/usr/share/dune-grid/grids/dgf/simplex-testgrid-1-1.dgf is in libdune-grid-dev 2.5.1-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 | DGF
Vertex
0.0
0.25
0.5
0.75
1.0
#
Simplex
0 1
1 2
2 3
3 4
#
BoundaryDomain
default 1
#
|