Getting FEniCS to communicate with gmsh

1

I need to call gmsh from my python script. I am using gmsh 4.4.1, Python 2.7.18.
I haven’t tried this before. So decided to go through some old posts regarding this. But since I am not familiar with this, having some issue understanding some of the things in those posts.

For example, in the post

https://fenicsproject.discourse.group/t/adaptive-remeshing-with-mmg-and-xmdf-msh-conversion/3832

what are the functions of the following lines of codes?

fname = "plate"
subprocess.call(["gmsh", fname+".geo", "-2", "-format", "msh2"])
subprocess.call(["meshio-convert", fname+".msh", fname+".xdmf", "-p", "-z"])

More specifically, what do “-2”, “-format”, “msh2”, “-p” and “-z” mean and what they do?

Also what does “subprocess.call” do?

2

These questions are unrelated to FEniCS. It’s pretty straightforward to look up the documentation for these other libraries and inbuilt python functions with a quick web search. E.g. subprocess.call.