[SOLVED] Where to set root's prompt ?

jlliagre · 12-01-2012, 04:12 PM

Quote:

Originally Posted by wpeckham

What was the root shell before you hanged it?
I would expect it to be /bin/sh, but you should know.

root's default shell is not /bin/sh on Solaris. It is /sbin/sh and according to his posts, the OP already knows this.

Quote:

If it is the posix shell, or another shell acting in posix mode, you should be able to CREATE a file in the folder that root logon lands you, named .profile. On that folder set PS1 and then export it. I would not get complex here, just two simple lines should do the job.

Code:

PS1='..>'
export PS1

for example.

That is correct and will even work with Solaris non POSIX /sbin/sh. Just a side note, I wouldn't have suggested using this very prompt. The convention is to have something ending with '#' for root and with '$' for other users. '>' is a csh convention and is quite unfortunate, especially for root. I have seen production systems severely damaged after a miscontrolled cut and paste.

shivaa · 12-02-2012, 12:04 AM

Thanks everyone for your kind responses!

FYI, I had creaeted a .bashrc in "/", so when root's shell is set to /bin/bash, then after opening a terminal, it loads the prompt properly from .bashrc and no issues. On the other hand, if I keep root's shell to /sbin/sh, and I invoke bash after openining the terminal, prompt again get set properly.
So there is no issues with .bashrc or /bin/bash. I think no further discussion needed on /bin/bash or .bashrc.

Unsolved questions:
(1) If root's shell is /sbin/sh, then which file comes into effect in order to set root's working environment ?
(2) Which one rules - /etc/profile or ~/.profile ?

I creaeted a .profile in "/", and changed root's shell back to /sbin/sh. This time I simply added following in ~/.profile:

Quote:

PS1='..>'
export PS1

But it's also not working, and system still gives me a "#" when I launch a new terminal. (I even rebooted the system, but nothing worked).
If I invoke "source .profile", then prompt metioned in .profile gets set. But source command (or even setenv, export etc) don't work when I open a new terminal, but I need to invoke "bash" or "tcsh" to get these commands work. So after invoking "bash" or "tcsh", I can use "source .profile" and prompt mentioned in it gets set properly.

FYI, Just after opening the terminal, if I check:

Quote:

echo $PS1
#
env | grep PS1
printenv | grep PS1

These commands returns nothing, except "echo $PS1", which returns a #. So if we consider that it's taking root's prompt from /etc/profile, then I checked and there's nowhere PS1 defined in /etc/profile!

As a conclusion, final question is, from where's it is taking/setting a "#" for root's PS1 variable when open a new terminal??

BTW, I am not a beginner in Solaris, so if anyone has any advanced solution, then you're most welcome!

jlliagre · 12-02-2012, 03:23 AM

Quote:

Originally Posted by shivaa

Unsolved questions:
(1) If root's shell is /sbin/sh, then which file comes into effect in order to set root's working environment ?

/etc/default/login or /etc/default/su (only for the variables documented in that file)
/etc/profile (only for login shells)
/.profile (unless using a graphical environment configured to ignore it)

Quote:

(2) Which one rules - /etc/profile or ~/.profile ?

/etc/profile is read first for login shells but not for non login shells
/.profile (not ~/.profile as this syntax is unknown bin /sbin/sh) is eventually read (unless disabled, see next reply) so anything set here rules /etc/profile.

Quote:

I created a .profile in "/", and changed root's shell back to /sbin/sh. This time I simply added following in ~/.profile:
...
But it's also not working, and system still gives me a "#" when I launch a new terminal. (I even rebooted the system, but nothing worked).

Okay, one way to explain that behavior would be the last line of your /.dtprofile reading

Code:

 DTSOURCEPROFILE=false

Just change it to

Code:

 DTSOURCEPROFILE=true

and /.profile will be read at next login.

Quote:

If I invoke "source .profile", then prompt mentioned in .profile gets set. But source command (or even setenv, export etc) don't work when I open a new terminal, but I need to invoke "bash" or "tcsh" to get these commands work. So after invoking "bash" or "tcsh", I can use "source .profile" and prompt mentioned in it gets set properly.

source and setenv are not standard shell commands, thee first one is a bashism, the second one is a csh command. You should have used the "dot" command, i.e.

Code:

 . .profile

Quote:

As a conclusion, final question is, from where's it is taking/setting a "#" for root's PS1 variable when open a new terminal??

I already answered that one, it defaults to "#" or "$" depending on the user privileges when unset and this is hardcoded in the shell binary.

shivaa · 12-02-2012, 11:23 AM

Hello, I feel we're now close to the solution...

I made following changes in .profile:

Code:

PS1=`who am i | cut -d" " -f1`{`pwd`}\!#   
export PS1

Then rebooted the system, opened a new terminal and it showed prompt:

Code:

root{/}!#

So clearly there was mistake in defining variable PS1 in .profile. But few more challanges left are:

(1) It do not show the command number (i.e. using \!#), but just printing it. Same is working fine in bash.
(2) It do not change the pwd, when I open a new directory, but keep it "/" only.
(3) I want a whitespace just after "#" in this prompt, but couldn't succeed. I left margin of a whitespace after # in .profile, but it didn't work.

I tried to close the PS1 value (i.e. `who am i | cut -d" " -f1`{`pwd`}\!#) within ' ', but then the prompt takes only literal, means prompt is:

Code:

`who am i | cut -d" " -f1`{`pwd`}\!#
`who am i | cut -d" " -f1`{`pwd`}\!#

If I enclose PS1 value within " " in .profile, thenn in prompt it shows values of variables/commands, but again not command number and changed working directory.

druuna · 12-02-2012, 11:58 AM

If a recent version of bash is used, you have some short-cuts you can use:

Code:

PS1=”\u@\h: \W # ”

\u -> user,
\h -> hostname,
\W -> basename of the current working directory

There are a few more, have a look in the bash manual page (look for: PROMPTING).

If this is an older sun box and the above doesn't work, try this:

Code:

PS1='$LOGNAME@`hostname`:$PWD # '

Haven't used sunOS/Solaris in a while, but I'm sure jlliagre will straighten me out if I gave wrong/partially incorrect advise.....

shivaa · 12-02-2012, 12:45 PM

Hello Druuna,
I have already tried all shortcuts like \u, \W, \H etc and even $USER, $PWD... And all are working fine with bash. But not with /sbin/sh.
Root's default shell is /sbin/sh, so when I open a new terminal, it reads /.profile and PS1 defined inside it gets set.

Rest, I have mentioned in my previous post (.. few more challanges left). Those couldn't be solved yet.

jlliagre · 12-02-2012, 03:39 PM

Quote:

Originally Posted by shivaa

Hello Druuna,
I have already tried all shortcuts like \u, \W, \H etc and even $USER, $PWD... And all are working fine with bash. But not with /sbin/sh.

There is no surprise they don't work. They are either bashisms or features introduced long after the original Bourne shell, which /sbin/sh essentially is, was developed. Should you want a dynamic prompt, you need to switch to a different newer shell like ksh or bash.

shivaa · 12-04-2012, 10:41 PM

I finally can conclude:
Prompt can be set in .profile, if shell is /sbin/sh. But older versions of shells have certain limitations, so it should be properly defined.
On the other hand, I have tested all /sbin/sh, /bin/bash, .bashrc and .profile. Now all are working fine after making little changes.

Thanks friends for your time & efforts!