Collapse a file path to the shortest representation

Collapse a file path to the shortest representation

[Zach Riggle]

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Is there a ZSH standard way to collapse a file path to its shortest
representation that would be idempotent per Chapter 14.7?

For example, one might

echo "$filepath" | sed -E "s|$HOME/?|~/|"
echo "$filepath" | sed -E "s|$HOME/?|\$HOME/|"


In order to turn

/home/username/bar/baz → ~/bar/baz
/home/username/bar/baz → $HOME/bar/baz


To achieve this effect.

From the documentation, "14.7 Filename Expansion" has a lot of ways that
paths can be expanded, including...

14.7.2
... the path is checked to see if it has a named directory as its prefix.
If so, then the prefix portion is replaced with a ‘~’ followed by the name
of the directory ....


Is there a standardized way to access this expansion with e.g.
/path/to/somedir → ~SOMEDIR/foo?

I expect this can be implemented manually by parsing the output of "hash
-d" or similar, but I figured it was worth asking if there's an easy
interface to this.

I'm not concerned as much about "14.7.1 Dynamic named directories" but for
completeness it would be neat.

*Zach Riggle*

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Re: Collapse a file path to the shortest representation

[Mikael Magnusson]

On 5/13/22, Zach Riggle <zachriggle@gmail.com> wrote:
> Is there a ZSH standard way to collapse a file path to its shortest
> representation that would be idempotent per Chapter 14.7?
>
> For example, one might
>
> echo "$filepath" | sed -E "s|$HOME/?|~/|"
> echo "$filepath" | sed -E "s|$HOME/?|\$HOME/|"
>
>
> In order to turn
>
> /home/username/bar/baz → ~/bar/baz
> /home/username/bar/baz → $HOME/bar/baz
>
>
> To achieve this effect.
>
> From the documentation, "14.7 Filename Expansion" has a lot of ways that
> paths can be expanded, including...
>
> 14.7.2
> ... the path is checked to see if it has a named directory as its prefix.
> If so, then the prefix portion is replaced with a ‘~’ followed by the name
> of the directory ....
>
>
> Is there a standardized way to access this expansion with e.g.
> /path/to/somedir → ~SOMEDIR/foo?

The D parameter expansion flag does this.

-- 
Mikael Magnusson

Re: Collapse a file path to the shortest representation

[Zach Riggle]

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Thanks! It does indeed.

Is there a way to specify appearance?  ~ENV vs $ENV

        ~SOME_ENV_VAR/foo/bar
        $SOME_ENV_VAR/foo/bar

*Zach Riggle*


On Fri, May 13, 2022 at 1:03 PM Mikael Magnusson <mikachu@gmail.com> wrote:

> On 5/13/22, Zach Riggle <zachriggle@gmail.com> wrote:
> > Is there a ZSH standard way to collapse a file path to its shortest
> > representation that would be idempotent per Chapter 14.7?
> >
> > For example, one might
> >
> > echo "$filepath" | sed -E "s|$HOME/?|~/|"
> > echo "$filepath" | sed -E "s|$HOME/?|\$HOME/|"
> >
> >
> > In order to turn
> >
> > /home/username/bar/baz → ~/bar/baz
> > /home/username/bar/baz → $HOME/bar/baz
> >
> >
> > To achieve this effect.
> >
> > From the documentation, "14.7 Filename Expansion" has a lot of ways that
> > paths can be expanded, including...
> >
> > 14.7.2
> > ... the path is checked to see if it has a named directory as its prefix.
> > If so, then the prefix portion is replaced with a ‘~’ followed by the
> name
> > of the directory ....
> >
> >
> > Is there a standardized way to access this expansion with e.g.
> > /path/to/somedir → ~SOMEDIR/foo?
>
> The D parameter expansion flag does this.
>
> --
> Mikael Magnusson
>

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