Several Mac OS X tips

1. Getting tired of the default background of login window? You can change it by

# sudo defaults write \
  /Library/Preferences/com.apple.loginwindow \
  DesktopPicture '/Path/To/Your/Picture'

2. Set default path for every application in Mac OS X:

# mkdir ~/.MacOSX
# defaults write ~/.MacOSX/environment "PATH"  $PATH

Log out then log in and you are all set. You can also use this method for other shell variables.

3. When you use spotlight to search content of PDF files, clicking on the result will bring up Preview.app, showing the highlighted text at a very large scale, effectively rendering this feature useless. To change it,

# defaults write com.apple.Preview Preview \
  -dict-add PVPDFSpotlightSelectionSize 1