Re: Conditional newline in prompt

["Benjamin R. Haskell" <zsh@xxxxxxxxxx>]

On Wed, 1 Dec 2010, Christoph Wurm wrote:

> Hello,
>
> I would like to display the exit code of a command if it is not 0 on a 
> line of its own, followed by the prompt on the next line.
>
> Is this possible?
>
> I was able to come up with the following:
>
> PROMPT="%0(?..%?)
> %{$fg[green]%}%n@%m%{$reset_color%}:%~ %{$fg[red]%}%#%{$reset_color%} "
>
> However, this prints a newline after every command. Is there some 
> equivalent of '\n' that can be used inside the conditional substring? 
> Or some other way to do this?

Just put the portion that you want to be conditional inside the parens:

You had:
PROMPT="%0(?..%?)
%{$fg[green]%}%n@%m%{$reset_color%}:%~ %{$fg[red]%}%#%{$reset_color%} "

Instead use:
PROMPT="%0(?..%?
)%{$fg[green]%}%n@%m%{$reset_color%}:%~ %{$fg[red]%}%#%{$reset_color%} "

You also don't need the '0' in '%0', since it's the default, so:
PROMPT="%(?..%?
)%{$fg[green]%}%n@%m%{$reset_color%}:%~ %{$fg[red]%}%#%{$reset_color%} "

Adding in my personal preferences, and the following facts:
1. I prefer $''-style quoting when newlines are involved.
2. Parameter expansion is handled as part of prompt expansion.
3. The lone number sitting on a line by itself seems weird.

I might use:
PROMPT=$'%(?..%{$fg[red]%}error=%?%{$reset_color%}\n)%{$fg[green]%}%n@%m%{$reset_color%}:%~ %{$fg[red]%}%#%{$reset_color%} '

--
Best,
Ben