precmd, preexec, and supplied prompt themes

precmd, preexec, and supplied prompt themes

[William Scott]

Hi folks:

I noticed most of the prompt themes use precmd and often preexec.

If either or both of these two functions are defined upstream, they  
get clobbered.

Is there a simple way to prepend or append additional arguments to  
these (or any) functions?  I've been doing something like this, but  
it seems hackish:

precmdarray=( $(which precmd | grep -v precmd | grep -v \}) )


function precmd { $precmdarray  "all the other stuff" }

Thanks.


Bill Scott

Re: precmd, preexec, and supplied prompt themes

[Matthew Wozniski]

On Fri, Oct 12, 2007 at 02:47:23PM -0700, William Scott wrote:
> Is there a simple way to prepend or append additional arguments to these 
> (or any) functions?  I've been doing something like this, but it seems 
> hackish:

Check out the zsh man page, section SPECIAL FUNCTIONS, or just search
for 'hook function'.  The long and short of it is that the prompt
themes should be using

typeset -a precmd_functions
precmd_functions += my_prompt_precmd

and

typeset -a preexec_functions
preexec_functions += my_prompt_preexec

If you're talking about prompt themes supplied with zsh, I would
consider it a bug in the package if those aren't defined that way.

~Matt

Re: precmd, preexec, and supplied prompt themes

[wgscott]

On Fri, 12 Oct 2007 17:59:06 -0400
Matthew Wozniski <godlygeek@gmail.com> wrote:

     On Fri, Oct 12, 2007 at 02:47:23PM -0700, William Scott wrote:
     > Is there a simple way to prepend or append additional arguments to these 
     > (or any) functions?  I've been doing something like this, but it seems 
     > hackish:
     
     Check out the zsh man page, section SPECIAL FUNCTIONS, or just search
     for 'hook function'.  The long and short of it is that the prompt
     themes should be using
     
     typeset -a precmd_functions
     precmd_functions += my_prompt_precmd
     
     and
     
     typeset -a preexec_functions
     preexec_functions += my_prompt_preexec
     
     If you're talking about prompt themes supplied with zsh, I would
     consider it a bug in the package if those aren't defined that way.
     
     ~Matt
     
Thanks.  That seems like a good approach.

These for example all appear to just define a precmd function:

 
prompt_bigfade_setup
 
prompt_elite2_setup
prompt_elite_setup
prompt_fade_setup
prompt_fire_setup
prompt_off_setup
prompt_redhat_setup
prompt_suse_setup
prompt_zefram_setup

The adam1,2, bart and clint ones seem to be doing something else that I suspect is designed to prevent clobbering the function.

Re: precmd, preexec, and supplied prompt themes

[Bart Schaefer]

On Oct 12,  5:59pm, Matthew Wozniski wrote:
}
} themes should be using
} 
} typeset -a precmd_functions
} precmd_functions += my_prompt_precmd
} 
} and
} 
} typeset -a preexec_functions
} preexec_functions += my_prompt_preexec
} 
} If you're talking about prompt themes supplied with zsh, I would
} consider it a bug in the package if those aren't defined that way.

Most of the prompt themes pre-date the existence of the pre*_functions
arrays, and aren't being maintained because their inventors are no longer
zsh-* list participants.

Stomping precmd is the least of the problems with several of those
themes; they rely on now-ancient Linux console fonts for color shading,
assume light-colored text on a dark background, etc.  We need some new
ones.

