Re: [Help-bash] prompt help

[Chet Ramey]

On 2/13/12 8:31 AM, Greg Wooledge wrote:
> On Mon, Feb 13, 2012 at 01:37:39PM +0300, Mihamina Rakotomandimby wrote:
>> Hi all,
>>
>> Running Bash 4.2.20, I would like to have a prompt composed by the first 
>> letters of the base path, excluding the last one.
>>
>>
>> Example:
>> - /u/l/bin if I'm in /usr/local/bin
>> - /v/w/h/my-website if I'm in /var/www/html/my-website
>> - /h/mihamina if I'm in /home/mihamina
> 
> There are a couple approaches that will work for this.  Both of them
> involve setting variables in your dot-files (~/.bashrc or ~/.bash_profile
> or ~/.profile).  There are two variables that govern what bash does
> with the prompt: PROMPT_COMMAND and PS1.  They are very different, but
> they can be made to work together.

I favor writing the code that Greg described, but calling it from function
replacements for `cd' (and, optionally, `pushd' and `popd').  That way you
avoid the overhead of reevaluating PS1 before every prompt by changing it
only when the current directory changes.  You have to do a little more work
to make sure that the appropriate shell functions are defined in the right
subshells, but that's not hard.

Chet
-- 
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, ITS, CWRU    address@hidden    http://cnswww.cns.cwru.edu/~chet/