- `S = functions (FCN_HANDLE)`

Return a structure containing information about the function handle
`FCN_HANDLE`.

The returned structure describes the function name, type, source file when
available, and additional implementation details.

This function is intended for debugging and introspection.

See also: `func2str`, `str2func`.

### References

- https://www.mathworks.com/help/matlab/ref/functions.html
- https://octave.sourceforge.io/octave/function/functions.html