a new user (to root if you do not specify a user) but keeps your environmental settings. "su -" switches you to the new user and you also switch to their environmental settings such as their path, aliases etc.

[Shutdown]

Is there any difference between $BASH and $SHELL? I get the same results. Is one deprecated but somehow is still supported for backward compatibility?


[root@linux01 ~]# echo $BASH
/bin/bash

[root@linux01 ~]# echo $SHELL
/bin/bash

[Thrillhouse]

I'm guessing that $BASH is just a short-circuited version of $SHELL (specific to bash obviously). $SHELL is more generic. You happen to be using bash so the two are the same but if you were to be using the korn, shell your $SHELL would be /usr/bin/ksh and you probably would not have a $BASH variable (at least I do not in my korn shell).

[Shutdown]

I'm guessing that $BASH is just a short-circuited version of $SHELL (specific to bash obviously). $SHELL is more generic. You happen to be using bash so the two are the same but if you were to be using the korn, shell your $SHELL would be /usr/bin/ksh and you probably would not have a $BASH variable (at least I do not in my korn shell).

ahh ok. So I confused myself by using bash already, that's why the results look the same.

Is korn a better shell or is it just preference? Also are there a lot of different shell's out there?

Or is Korn and Bash the only two widely used?

[Thrillhouse]

There are a bunch of different shells, of which bash is one. The Bourne again shell (bash) is a follow-on to the Bourne shell (sh). The korn shell is another. There's also the C shell or csh, and the Z shell zsh. The Wikipedia page on UNIX shells is a good place to start:

Unix shell - Wikipedia, the free encyclopedia

There's not too much of a difference between bash and ksh, so if you're a beginner, I would just stick with bash until you find a need to move to another. Most Linux systems default to the bash shell. Although not all UNIX systems do.

[daark.child]

There are many different shells out there. Most Linux distros default to bash, but you can install ksh, pdksh, csh, tcsh, zsh (which is my favourite), fish etc. Search for "linux shells" and "unix shells" and you should be able to find articles that discuss the various shells.

[Shutdown]

Thanks guys, I get the jist of it now on shells.

Once I become more of a power user of linux, I will probably start to find which shell is best for me.