Re: precmd, preexec, and supplied prompt themes

[William Scott]

Bart Schaefer wrote:
> On Oct 12,  5:59pm, Matthew Wozniski wrote:
> }
> } themes should be using
> }
> } typeset -a precmd_functions
> } precmd_functions += my_prompt_precmd
> }
> } and
> }
> } typeset -a preexec_functions
> } preexec_functions += my_prompt_preexec
> }
> } If you're talking about prompt themes supplied with zsh, I would
> } consider it a bug in the package if those aren't defined that way.
>
> Most of the prompt themes pre-date the existence of the pre*_functions
> arrays, and aren't being maintained because their inventors are no longer
> zsh-* list participants.
>
> Stomping precmd is the least of the problems with several of those
> themes; they rely on now-ancient Linux console fonts for color shading,
> assume light-colored text on a dark background, etc.  We need some new
> ones.
>


OK, here's two:

http://xanana.ucsc.edu/Library/init/zsh/local-functions/general/prompt_kerbaugh_setup

in honor of Gary Kerbaugh, who introduced me to zsh (I'll clean it up for
zsh if you want it), and

http://xanana.ucsc.edu/Library/init/zsh/local-functions/general/prompt_simple_setup

my very own minimalistic/nihilistic theme.

Re: precmd, preexec, and supplied prompt themes

[Bart Schaefer]

On Oct 12,  7:09pm, William Scott wrote:
}
} Bart Schaefer wrote:
} > We need some new ones.
} 
} OK, here's two:

These are fine prompts, but they aren't quite themes, yet.

The prompt_ZZZ_setup file for any theme ZZZ ought to define at least
two functions:

prompt_ZZZ_help
prompt_ZZZ_setup

See Functions/Prompts/prompt_oliver_setup for a simple example.  One
other function may be defined as well:

prompt_ZZZ_preview

See Functions/Prompts/prompt_elite_setup for a short example of that.

Any other prompt_*_function or precmd/preexec are just helpers; the
theme system only uses the above three.

I know, some of the existing themes don't define help or preview, but
that doesn't mean they shouldn't.

Re: precmd, preexec, and supplied prompt themes

[wgscott]

On Fri, 12 Oct 2007 20:27:21 -0700
Bart Schaefer <schaefer@brasslantern.com> wrote:
    
     These are fine prompts, but they aren't quite themes, yet.


Well, that pretty much ensured I wouldn't get any work done this weekend.
     
I've tried to whip my "simple" prompt into shape.  I think it is almost there, but I am
having two difficulties that I am afraid I need to ask help with:

 http://xanana.ucsc.edu/Library/init/zsh/local-functions/general/prompt_simple_setup

The first is that the prompt_simple_preview function doesn't work.

The second, and more fundamental one, is that I can't get the dynamic updating to work
unless I issue these six lines in the shell itself, in addition to the prompt function:

	typeset -a preexec_functions
	preexec_functions+=mypreexec

	typeset -a precmd_functions
	precmd_functions+=myprecmd

	typeset -a chpwd_functions
	chpwd_functions+=mychpwd

After I do that, it all works fine.  But I can't seem to do this from within a function, which leads me to believe I am missing something obvious (that I can't find in the manual -- sorry).

Thanks.

Bill Scott

Re: precmd, preexec, and supplied prompt themes

[Bart Schaefer]

On Oct 13,  1:58pm, wgscott@chemistry.ucsc.edu wrote:
}
} Well, that pretty much ensured I wouldn't get any work done this weekend.

:-)

} The first is that the prompt_simple_preview function doesn't work.

"Doesn't work" how?

Note that the prompt_simple_setup file needs to be found in a directory
in your $fpath to be loaded as a recognized theme by "promptinit".  If
it's not in $fpath, you'll get

% prompt -p simple     

Unknown theme: simple

% 

Is that what's happening?

Also your attempt to display the available colors in prompt_simple_help
is not working for me; "black" compes out white, and neither it nor
"white" are visible on the white background of my xterm.  I'd suggest
restricting the help to bare text and leaving the color demonstrations
to the preview.
 
} The second, and more fundamental one, is that I can't get the dynamic
} updating to work unless I issue these six lines in the shell itself,
} in addition to the prompt function:
} 
} 	typeset -a preexec_functions

Try "typeset -ga preexec_functions" as was pointed out somewhere on this
thread.

