Re: Check existence but not dereference symlink

[Andreas Kusalananda Kähäri]

On Fri, Mar 26, 2021 at 04:17:06PM -0500, Peng Yu wrote:
> Hi,
> 
> ln -s 1.txt a.txt
> [[ -a a.txt ]]; echo $?
> 1
> [[ -e a.txt ]]; echo $?
> 1
> 
> [[ -e path ]] and [[ -e path ]] will deference symlink. If the target
> does not exist, it will return an error.
> 
> I want to check the existence of a path without dereferencing symlink.
> I come up with this, but it is a little verbose. Is this the best way
> to do so?
> 
> [[ -f path || -h path || -d path ]]
> 
> -- 
> Regards,
> Peng

I would have thought

        [[ -h path ]] || [[ -e path ]]

would be enough.  This tests whether "path" is a symbolic link, and if
it's not, whether it exists.

With your expression, you're definitely dereferencing
the possible symbolic link at "path" to see whether its target is a
regular file before testing whether it's a symbolic link.  (I'm also not
sure why you use -f and -d as it could potentially be any filetype.)


-- 
Andreas (Kusalananda) Kähäri
SciLifeLab, NBIS, ICM
Uppsala University, Sweden

.