Implement CDPATH mechanism in Zsh script

Implement CDPATH mechanism in Zsh script

[Sebastian Gniazdowski]

Hello,
I need to determine how CWD changed after: cd "not-absolute-path" –
and do this in Zsh script. How to re-implement that mechanism in
script? Any neat tricks or maybe an official way?

Best regards,
Sebastian Gniazdowski

Re: Implement CDPATH mechanism in Zsh script

[Bart Schaefer]

On Sep 3, 11:52pm, Sebastian Gniazdowski wrote:
}
} I need to determine how CWD changed after: cd "not-absolute-path" -
} and do this in Zsh script. How to re-implement that mechanism in
} script? Any neat tricks or maybe an official way?

Do you mean something other than comparing $OLDPWD to $PWD ?

Or are you trying to predict how the current directory is going to be
changed by "cd", without actually executing "cd"?

Re: Implement CDPATH mechanism in Zsh script

[Sebastian Gniazdowski]

[-- Attachment #1: Type: text/plain, Size: 335 bytes --]

On 7 September 2016 at 08:04, Bart Schaefer <schaefer@brasslantern.com>
wrote:

> Do you mean something other than comparing $OLDPWD to $PWD ?
>
> Or are you trying to predict how the current directory is going to be
> changed by "cd", without actually executing "cd"?
>

Ah, it's about prediction

Best regards,
Sebastian Gniazdowski

Re: Implement CDPATH mechanism in Zsh script

[Bart Schaefer]

On Sep 7,  8:13am, Sebastian Gniazdowski wrote:
}
} On 7 September 2016 at 08:04, Bart Schaefer <schaefer@brasslantern.com>
} wrote:
} 
} > Or are you trying to predict how the current directory is going to be
} > changed by "cd", without actually executing "cd"?
} 
} Ah, it's about prediction

The most obvious/foolproof thing would be to use a subshell:

    newPWD=$(cd -q $where >&/dev/null && pwd)

Next would be globbing:

    # Assumes last component of $cdpath is "."
    cdWD=( $^cdpath/$where(N[1]) )
    newPWD=${cdWD:A}

Note this is exactly what :A is supposed to be for, but it gives the
wrong result if CHASE_LINKS or CHASE_DOTS is set, so you may need the
new :P modifier, or the :a modifier instead.  [[ -o ... ]] tests left
as an exercise.