Does Pandoc follow symlinks when looking for Lua filters?

[jsx97]

Pandoc 3.4, macOS 14.7.1

I have a Lua filter in my Pandoc data directory, which is /Users/jsx/.local/share/pandoc/filters, and it works. Then I moved that filter to my $HOME/scripts directory, which is already added to $PATH, and created a symlink from Pandoc data directory to there:

ln -s $HOME/scripts /Users/jsx/.local/share/pandoc/filters

But It seems that in such a case Pandoc won't see a filter:

cd ~/test
pandoc -o output.md -L my-filter.lua input.htm

Error running filter my-filter.lua:
cannot open my-filter.lua: No such file or directory

Am I correct? (Or maybe I simly don't use symlinks correctly.)

[jgm]

This should work. Doing something similar worked fine for me in a test I just did.
If you do ls -l $HOME/.local/share/pandoc, does filters show up as a symlink?
Do you see the right things with ls $HOME/.local/share/pandoc/filters?

[jsx97]

Here is a detailed walkthrough of what I tried:

1. Make sure the folder /Users/jsx/scripts is added to $PATH.

echo $PATH:

<skipped for brevity>:/Users/jsx/scripts:<skipped for brevity>

2. Make sure the filter is there (that is, in /Users/jsx/scripts).

3. cd to another directory, and run the pandoc command there.

   cd ~/test
   pandoc -o output.md -L filter.lua input.htm
   

   Error running filter filter.lua:
   cannot open filter.lua: No such file or directory
   

And here is an attempt to figure out what is going on:

In Finder, the contents of the /Users/jsx/.local/share/pandoc/filters folder looks like this:

The icon is a symlink to /Users/jsx/scripts.

The output of ls $HOME/.local/share/pandoc/filters is just

scripts

The output of ls -l $HOME/.local/share/pandoc is

total 0
drwxr-xr-x  4 jsx  staff  128 Dec  2 21:43 filters

The output of ls -l $HOME/.local/share/pandoc/filters is

total 0
lrwxr-xr-x  1 jsx  staff  19 Dec  2 21:31 scripts -> /Users/jsx/scripts

[jgm]

OK, looks like you created a symlink within filters to your scripts directory. But pandoc doesn't look in subdirectories of the filters directory. You could try:

rm $HOME/.local/share/pandoc/filters/scripts
rmdir $HOME/.local/share/pandoc/filters
ln -s $HOME/scripts $HOME/.local/share/pandoc/filters

That makes the filters directory point directry to your scripts directory.

Alternatively it may work to do what you did but use -L scripts/filter.lua (untested).

[jsx97]

John, I know you have more important things to do, but I've been trying to figure this out on my own for about two weeks - and haven't had any success yet. Two weeks ago, you suggested me:

rm $HOME/.local/share/pandoc/filters/scripts
rmdir $HOME/.local/share/pandoc/filters
ln -s $HOME/scripts $HOME/.local/share/pandoc/filters

And it worked fine. But then, at some moment, the shell started to complain about missing filters again.

The current output of ls -l $HOME/.local/share/pandoc/filters:

/Users/myname/.local/share/pandoc/filters@ -> /Users/myname/usr

(Here, usr is a custom directory I use for my personal command-line related stuff. It is added it to $PATH, of course.)

Inside usr, I have several pandoc filters, e.g. foo.lua and bar.lua.

Then I do

cd ~/test
pandoc -o output.md -L my-filter.lua input.htm

I receive that "cannot open foo.lua: No such file or directory" error again.

What might be going on here? 🤔

[jgm]

If you do ls ~/.local/share/pandoc/filters, do you see foo.lua?

[jsx97]

Yes.