So, el capitan has a new binary called sfltool. It has been discussed a few times, and I have incorporated it into my firstrun script to add items to the sidebar. I think many more uses for this will be discovered.
Here is my script as an example.
#!/bin/bash
# Get the Username of the currently logged user
loggedInUser=`/bin/ls -l /dev/console | /usr/bin/awk '{ print $3 }'`
if [ -e /usr/local/bin/mysides ]
then
su - "$loggedInUser" -c "/usr/local/bin/mysides remove All My Files file:///System/Library/CoreServices/Finder.app/Contents/Resources/MyLibraries/myDocuments.cannedSearch/" && sleep 2
su - "$loggedInUser" -c "/usr/local/bin/mysides remove iCloud x-apple-finder:icloud" && sleep 2
su - "$loggedInUser" -c "/usr/local/bin/mysides remove domain-AirDrop nwnode://domain-AirDrop" && sleep 2
/usr/bin/sfltool add-item com.apple.LSSharedFileList.FavoriteItems file:///Users/$loggedInUser && sleep 2
/usr/bin/sfltool add-item com.apple.LSSharedFileList.FavoriteItems file:///Users/$loggedInUser/Desktop && sleep 2
/usr/bin/sfltool add-item com.apple.LSSharedFileList.FavoriteItems file:///Users/$loggedInUser/Documents && sleep 2
/usr/bin/sfltool add-item com.apple.LSSharedFileList.FavoriteItems file:///Users/$loggedInUser/Downloads && sleep 2
/usr/bin/sfltool add-item com.apple.LSSharedFileList.FavoriteItems file:///Users/$loggedInUser/Movies && sleep 2
/usr/bin/sfltool add-item com.apple.LSSharedFileList.FavoriteItems file:///Users/$loggedInUser/Music && sleep 2
/usr/bin/sfltool add-item com.apple.LSSharedFileList.FavoriteItems file:///Users/$loggedInUser/Pictures && sleep 2
touch /Users/$loggedInUser/.sidebarshortcuts
fi
/usr/libexec/PlistBuddy -c "Add :networkbrowser:CustomListProperties:com.apple.NetworkBrowser.backToMyMacEnabled bool False" /Users/$loggedInUser/Library/Preferences/com.apple.sidebarlists.plist
/usr/libexec/PlistBuddy -c "Add :networkbrowser:CustomListProperties:com.apple.NetworkBrowser.bonjourEnabled bool False" /Users/$loggedInUser/Library/Preferences/com.apple.sidebarlists.plist
killall cfprefsd
