Снимок экрана из командной строки

boxcutter [OPTIONS] [OUTPUT_FILENAME] 

 ~~~Saves a screenshot to 'OUTPUT_FILENAME' if given. Only output formats "*.bmp" and "*.png" are supported. If no file name is given, screenshot is stored on clipboard by default. 

~~OPTIONS 
 -c, --coords X1,Y1,X2,Y2 capture the rectange (X1,Y1)-(X2,Y2) 
 -f, --fullscreen fullscreen screenshot 
 -v, --version display version information 
 -h, --help display help message

http://keepnote.org/boxcutter/