[CentOS] CentOS 6 and screenshot of website

Thu Jan 5 15:37:40 UTC 2012
Walter Haidinger <walter at doxlock.com>

Am 05.01.2012 12:52, schrieb John Hodrien:
> So he wants to be able to capture an image of what a website looks like from
> the command line, and not really take a screenshot at all.

Indeed, as there is no screen...

This is diffcult, as websites need to be rendered
and one just has to google for ACID-3 to see that
this not that straightforward.

> I think that's a fair summary anyway...

Yes, thanks for the clarification!

As a workaround, I'd use a "virtual" screen, i.e.
automate the tasks that would have to be done for
a "real" screenshot. This can be scripted without
any user interaction:

* Run Xvnc in the desired resolution/depth
  Sort of a headless X11, debug by connecting via VNC
* setup authentication using xauth (or even xhost if desperate)
* export $DISPLAY to access it
* open the URL to "screenshot" in firefox/chrome/opera, e.g.
  firefox -height x -width y "$url"
  (the -height and -width options still work, right?)
* run xwininfo and grep for the name of the browser window
  to get the windows id
* Screenshot it:
  xwd -id $browserid | xwdtopnm | pnmtojpeg > website.jpg
* kill firefox process
* kill Xvnc if no more screenshots are needed

All steps can also be done manually, therefore
debugging should be easily step by step.

Walter