A friend was recently on a look-out for a camera (DSLR) for a project and was trying various options. Since the residual life of the camera depends on the Shutter Count ; its worth-while to check it before committing to it. BTW, If you need more pointers on evaluating a pre-owned Camera, I would sincerely recommend this video. PS: Language might not be suitable for younger audiences.
On Linux (other platforms too) there is a nice tool called ExifTool which was, as of writing this post available in the package manager of Ubuntu .
sudo apt-get install exiftool
In order to use it, Simply go to the SD Card (generally) and Right Click to open terminal here. Then use the command.
exiftool DSC_0004.JPG |grep "Shutter Count"
Shutter Count should be visible, But depends on the camera you use. Most Nikons we tested had this meta tag in the EXIF(Exchangeable image file format) data of the image, but the only Canon we tested was 1200D which did not show any data.
To know more about EXIF check out this resource .