Clear Mac OS X's icon cache.

gistfile1.sh

sudo find /private/var/folders/ -name com.apple.dock.iconcache -exec rm {} \;

sudo rm -rfv /Library/Caches/com.apple.iconservices.store; sudo find /private/var/folders/ \( -name com.apple.dock.iconcache -or -name com.apple.iconservices \) -exec rm -rfv {} \; ; sleep 3;sudo touch /Applications/* ; killall Dock; killall Finder
after that restart your mac.
wahlaaah.. all restore and back to normal

This worked really well! Thank you @zigang93.

Works!

Here for better readable and discovering the shell-snippet again:

sudo rm -rfv /Library/Caches/com.apple.iconservices.store; sudo find /private/var/folders/ \( -name com.apple.dock.iconcache -or -name com.apple.iconservices \) -exec rm -rfv {} \; ; sleep 3;sudo touch /Applications/* ; killall Dock; killall Finder

@jasonm23 @andreiborisov i'm interested in changing icons via cli, doing some more debugging, found these articles:

• https://superuser.com/questions/298785/icon-file-on-os-x-desktop
• https://apple.stackexchange.com/questions/6901/how-can-i-change-a-file-or-folder-icon-using-the-terminal

The first one clarifies the 0 bytes size of Icon\r: the file is actually stored in the resource fork

and finally this tool looks promising (although i haven't tested it myself) https://github.com/mklement0/fileicon

EDIT: i tried the tool and it works for me on Monterrey, although i still need to rebuild the cache and restart dock:

rm /var/folders/*/*/*/com.apple.dock.iconcache
killall Dock