Re: precmd, preexec, and supplied prompt themes

[William Scott]

Bart Schaefer wrote:

> } The first is that the prompt_simple_preview function doesn't work.
>
> "Doesn't work" how?

zsh-% prompt_simple_preview
prompt_preview_theme:2: bad pattern: PS1=%B%{^[[39m%}zsh-%# %{^[[39m%}%b

> Also your attempt to display the available colors in prompt_simple_help
> is not working for me; "black" compes out white, and neither it nor
> "white" are visible on the white background of my xterm.  I'd suggest
> restricting the help to bare text and leaving the color demonstrations
> to the preview.

Ok.  (Mine made them grey.)  But it cleverly hides non-viable options from
the user.


> Try "typeset -ga preexec_functions"

That worked.  (I knew it had to be something to do with "global".)

>as was pointed out somewhere on this thread.

Sorry, I somehow missed it.  (Matt just had the -a).

Thanks.

Bill

Re: precmd, preexec, and supplied prompt themes

[Bart Schaefer]

On Oct 13,  2:53pm, William Scott wrote:
}
} zsh-% prompt_simple_preview
} prompt_preview_theme:2: bad pattern: PS1=%B%{^[[39m%}zsh-%# %{^[[39m%}%b

You have 'setopt globsubst', which prompt_preview_theme is not prepared
to deal with.  That should probably be considered a bug.

Re: precmd, preexec, and supplied prompt themes

[William Scott]

Bart Schaefer wrote:
> On Oct 13,  2:53pm, William Scott wrote:
> }
> } zsh-% prompt_simple_preview
> } prompt_preview_theme:2: bad pattern: PS1=%B%{^[[39m%}zsh-%# %{^[[39m%}%b
>
> You have 'setopt globsubst', which prompt_preview_theme is not prepared
> to deal with.  That should probably be considered a bug.
>

Unsetting it masked perhaps another (in promptinit):

zsh-% prompt_simple_preview
simple theme:
prompt_preview_theme:9: command not found: precmd
zsh-% command arg1 arg2 ... argn
prompt_preview_theme:12: command not found: preexec

simple theme with parameters `default yellow green':
prompt_preview_theme:9: command not found: precmd
zsh-% command arg1 arg2 ... argn
prompt_preview_theme:12: command not found: preexec
zsh-%


Sorry for opening this can of worms...

Re: precmd, preexec, and supplied prompt themes

[Bart Schaefer]

On Oct 13,  4:39pm, William Scott wrote:
}
} Sorry for opening this can of worms...

It probably needed opening.


Index: Functions/Prompts/promptinit
===================================================================
RCS file: /extra/cvsroot/zsh/zsh-4.0/Functions/Prompts/promptinit,v
retrieving revision 1.3
diff -c -r1.3 promptinit
--- promptinit	1 Oct 2006 02:38:52 -0000	1.3
+++ promptinit	14 Oct 2007 02:47:52 -0000
@@ -39,6 +39,7 @@
 }
 
 prompt_preview_safely() {
+  emulate -L zsh
   print $reset_color
   if [[ -z "$prompt_themes[(r)$1]" ]]; then
     print "Unknown theme: $1"
@@ -165,6 +166,7 @@
 }
 
 prompt () {
+  emulate -L zsh
   local prompt_opts
   
   set_prompt "$@"
@@ -176,6 +178,7 @@
 }
 
 prompt_preview_theme () {
+  emulate -L zsh
   local -a psv; psv=($psvar); local -a +h psvar; psvar=($psv) # Ick
   local +h PS1=$PS1 PS2=$PS2 PS3=$PS3 PS4=$PS4 RPS1=$RPS1
   trap "${$(functions precmd):-:} ; ${$(functions preexec):-:}" 0
@@ -184,10 +187,10 @@
   (( $#* > 1 )) && print -n " with parameters \`$*[2,-1]'"
   print ":"
   prompt_${1}_setup "$@[2,-1]"
-  precmd
+  typeset +f precmd >&- && precmd
   [[ -o promptcr ]] && print -n $'\r'; :
   print -P "${PS1}command arg1 arg2 ... argn"
-  preexec
+  typeset +f preexec >&- && preexec
 }
 
 [[ -o kshautoload ]] || promptinit "$@"

--