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NAME
rsync - faster, flexible replacement for rcp

SYNOPSIS
rsync [OPTION]... SRC [SRC]... [USER@]HOST:DEST

rsync [OPTION]... [USER@]HOST:SRC DEST

rsync [OPTION]... SRC [SRC]... DEST

rsync [OPTION]... [USER@]HOST::SRC [DEST]

rsync [OPTION]... SRC [SRC]... [USER@]HOST::DEST

rsync [OPTION]... rsync://[USER@]HOST[:PORT]/SRC [DEST]

rsync [OPTION]... SRC [SRC]... rsync://[USER@]HOST[:PORT]/DEST

DESCRIPTION
rsync is a program that behaves in much the same way that rcp does,
but has many more options and uses the rsync remote-update protocol to
greatly speed up file transfers when the destination file is being
updated.

The rsync remote-update protocol allows rsync to transfer just the
differences between two sets of files across the network connection,
using an efficient checksum-search algorithm described in the techni-
cal report that accompanies this package.

Some of the additional features of rsync are:

o support for copying links, devices, owners, groups, and permis-
sions

o exclude and exclude-from options similar to GNU tar

o a CVS exclude mode for ignoring the same files that CVS would
ignore

o can use any transparent remote shell, including ssh or rsh

o does not require root privileges

o pipelining of file transfers to minimize latency costs

o support for anonymous or authenticated rsync servers (ideal for
mirroring)

GENERAL
There are eight different ways of using rsync. They are:

o for copying local files. This is invoked when neither source
nor destination path contains a : separator

o for copying from the local machine to a remote machine using a
remote shell program as the transport (such as ssh or rsh).
This is invoked when the destination path contains a single :
separator.

o for copying from a remote machine to the local machine using a
remote shell program. This is invoked when the source contains
a : separator.

o for copying from a remote rsync server to the local machine.
This is invoked when the source path contains a :: separator or
an rsync:// URL.

o for copying from the local machine to a remote rsync server.
This is invoked when the destination path contains a :: separa-
tor or an rsync:// URL.

o for copying from a remote machine using a remote shell program
as the transport, using rsync server on the remote machine.
This is invoked when the source path contains a :: separator
and the --rsh=COMMAND (aka "-e COMMAND") option is also pro-
vided.

o for copying from the local machine to a remote machine using a
remote shell program as the transport, using rsync server on
the remote machine. This is invoked when the destination path
contains a :: separator and the --rsh=COMMAND option is also
provided.

o for listing files on a remote machine. This is done the same
way as rsync transfers except that you leave off the local des-
tination.

Note that in all cases (other than listing) at least one of the source
and destination paths must be local.

SETUP
See the file README 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 daemon-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.

One common substitute is to use ssh, which offers a high degree of
security.

Note that rsync must be installed on both the source and destination
machines.

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 cur-
rent 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.
See the tech report for details.

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 direc-
tory" as opposed to "copy the directory by name", but in both cases
the attributes of the containing directory are transferred to the con-
taining 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

You can also use rsync in local-only mode, where both the source and
destination don't have a ':' in the name. In this case it behaves like
an improved copy command.

rsync somehost.mydomain.com::

This would list all the anonymous rsync modules available on the host
somehost.mydomain.com. (See the following section for more details.)

ADVANCED USAGE
The syntax for requesting multiple files from a remote host involves
using quoted spaces in the SRC. Some examples:

rsync host::'modname/dir1/file1 modname/dir2/file2' /dest

This would copy file1 and file2 into /dest from an rsync daemon. Each
additional arg must include the same "modname/" prefix as the first
one, and must be preceded by a single space. All other spaces are
assumed to be a part of the filenames.

rsync -av host:'dir1/file1 dir2/file2' /dest

This would copy file1 and file2 into /dest using a remote shell. This
word-splitting is done by the remote shell, so if it doesn't work it
means that the remote shell isn't configured to split its args based
on whitespace (a very rare setting, but not unknown). If you need to
transfer a filename that contains whitespace, you'll need to either
escape the whitespace in a way that the remote shell will understand,
or use wildcards in place of the spaces. Two examples of this are:

rsync -av host:'file\ name\ with\ spaces' /dest
rsync -av host:file?name?with?spaces /dest

This latter example assumes that your shell passes through unmatched
wildcards. If it complains about "no match", put the name in quotes.

CONNECTING TO AN RSYNC SERVER
It is also possible to use rsync without a remote shell as the trans-
port. In this case you will connect to a remote rsync server running
on TCP port 873.

You may establish the connection via a web proxy by setting the envi-
ronment variable RSYNC_PROXY to a hostname:port pair pointing to your
web proxy. Note that your web proxy's configuration must support
proxy connections to port 873.

Using rsync in this way is the same as using it with a remote shell
except that:

o you use a double colon :: instead of a single colon to separate
the hostname from the path or an rsync:// URL.

o the remote server may print a message of the day when you con-
nect.

o if you specify no path name on the remote server then the list
of accessible paths on the server will be shown.

o if you specify no local destination then a listing of the spec-
ified files on the remote server is provided.

