Mac guide

adjust voice volume
a）shit + option + voice
b）in the terminal :

sudo osascript -e "set Volume 0.01"

vi  ~/.bash_profile and write

osascript -e "set Volume 0.01"

and save.
sudo chmod 700  ~/.bash_profile
source ~/.bash_profile

view pdf from terminal
open <filename.pdf>
open -a Preview.app <filename.pdf>

update mac os without ID
     download the installer from the Web by visiting this link on Apple Support website. Then copy the installer to the Applications folder. Double click on the application and you will be able to install the update.  


chang scroll direction
https://www.apple.com/shop/question/answers/readonly/how-to-change-scroll-direction/Q97XDXY9PFJACCDCT 


brew install without update

export HOMEBREW_NO_AUTO_UPDATE=1




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