system: using
       a remote‐shell program as the transport (such as ssh or rsh) or contact‐
       ing an rsync daemon directly via TCP.   The  remote‐shell  transport  is
       used whenever the source or destination path contains a single colon (:)
       separator  after  a  host specification.  Contacting an rsync daemon di‐
       rectly happens when the source or destination  path  contains  a  double
       colon (::) separator after a host specification, OR when an rsync:// URL
       is  specified  (see  also  the USING RSYNC‐DAEMON FEATURES VIA A REMOTE‐
       SHELL CONNECTION section for an exception to this latter rule).

       As a special case, if a single source arg is specified without a  desti‐
       nation, the files are listed in an output format similar to "ls -l".

       As  expected, if neither the source or destination path specify a remote
       host, the copy occurs locally (see also the --list‐only option).

       Rsync refers to the local side as the client and the remote side as  the
       server.   Don’t confuse server with an rsync daemon.  A daemon is always
       a server, but a server can be either a daemon or a remote‐shell  spawned
       process.

SETUP
       See the file README.md for installation instructions.

       Once installed, you can use rsync to any machine that you can access via
       a remote shell (as well as some that you can access using the rsync dae‐
       mon‐mode  protocol).   For remote transfers, a modern rsync uses ssh for
       its communications, but it may have been configured to use  a  different
       remote shell by default, such as rsh or remsh.

       You  can  also specify any remote shell you like, either by using the -e
       command line option, or by setting the RSYNC_RSH environment variable.

       Note that rsync must be installed on both the source and destination ma‐
       chines.

USAGE
       You use rsync in the same way you use rcp.  You must  specify  a  source
       and a destination, one of which may be remote.

       Perhaps the best way to explain the syntax is with some examples:

           rsync ‐t *.c foo:src/

       This  would transfer all files matching the pattern *.c from the current
       directory to the directory src on the machine foo.  If any of the  files
       already exist on the remote system then the rsync remote‐update protocol
       is  used to update the file by sending only the differences in the data.
       Note that the expansion of wildcards on the command‐line  (*.c)  into  a
       list  of  files  is handled by the shell before it runs rsync and not by
       rsync itself (exactly the same as all other Posix‐style programs).

           rsync ‐avz foo:src/bar /data/tmp

       This would recursively transfer all files from the directory src/bar  on
       the  machine  foo into the /data/tmp/bar directory on the local machine.
       The files are transferred in archive mode, which ensures  that  symbolic
       links,  devices, attributes, permissions, ownerships, etc. are preserved
       in the transfer.  Additionally, compression will be used to  reduce  the
       size of data portions of the transfer.

           rsync ‐avz foo:src/bar/ /data/tmp

       A  trailing  slash on the source changes this behavior to avoid creating
       an additional directory level at the destination.  You can  think  of  a
       trailing  / on a source as meaning "copy the contents of this directory"
       as opposed to "copy the directory by name", but in both  cases  the  at‐
       tributes  of  the containing directory are transferred to the containing
       directory on the destination.  In other words,  each  of  the  following
       commands  copies  the  files in the same way, including their setting of
       the attributes of /dest/foo:

           rsync ‐av /src/foo /dest
           rsync ‐av /src/foo/ /dest/foo

       Note also that host and module references don’t require a trailing