#include "petscsys.h" PetscErrorCode PetscOptionsPrefixPush(PetscOptions options,const char prefix[])Logically Collective
| options | - options database, or NULL for the default global database | |
| prefix | - The string to append to the existing prefix |
| -prefix_push <some_prefix_> | - push the given prefix | |
| -prefix_pop | - pop the last prefix |
-prefix_push system1_ -options_file system1rc -prefix_pop -prefix_push system2_ -options_file system2rc -prefix_pop
where the files no longer require all options to be prefixed with -system2_.
The collectivity of this routine is complex; only the MPI processes that call this routine will have the affect of these options. If some processes that create objects call this routine and others do not the code may fail in complicated ways because the same parallel solvers may incorrectly use different options on different ranks.