Suppose my mouse suddenly get died while working on a live web page. But my mouse cursor is present there. Now can I move the cursor by keyboard command and , select any option on that web page?
If you indeed want do that from the command line, then you can install xdotool (it is packaged in Ubuntu 16.04 at least) and issue commands like this:
xdotool mousemove 10 500 && xdotool click 1
While not exactly what you want, most applications (including your browser) can be fully controlled by a keyboard. For example, use the
Tab key to jump from a highlighted text to another, type
space to activate a link. With
Pgage Up and
Page Down you can scroll within the page. To access the menu hold
Alt, the underlined letters are the shortcut to activate the corresponding menu. For example
F opens the file menu and then you can navigate the menu with the arrow keys.
That said, if you really need to activate the Mouse Mode, you can do that as described in the wiki.
I don't know what browser are you using, but there is an add-on in mozzila called vimkeybindings, so that will give you a possibility of using vim key to navigate your browser, on crome this tool is called vimium.
This is from the small docs:
About this Add-on Vi(m) directional keybindings for Firefox.
h : scroll left j : scroll down k : scroll up l : scroll right g : go to the top of the page G (shift-g) : go to the bottom of the page
while your mouse in a specific app might be frozen because the app itself is frozen or for other reasons, a simple solution in desktop environment which at least allows you to switch between apps is Alt-Tab. Like mentioned before, if you can't Cntrl-Tab (or similar motions) inside your app, I think probably you won't be able to click with mouse in this app even if you controlled your mouse with keyboard