PETSc version 3.16.6

PetscViewerRegister

Adds a viewer

#include "petscviewer.h" 
PetscErrorCode  PetscViewerRegister(const char *sname,PetscErrorCode (*function)(PetscViewer))

Not Collective

	name_solver	- name of a new user-defined viewer
	routine_create	- routine to create method context

PetscViewerRegister() may be called multiple times to add several user-defined viewers.

   PetscViewerRegister("my_viewer_type",MyViewerCreate);

Then, your solver can be chosen with the procedural interface via

    PetscViewerSetType(viewer,"my_viewer_type")

or at runtime via the option

    -viewer_type my_viewer_type

developer