-r, --recursive recurse into directories
-R, --relative use relative path names
-b, --backup make backups (default ~ suffix)
- --backup-dir=DIR put backups in the specified directory
+ --backup-dir make backups into this directory
--suffix=SUFFIX override backup suffix
-u, --update update only (don't overwrite newer files)
-l, --links preserve soft links
--timeout=TIME set IO timeout in seconds
-I, --ignore-times don't exclude files that match length and time
--size-only only use file size when determining if a file should be transferred
+ --modify-window=NUM Timestamp window (seconds) for file match (default=0)
-T --temp-dir=DIR create temporary files in directory DIR
--compare-dest=DIR also compare destination files relative to DIR
-P equivalent to --partial --progress
after using another mirroring system which may not preserve timestamps
exactly.
+dit(bf(--modify-window)) When comparing two timestamps rsync treats
+the timestamps as being equal if they are within the value of
+modify_window. This is normally zero, but you may find it useful to
+set this to a larger value in some situations. In particular, when
+transferring to/from FAT filesystems which cannot represent times with
+a 1 second resolution this option is useful.
+
dit(bf(-c, --checksum)) This forces the sender to checksum all files using
a 128-bit MD4 checksum before transfer. The checksum is then
explicitly checked on the receiver and any files of the same name