Examples Setting the user immutable ( uchg ) flag for a file prevents it from being deleted, changed, or moved. By locking a file in the Finder, you're actually setting its user immutable flag. There- fore, this command locks the file as well: chflags uchg importantfile.doc Unset the user immutable flag and thus unlock the file: chflags nouchg importantfile.doc chgrp chgrp [options] newgroup files Changes the ownership of one or more files to newgroup. newgroup is either a group ID number or a group name known to directory services. You must own the file or be a privileged user to succeed with this command. Options