Subject: Re: [GSoC] microporject test_path_is_*

From: Ævar Arnfjörð Bjarmason <[email-masked]>
Date: Wed, 27 Mar 2019 12:21:55 +0100

On Wed, Mar 27 2019, SZEDER Gábor wrote:

> On Wed, Mar 27, 2019 at 11:09:18AM +0100, Ævar Arnfjörð Bjarmason wrote:
>> > There are likewise several that use one of
>> >    ! test -e path/to/filename
>> > or
>> >    ! test -f path/to/filename
>> > or
>> >   test ! -f path/to/filename
>> > which could be replaced by
>> >   test_path_is_missing path/to/filename
>>
>> Interesting that for some we use the 'test_is_there/test_is_not_there'
>> pattern and for others 'test_is_there [!]'. E.g
>> test_path_exist/test_path_is_missing v.s. test_i18ngrep.
>
> It's unclear what the '!' should negate in case of 'test_path_is_file
> ! file'.  What if 'file' does exists, but it's not a file but a
> directory, socket, fifo, or symlink?  'test ! -f file' returns success
> in these cases as well.
>
> OTOH, it's quite clear what the negation should mean in case of
> 'test_i18ngrep'.

*Should* we make it better? Yeah sure, maybe. I'm just pointing out for
context to someone poking at this for the first time that now we
sometimes do "! foo <arg>" v.s. "foo <arg>" as "foo_is <arg>" and
"foo_not <arg>" and other times "foo [!] <arg>".

So yeah, maybe we should improve things to disambiguate the cases you
mentioned, but right now e.g. "test_path_exists" and
"test_path_is_missing" are just "test -e" and "! test -e", respectively.

The same caveats you've mentioned also apply to "test_i18ngrep" b.t.w.,
there we squash the 3x standard exit codes of grep[1] into a boolean,
and thus e.g. ignore the difference between <file> not matching an
<file> being a directory or whatever.

1. http://pubs.opengroup.org/onlinepubs/009695399/utilities/grep.html