alias -g

alias -g

[Eric Smith]

Hi

I define an alias like so:
alias -g T='|translate'

So when I go
$ echo een vreemde taal T

Then zsh will pipe that foreign phrase to a translator.

How do I drop the `echo` with alias -g or something similiar
so all I need to do is go:
$ een vreemde taal T

Thanks a lot.

-- 
- Eric Smith

Re: alias -g

[Alexey I. Froloff]

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On Tue, Aug 03, 2010 at 09:10:28PM +0200, Eric Smith wrote:
> How do I drop the `echo` with alias -g or something similiar
> so all I need to do is go:
> $ een vreemde taal T
You don't need alias:

function T() {
  echo $* | translate
}

$ T een vreemde taal

-- 
Regards,    --
Sir Raorn.   --- http://thousandsofhate.blogspot.com/

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Re: alias -g

[Eric Smith]

Of course

But the nice thing about the alias -g mapping, is that
the command goes at the end.

This is more natural usage and I was wondering if there is a way to do 
this.

-- 
- Eric Smith
Alexey I. Froloff said:
> On Tue, Aug 03, 2010 at 09:10:28PM +0200, Eric Smith wrote:
> > How do I drop the `echo` with alias -g or something similiar
> > so all I need to do is go:
> > $ een vreemde taal T
> You don't need alias:
> 
> function T() {
>   echo $* | translate
> }
> 
> $ T een vreemde taal
> 
> -- 
> Regards,    --
> Sir Raorn.   --- http://thousandsofhate.blogspot.com/

Re: alias -g

[Bart Schaefer]

On Aug 3, 10:02pm, Eric Smith wrote:
> Subject: Re: alias -g
> 
> But the nice thing about the alias -g mapping, is that
> the command goes at the end.
> 
> This is more natural usage and I was wondering if there is a way to do 
> this.

There's no way to do it directly with an alias.  Unlike (t)csh aliases,
zsh aliases cannot manipulate the order of other words in the command.

However, you may be able to get what you want via preexec_functions.

 auto_translate() {
   local -a commandline
   commandline=( ${(z)1} )
   if [[ $commandline[-1] == T ]]
   then
     print -R "${commandline[0,-2]}" | translate
   fi
 }

 # Important that this comes after function definition
 alias -g T='${auto_translate?command execution suppressed}'

 # Set auto_translate to the empty string to both translate
 # and then execute the original command anyway
 unset auto_translate	# Force T alias to abort
 preexec_functions+=( auto_translate )

The trick with ${...?...} is to introduce a failure into the original
command so that it doesn't execute, because the preexec hooks don't
provide a mechanism to gainsay command execution on their own.

Note that this won't work well for compound commands, e.g., if you do

    rm somefile && echo removed somefile T

then you'll see the transation of the entire command line, but the rm
will execute and the echo will not.  There's no way to intercept every
command execution in a compound expression and stop it.

Re: alias -g -> SOLVED

[Eric Smith]

NICE

Thanks Bart

- Eric Smith

> However, you may be able to get what you want via preexec_functions.
> 
>  auto_translate() {
>    local -a commandline
>    commandline=( ${(z)1} )
>    if [[ $commandline[-1] == T ]]
>    then
>      print -R "${commandline[0,-2]}" | translate
>    fi
>  }
> 
>  # Important that this comes after function definition
>  alias -g T='${auto_translate?command execution suppressed}'
> 
>  # Set auto_translate to the empty string to both translate
>  # and then execute the original command anyway
>  unset auto_translate	# Force T alias to abort
>  preexec_functions+=( auto_translate )
> 

Re: alias -g

[Kazuo Teramoto]

On Tue, Aug 3, 2010 at 4:10 PM, Eric Smith <es@fruitcom.com> wrote:
> So when I go
> $ echo een vreemde taal T
[...]
> How do I drop the `echo` with alias -g or something similiar
> so all I need to do is go:
> $ een vreemde taal T

Uhh, I think this can be done for example creating a new autocd like
option, but you gonna need to wait for a better zsh user then me to
show you the code.

But, I think that what you like to do come at a highly price. Because
you loose the very definition of valid command. For example you can
forget that 'rm' is a valid command and type

$ rm important thing T

And get 'important' and 'thing' removed. Ok, rm is not a valid world
in a lot of languages, but what about sleep, wait? Or worse 'unlink'
it is a valid world and can remove your files like rm.

This too can be solved, for example, the new autocd-like function can
check if the last arg is T not if the first arg is a valid command,
but I still think that this can be a shoot in the foot some time.

And for me

$ T een vreemde

is more natural than your syntax, because I read it as "translate 'een
vreemde'". I'm prefer postfix for calculators but for this the prefix
notation is more logical for me.

Regards,
Kazuo

-- 
«Dans la vie, rien n'est à craindre, tout est à comprendre»
Marie Sklodowska Curie.

Re: alias -g

[Kazuo Teramoto]

On Wed, Aug 4, 2010 at 4:22 AM, Kazuo Teramoto <kaz.rag@gmail.com> wrote:
> And get 'important' and 'thing' removed. Ok, rm is not a valid world

Ops. of course I mean word...

-- 
«Dans la vie, rien n'est à craindre, tout est à comprendre»
Marie Sklodowska Curie.