Some paths on the remote server may require authentication. If so then
you will receive a password prompt when you connect. You can avoid the
password prompt by setting the environment variable RSYNC_PASSWORD to
the password you want to use or using the --password-file option. This
may be useful when scripting rsync.

WARNING: On some systems environment variables are visible to all
users. On those systems using --password-file is recommended.

CONNECTING TO AN RSYNC SERVER OVER A REMOTE SHELL PROGRAM
It is sometimes useful to be able to set up file transfers using rsync
server capabilities on the remote machine, while still using ssh or
rsh for transport. This is especially useful when you want to connect
to a remote machine via ssh (for encryption or to get through a fire-
wall), but you still want to have access to the rsync server features
(see RUNNING AN RSYNC SERVER OVER A REMOTE SHELL PROGRAM, below).

From the user's perspective, using rsync in this way is the same as
using it to connect to an rsync server, except that you must explic-
itly set the remote shell program on the command line with --rsh=COM-
MAND. (Setting RSYNC_RSH in the environment will not turn on this
functionality.)

In order to distinguish between the remote-shell user and the rsync
server user, you can use '-l user' on your remote-shell command:

rsync -av --rsh="ssh -l ssh-user" rsync-user@host::mod-
ule[/path] local-path

The "ssh-user" will be used at the ssh level; the "rsync-user" will be
used to check against the rsyncd.conf on the remote host.

RUNNING AN RSYNC SERVER
An rsync server is configured using a configuration file. Please see
the rsyncd.conf(5) man page for more information. By default the
configuration file is called /etc/rsyncd.conf, unless rsync is running
over a remote shell program and is not running as root; in that case,
the default name is rsyncd.conf in the current directory on the remote
computer (typically $HOME).

RUNNING AN RSYNC SERVER OVER A REMOTE SHELL PROGRAM
See the rsyncd.conf(5) man page for full information on the rsync
server configuration file.

Several configuration options will not be available unless the remote
user is root (e.g. chroot, setuid/setgid, etc.). There is no need to
configure inetd or the services map to include the rsync server port
if you run an rsync server only via a remote shell program.

To run an rsync server out of a single-use ssh key, see this section
in the rsyncd.conf(5) man page.

EXAMPLES
Here are some examples of how I use rsync.

To backup my wife's home directory, which consists of large MS Word
files and mail folders, I use a cron job that runs

rsync -Cavz . arvidsjaur:backup

each night over a PPP connection to a duplicate directory on my
machine "arvidsjaur".

To synchronize my samba source trees I use the following Makefile tar-
gets:

get:
rsync -avuzb --exclude '*~' samba:samba/ .

put:
rsync -Cavuzb . samba:samba/

sync: get put

this allows me to sync with a CVS directory at the other end of the
connection. I then do cvs operations on the remote machine, which
saves a lot of time as the remote cvs protocol isn't very efficient.

I mirror a directory between my "old" and "new" ftp sites with the
command

rsync -az -e ssh --delete ~ftp/pub/samba/ nim-
bus:"~ftp/pub/tridge/samba"

this is launched from cron every few hours.

OPTIONS SUMMARY
Here is a short summary of the options available in rsync. Please
refer to the detailed description below for a complete description.

