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Kapil Hari Paranjape [kapil at imsc.res.in]
Hello,
I had to do this to debug a program so I thought I'd share it.
X window dump without X
How does one take a screenshot without X? (For example, from the text console)
Use Xvfb (the X server that runs on a virtual frame buffer).
Steps:
1. Run Xvfb
$ Xvfb
This will usually start the X server :99
$ DISPLAY=:99 ; export DISPLAY
2. Run your application in the appropriate state.
$ firefox https://www.linuxgazette.net &
3. Find out which window id corresponds to your application
$ xwininfo -name 'firefox-bin' | grep id
Or
$ xlsclients
Use the hex string that you get as window id in the commands
below
4. Dump the screen shot of that window
$ xwd -id 'hexid" > firefox.xwd
5. If you want to, then kill these applications along with the
X server
$ killall Xvfb
'firefox.xwd' is the screenshot you wanted. Use 'convert' or on of the netpbm tools to convert the 'xwd' format to 'png' or whatever.
Additional Notes:
A. You can use a different screenshot program.
B. If you need to manipulate the window from the command line, then programmes like 'xautomation' and/or 'xwit' are your friends. Alternatively, use a WM like "fvwm" or "xmonad":
DISPLAY=:99 xmonad &This will allow you to manipulate windows from the command line if you know some Haskell!
Regards,
Kapil. --
Thomas Adam [thomas.adam22 at gmail.com]
2009/3/21 Kapil Hari Paranjape <kapil@imsc.res.in>:
> Hello, > > I had to do this to debug a program so I thought I'd share it. > > X window dump without X > ----------------------- > > How does one take a screenshot without X? (For example, from the text > console) > > Use Xvfb (the X server that runs on a virtual frame buffer).
Or just use Xephyr. In fact this would be even easier, since there's an additional overhead in using Xvfb.
-- Thomas Adam
Kapil Hari Paranjape [kapil at imsc.res.in]
Hello,
On Sat, 21 Mar 2009, Thomas Adam wrote:
> 2009/3/21 Kapil Hari Paranjape <kapil@imsc.res.in>: > > Use Xvfb (the X server that runs on a virtual frame buffer). > > Or just use Xephyr. In fact this would be even easier, since there's > an additional overhead in using Xvfb.
I thought Xephyr cannot create a virtual display (for example if you are in a text console).
I agree that Xephyr would be better if you want to run this inside an existing X session.
Regards,
Kapil. --