topic Re: OS prompt in Operating System - Linux

OS prompt

Tonatiuh — Thu, 14 Apr 2005 10:23:59 GMT

Default prompt shows:
[username@hostname directory] and an indicator # if root user and $ if another user.

Example:
[oracle@myhostname mydir]$

Using command PS1="..." I can adjust to show more data in the prompt. What variables or parameters or syntax should I use to show the OSUser and the indicator # (for root) or the $ for another users?

Re: OS prompt

Wim Van den Wyngaert — Thu, 14 Apr 2005 10:45:58 GMT

man bash and search for PS1. After a few matches the list is given.

Wim

Re: OS prompt

Wim Van den Wyngaert — Thu, 14 Apr 2005 10:50:20 GMT

And the answer is
PS1="\u\$"

Wim

Re: OS prompt

Paul Cross_1 — Thu, 14 Apr 2005 10:52:43 GMT

This depends on the shell you use.
I'm assuming you use bash, which is the default shell. If so, the prompt commands are all in the man page for that shell under PROMPTING.

For your example, to set the prompt to show the hostname,dash,userid followed by the $ or # do:

PS1="\h-\u\$"

ciao!

Re: OS prompt

Tonatiuh — Thu, 14 Apr 2005 13:23:56 GMT

Wim, Paul,

The $ symbol, just show the same symbol always, but does not change with root or another user, as the default.

Re: OS prompt

Paul Cross_1 — Thu, 14 Apr 2005 13:59:13 GMT

You are right. For the # to show up, your effective UID has to be 0. This means you cannot use su.

In root's .bashrc, you might just want to put in:

PS1="\h-\u#"

-p

Re: OS prompt

Stuart Browne — Thu, 14 Apr 2005 19:45:27 GMT

Are you using '$' or '\$' at the end of your PS1 string?

'\$' is the inbuilt which gets translated to $ or # for a non-priv/priv user.

Re: OS prompt

Stuart Browne — Thu, 14 Apr 2005 20:02:59 GMT

Oh, I forgot.. Beware of shell expansion when setting PS1.

If you:

PS1="\u@\h blah\$"

It won't do what's expected (as the \'s will protect the 'u', the 'h' and a '$' symbol).

So always echo $PS1 back after setting it to make sure it's what you expected.

You may need to escape the \'s (\\$ for instance).

Check your /etc/bashrc for examples.

Re: OS prompt

Paul Cross_1 — Fri, 15 Apr 2005 11:25:17 GMT

argh! my answer was totally wrong! I was sleeping at the wheel. su - gives you an effective uid of 0, i confused real uid vs effective uid. sorry.

Stuart is right, you need to escape the \ like this:

PS1="\h-\u\\$"

-p