a fast, versatile, remote (and local) file-copying tool

-r, --recursive
       This tells rsync to copy directories recursively.  See also --dirs (-d).

       Beginning with rsync 3.0.0, the recursive algorithm used is now an incremental scan that uses much
       less memory than before and begins the transfer after the scanning of the  first  few  directories
       have  been  completed.   This  incremental scan only affects our recursion algorithm, and does not
       change a non-recursive transfer.  It is also only possible when both ends of the transfer  are  at
       least version 3.0.0.

       Some  options  require  rsync to know the full file list, so these options disable the incremental
       recursion  mode.   These  include:  --delete-before,   --delete-after,   --prune-empty-dirs,   and
       --delay-updates.   Because  of  this,  the  default  delete  mode when you specify --delete is now
       --delete-during when both ends of the connection are at least 3.0.0 (use --del or  --delete-during
       to  request this improved deletion mode explicitly).  See also the --delete-delay option that is a
       better choice than using --delete-after.

       Incremental recursion can be disabled using the --no-inc-recursive option or its shorter  --no-i-r
       alias.

-v, --verbose
       This  option  increases  the amount of information you are given during the transfer.  By default,
       rsync works silently. A single -v will give you information about what files are being transferred
       and  a  brief summary at the end. Two -v options will give you information on what files are being
       skipped and slightly more information at the end. More than two -v options should only be used  if
       you are debugging rsync.

       Note that the names of the transferred files that are output are done using a default --out-format
       of "%n%L", which tells you just the name of the file and, if the item is a link, where it  points.
       At  the  single  -v  level  of  verbosity,  this  does not mention when a file gets its attributes
       changed.  If you ask for an itemized list  of  changed  attributes  (either  --itemize-changes  or
       adding  "%i"  to  the  --out-format  setting), the output (on the client) increases to mention all
       items that are changed in any way.  See the --out-format option for more details.

-t, --times
       This tells rsync to transfer modification times along with the files and update them on the remote
       system.   Note that if this option is not used, the optimization that excludes files that have not
       been modified cannot be effective; in other words, a missing -t or -a will cause the next transfer
       to  behave  as  if  it  used  -I,  causing  all files to be updated (though rsync’s delta-transfer
       algorithm will make the update fairly efficient if the files haven’t actually changed, you’re much
       better off using -t).

-l, --links
       When symlinks are encountered, recreate the symlink on the destination.

-d, --dirs
       Tell the sending side to include any directories that  are  encountered.   Unlike  --recursive,  a
       directory’s  contents  are  not  copied  unless the directory name specified is "." or ends with a
       trailing slash (e.g. ".", "dir/.", "dir/", etc.).  Without this option or the --recursive  option,
       rsync  will skip all directories it encounters (and output a message to that effect for each one).
       If you specify both --dirs and --recursive, --recursive takes precedence.

       The --dirs option is implied by the --files-from option or the --list-only  option  (including  an
       implied  --list-only  usage)  if --recursive wasn’t specified (so that directories are seen in the
       listing).  Specify --no-dirs (or --no-d) if you want to turn this off.

       There is also a backward-compatibility helper option, --old-dirs (or --old-d) that tells rsync  to
       use  a  hack  of  "-r  --exclude=’/*/*’"  to get an older rsync to list a single directory without
       recursing.

-g, --group
       This option causes rsync to set the group of the destination file to be the  same  as  the  source
       file.  If the receiving program is not running as the super-user (or if --no-super was specified),
       only groups that the invoking user on the receiving  side  is  a  member  of  will  be  preserved.
       Without  this  option, the group is set to the default group of the invoking user on the receiving
       side.

       The preservation of group information will associate matching names by default, but may fall  back
       to  using  the  ID  number  in  some  circumstances  (see also the --numeric-ids option for a full
       discussion).

-o, --owner
       This option causes rsync to set the owner of the destination file to be the  same  as  the  source
       file,  but  only  if  the receiving rsync is being run as the super-user (see also the --super and
       --fake-super options).  Without this option, the owner of new and/or transferred files are set  to
       the invoking user on the receiving side.

       The preservation of ownership will associate matching names by default, but may fall back to using
       the ID number in some circumstances (see also the --numeric-ids option for a full discussion).

-D     The -D option is equivalent to --devices --specials.