It would be nice to be able to pass a command-line argument to packmol for specifying the input file just like lammps which support both input redirection and command-line parsing.

The command-line string could look something like this:

packmol -in input.txt

or

packmol -in=input.txt

The intention here is to provide another way of handling input

If you like the feature request I can submit a PR for your review.

With this feature I would be able to run packmol from python via the subprocess command without having to pass a file object for the input file as done in this python script.

I am aware that this feature might not be of great interest to veteran packmol users but it could be of use for new packmol users.