I have a video headlight for my bike and occasionally I want to lock a file to make sure it’s not written over with subsequent videos. Later I want to unlock them. One way is to reformat the memory card. Another way is to do it on theMac. However, Finder does not indicate which files are locked. This unix command can be used:
Start the Terminal
cd to the proper folder. I moved to the top level, then to Volumes, then to the volume with the memory card which is inserted into the MacBook Thunderbolt port.
“sudo find . -flags uchg” [without the quotes. This will list locked files. To unlock files, use: “sudo chflags -R nouchg”]