$ gemmi contents -h
Usage:
 gemmi contents [options] INPUT[...]
Analyses content of a PDB or mmCIF.
  -h, --help     Print usage and exit.
  -V, --version  Print version and exit.
  -v, --verbose  Verbose output.
  --select=SEL   Use only the selection.
  -b             Print statistics of isotropic ADPs (B-factors).
  --dihedrals    Print peptide dihedral angles.
  -n             Do not print content (for use with other options).
