I know in ubuntu, I can use Screenshot application using which I can take a screen shot for selected window. This means there is the application already on ubuntu. What's the command line command for that application? (I know gnome-screenshot lets us take the whole screenshot, but I want to select a region when taking the shot.)
In order to grab a screenshot of window, use this command
In order to grab an area, use this command
here is the link for source http://manpages.ubuntu.com/manpages/bionic/man1/gnome-screenshot.1.html
-c, --clipboard Send the grab directly to the clipboard. -w, --window Grab the current active window instead of the entire screen. -a, --area Grab an area of the screen instead of the entire screen. -b, --include-border Include the window border within the screenshot. -B, --remove-border Remove the window border from the screenshot. -p, --include-pointer Include the pointer with the screenshot. -d, --delay=SECONDS, Take the screenshot after the specified delay [in seconds]. -e, --border-effect=EFFECT, Add an effect to the outside of the screenshot border. EFFECT can be ``shadow'' (adding drop shadow), ``border'' (adding rectangular space around the screenshot) or ``none'' (no effect). Default is ``none''. -i, --interactive Interactively set options in a dialog. -f, --file=FILENAME Save screenshot directly to this file. --display=DISPLAY X display to use. -?, -h, --help Show a summary of the available options.