wait_for_xvfb_to_init.sh

# I had a problem today where trying to load things into an Xvfb was not working because the xvfb 
# was not yet initialized. The problem script is as follows:

# Start the Xvfb on DISPLAY :1, 
`dirname $0`/Xvfb :1 -screen 0 1280x1024x24 -ac -br -fbdir /dev/shm & xvfbpid=$!
DISPLAY=:1 xli -onroot -fillscreen `dirname $0`/images/background.png

# The only solution I see on the web is to insert a sleep statement. 
# I don't much like that. The solution I came up with is to wait for the display to be ready to use via xdpyinfo. 
# The working script: 

# Start the Xvfb on DISPLAY :1, 
`dirname $0`/Xvfb :1 -screen 0 1280x1024x24 -ac -br -fbdir /dev/shm & xvfbpid=$!
# Wait for Xvfb to initialize
ACTIVE=9999
while [ $ACTIVE -ne 0 ] ; do
        xdpyinfo -display :1 &> /dev/null
        ACTIVE=$?
done
DISPLAY=:1 xli -onroot -fillscreen `dirname $0`/images/background.png