Re: PATCH: relpath

[Jim Meyering]

Pádraig Brady wrote:
...
>> Reading only the documentation for --relative-base=FILE,
>> I am not sure how it works:
>>
>> `--relative-base=FILE'
>>      Ensure both the `--relative-to' and processed files are
>>      subdirectories of FILE, or otherwise output the absolute file name.
>>      Note this option honors the `-m' and `-e' options pertaining to
>>      file existence.
>>
>> An example or two would help a lot.
>
> I'll add something along these lines:

Thanks.

> $ realpath --relative-to=/usr /tmp /usr/bin
> ../tmp

I see two lines of output.  I guess you missed the latter?

    $ ./realpath --relative-to=/usr /tmp /usr/bin
    ../tmp
    bin

> $ realpath --relative-base=/usr --relative-to=/usr /tmp /usr/bin
> /tmp
> bin

Good.  That makes it clearer.
The "Ensure" threw me.  It's not really ensuring it.
Maybe something like this?

   `--relative-base=BASE'
        When both the `--relative-to' file and a listed FILE are
        descendants of BASE, print a BASE-relative name for FILE.
        Otherwise, print FILE's absolute name.
        Note this option honors the `-m' and `-e' options pertaining to
        file existence.

There's probably more to consider when the --relative-to= and
--relative-base= specified names are different, but I haven't
thought about that.