Tiny problem with a prompt

Tiny problem with a prompt

[Tomasz Moskal]

I am trying to display current directory in different colour based on if
it's writeable or not. What I thought will be simple  if...then...else
task has become a really headache. My (simplistic) code is as follows:


prompt_k2_setup() {
    
    pdir() {
        if [[ -w $PWD ]]; then
            dirp='%3F%1/%3f '
        else
            dirp='%1F%1/%1f '
        fi  
    }   
    
    precmd() { pdir }

    PS1="${dirp} "
}   

prompt_k2_setup "$@"


It sort off works, but not as I intended it to - for the prompt to show
current directory I need to execute  'prompt k2'  each time I change to
different directory.

I am probably missing something painfully obvious but I can't figure it
out. A nudge in the right direction will be greatly appreciated.

Re: Tiny problem with a prompt

[Mikael Magnusson]

On 30 July 2011 14:57, Tomasz Moskal <ramshackle.industries@gmail.com> wrote:
> I am trying to display current directory in different colour based on if
> it's writeable or not. What I thought will be simple  if...then...else
> task has become a really headache. My (simplistic) code is as follows:
>
>
> prompt_k2_setup() {
>
>    pdir() {
>        if [[ -w $PWD ]]; then
>            dirp='%3F%1/%3f '
>        else
>            dirp='%1F%1/%1f '
>        fi
>    }
>
>    precmd() { pdir }
>
>    PS1="${dirp} "
> }
>
> prompt_k2_setup "$@"
>
>
> It sort off works, but not as I intended it to - for the prompt to show
> current directory I need to execute  'prompt k2'  each time I change to
> different directory.
>
> I am probably missing something painfully obvious but I can't figure it
> out. A nudge in the right direction will be greatly appreciated.

You need to update PS1 inside precmd(), or use promptsubst and protect
the parameter expansion.

-- 
Mikael Magnusson

Re: Tiny problem with a prompt

[Tomasz Moskal]

On Sat, 2011-07-30 at 15:00 +0200, Mikael Magnusson wrote:

> You need to update PS1 inside precmd(), or use promptsubst and protect
> the parameter expansion.

Brilliant! Updating PS1 in precomd() did the trick. Would you mind
explaining what did you mean by "protecting the parameter expansion" as
the other solution?

Re: Tiny problem with a prompt

[Mikael Magnusson]

On 30 July 2011 15:47, Tomasz Moskal <ramshackle.industries@gmail.com> wrote:
> On Sat, 2011-07-30 at 15:00 +0200, Mikael Magnusson wrote:
>
>> You need to update PS1 inside precmd(), or use promptsubst and protect
>> the parameter expansion.
>
> Brilliant! Updating PS1 in precomd() did the trick. Would you mind
> explaining what did you mean by "protecting the parameter expansion" as
> the other solution?

Either by '$foo' or "\$foo" for example. Ie, put a literal $ sign in
the string. I would prefer updating PS1 in precmd() to setting
promptsubst though.


-- 
Mikael Magnusson