3 examples for scrot

  # Take a screenshot with the name YYYY-MM-DD_HH:mm:ss.png and move it to ~/screenshots
scrot '%F_%T.png' -e 'mv $f ~/screenshots/'
        

  # screencap a part of the screen with your mouse
# the file will be titled like 2014-01-31-015810_228x295_scrot.png
scrot -s
        

  # Creates a file called "screenshot.png" after a delay of 10 seconds 
scrot -d 10 screenshot.png