c or c++ example of obtaining a specific EXIF datum?

Is there an example you can point me to that shows how to obtain some EXIF value, such as exposure time, from libraw after loading an image? Perhaps there's one in the supplied source code somewhere?

I saw that there are callbacks, but without a specific example, am not clear on how to use them.

Thank you.

Forums: 

Some EXIF/Makernotes fields

Some EXIF/Makernotes fields are parsed in LibRaw, some are not.
Exposure time is available via imgdata.other.shutter

-- Alex Tutubalin