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Notes 20130505

'tc' and 'netem' allow you to simulate some network environments
http://www.linuxfoundation.org/collaborate/workgroups/networking/netem#Delay_distribution
For example, I can delay every packet for 1s, such that in some case I can cheat in games.

Google Chrome complains about "profile cannot be opened correctly"： remove the 'web data' folder in the config dir
http://www.fourleaftechnology.com/index.php/General/google-chrome-profile-could-not-be-opened-correctly-error.html

To remove PDF password with gs
http://www.cyberciti.biz/faq/removing-password-from-pdf-on-linux/
gs -q -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -sOutputFile=unencrypted.pdf -c .setpdfwrite -f encrypted.pdf

IE10 would ignore the `word-spacing` CSS rule if the width for the space char is 0, in a TTF font. Is it a bug of IE?
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