fuser(1posix) - list process IDs of all processes that have one or more files open 
-c     The  file  is  treated as a mount point and the utility shall report on any files open in the file
       system.
 
-f     The report shall be only for the named files.
 
-u     The user name, in parentheses, associated with each process ID written to standard output shall be
       written to standard error.