[Gmsh] Periodic boundary

[Jehanzeb Hameed]

Hello,

I am trying to create a 3-D cube mesh, such that the opposite faces
along x and y directions have identical surface meshes, which will be
useful for me to implement periodic boundary conditions. Is there a
way to do this in gmsh?

Note that there will be other stuff in the interior of the cube, e.g.
a cylinder, that will also need to be meshed. I know how to create a
mesh such that the cube and the cylinder which runs through it is
meshed, but I dont know how to create periodic (or similar) surface
meshes at opposite faces of the cube.

Thanks,
-Jehanzeb