macOS / binaries /

lsof

/usr/sbin/lsof
List open files

lsof revision 4.91 lists on its standard output file information about files opened by processes. An open file may be a regular file, a directory, a block special file, a character special file, an executing text reference, a library, a stream or a network file (Internet socket, NFS file or UNIX domain socket.)

source: man