[GTALUG] Bash does-directory-exist question

[Giles Orr]

On Fri, 10 Jul 2020 at 11:11, David Mason <dmason at ryerson.ca> wrote:
>
> (base) : ~/foo ; [ -w .. ] && echo true
> true
> (base) : ~/foo ; /bin/pwd
> pwd: .: No such file or directory
> (base) : ~/foo ; pwd
> /Users/dmason/foo
> (base) : ~/foo ; [ -w $PWD ] && echo true
> (base) : ~/foo ;
>
> So, /bin/pwd fails and [ -w $PWD ] also fails, as John hypothesized
>
> ../Dave
> On Jul 10, 2020, 11:01 AM -0400, John Sellens via talk <talk at gtalug.org>, wrote:
>
> On Fri, 2020/07/10 09:38:48AM -0400, Giles Orr via talk <talk at gtalug.org> wrote:
> | This gives immediate visual feedback on the write-status of the
> | current directory. But test's '-w' and '-d' both claim that you're
> | still in a valid directory under the above circumstances. Does anyone
> | know of a simple way to find out if the directory you're currently in
> | actually exists?
>
> The directory "." will still exist while you have it open (your current
> directory), but will be unreachable, as you observed with stat(1) and
> the number of links.
>
> Would checking for "test -d $PWD" work? I think $PWD is the full path
> and so if it's no longer reachable, the test should fail?
>
> Hope that helps

I love this list!  I thought that '[ -w . ]' and '[ -w $PWD ]' were
practically equivalent.  "Practically" means, in this case, "almost."
But not quite - and the difference is the solution to the problem.
Thanks everyone, particularly John and Dave.

-- 
Giles
https://www.gilesorr.com/
gilesorr at gmail.com