-v, --verbose increase verbosity
-q, --quiet decrease verbosity
-c, --checksum always checksum
-a, --archive archive mode, equivalent to -rlptgoD
-r, --recursive recurse into directories
-R, --relative use relative path names
--no-relative turn off --relative
--no-implied-dirs don't send implied dirs with -R
-b, --backup make backups (see --suffix & --backup-dir)
--backup-dir make backups into this directory
--suffix=SUFFIX backup suffix (default ~ w/o --backup-dir)
-u, --update update only (don't overwrite newer files)
--inplace update the destination files inplace
-K, --keep-dirlinks treat symlinked dir on receiver as dir
-l, --links copy symlinks as symlinks
-L, --copy-links copy the referent of all symlinks
--copy-unsafe-links copy the referent of "unsafe" symlinks
--safe-links ignore "unsafe" symlinks
-H, --hard-links preserve hard links
-p, --perms preserve permissions
-o, --owner preserve owner (root only)
-g, --group preserve group
-D, --devices preserve devices (root only)
-t, --times preserve times
-S, --sparse handle sparse files efficiently
-n, --dry-run show what would have been transferred
-W, --whole-file copy whole files, no incremental checks
--no-whole-file turn off --whole-file
-x, --one-file-system don't cross filesystem boundaries
-B, --block-size=SIZE force a fixed checksum block-size
-e, --rsh=COMMAND specify the remote shell
--rsync-path=PATH specify path to rsync on the remote machine
--existing only update files that already exist
--ignore-existing ignore files that already exist on receiver
--delete delete files that don't exist on sender
--delete-excluded also delete excluded files on receiver
--delete-after receiver deletes after transfer, not before
--ignore-errors delete even if there are I/O errors
--max-delete=NUM don't delete more than NUM files
--partial keep partially transferred files
--partial-dir=DIR put a partially transferred file into DIR
--force force deletion of dirs even if not empty
--numeric-ids don't map uid/gid values by user/group name
--timeout=TIME set I/O timeout in seconds
-I, --ignore-times turn off mod time & file size quick check
--size-only ignore mod time for quick check (use size)
--modify-window=NUM compare mod times with reduced accuracy
-T --temp-dir=DIR create temporary files in directory DIR
--compare-dest=DIR also compare received files relative to DIR
--link-dest=DIR create hardlinks to DIR for unchanged files
-P equivalent to --partial --progress
-z, --compress compress file data
-C, --cvs-exclude auto ignore files in the same way CVS does
--exclude=PATTERN exclude files matching PATTERN
--exclude-from=FILE exclude patterns listed in FILE
--include=PATTERN don't exclude files matching PATTERN
--include-from=FILE don't exclude patterns listed in FILE
--files-from=FILE read FILE for list of source-file names
-0 --from0 all file lists are delimited by nulls
--version print version number
--daemon run as an rsync daemon
--no-detach do not detach from the parent
--address=ADDRESS bind to the specified address
--config=FILE specify alternate rsyncd.conf file
--port=PORT specify alternate rsyncd port number
--blocking-io use blocking I/O for the remote shell
--no-blocking-io turn off --blocking-io
--stats give some file transfer stats
--progress show progress during transfer
--log-format=FORMAT log file transfers using specified format
--password-file=FILE get password from FILE
--bwlimit=KBPS limit I/O bandwidth, KBytes per second
--write-batch=FILE write a batch to FILE
--read-batch=FILE read a batch from FILE
--checksum-seed=NUM set block/file checksum seed
-4 --ipv4 prefer IPv4
-6 --ipv6 prefer IPv6
-h, --help show this help screen

OPTIONS
rsync uses the GNU long options package. Many of the command line
options have two variants, one short and one long. These are shown
below, separated by commas. Some options only have a long variant.
The '=' for options that take a parameter is optional; whitespace can
be used instead.

-h, --help
Print a short help page describing the options available in
rsync

--version
print the rsync version number and exit

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

-q, --quiet
This option decreases the amount of information you are given
during the transfer, notably suppressing information messages
from the remote server. This flag is useful when invoking rsync
from cron.

-I, --ignore-times
Normally rsync will skip any files that are already the same
size and have the same modification time-stamp. This option
turns off this "quick check" behavior.

--size-only
Normally rsync will not transfer any files that are already the
same size and have the same modification time-stamp. With the
--size-only option, files will not be transferred if they have
the same size, regardless of timestamp. This is useful when
starting to use rsync after using another mirroring system
which may not preserve timestamps exactly.

--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 transfer-
ring to Windows FAT filesystems which cannot represent times
with a 1 second resolution --modify-window=1 is useful.

-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 which
already exist and have the same checksum and size on the
receiver are not transferred. This option can be quite slow.

-a, --archive
This is equivalent to -rlptgoD. It is a quick way of saying you
want recursion and want to preserve almost everything.

Note however that -a does not preserve hardlinks, because find-
ing multiply-linked files is expensive. You must separately
specify -H.

-r, --recursive
This tells rsync to copy directories recursively. If you don't
specify this then rsync won't copy directories at all.

-R, --relative
Use relative paths. This means that the full path names speci-
fied on the command line are sent to the server rather than
just the last parts of the filenames. This is particularly use-
ful when you want to send several different directories at the
same time. For example, if you used the command

rsync foo/bar/foo.c remote:/tmp/

then this would create a file called foo.c in /tmp/ on the
remote machine. If instead you used

rsync -R foo/bar/foo.c remote:/tmp/

then a file called /tmp/foo/bar/foo.c would be created on the
remote machine -- the full path name is preserved.

--no-relative
Turn off the --relative option. This is only needed if you
want to use --files-from without its implied --relative file
processing.

--no-implied-dirs
When combined with the --relative option, the implied directo-
ries in each path are not explicitly duplicated as part of the
transfer. This makes the transfer more optimal and also allows
the two sides to have non-matching symlinks in the implied part
of the path. For instance, if you transfer the file
"/path/foo/file" with -R, the default is for rsync to ensure
that "/path" and "/path/foo" on the destination exactly match
the directories/symlinks of the source. Using the --no-
implied-dirs option would omit both of these implied dirs,
which means that if "/path" was a real directory on one machine
and a symlink of the other machine, rsync would not try to
change this.

-b, --backup
With this option, preexisting destination files are renamed as
each file is transferred or deleted. You can control where the
backup file goes and what (if any) suffix gets appended using
the --backup-dir and --suffix options.

--backup-dir=DIR
In combination with the --backup option, this tells rsync to
store all backups in the specified directory. This is very use-
ful for incremental backups. You can additionally specify a
backup suffix using the --suffix option (otherwise the files
backed up in the specified directory will keep their original
filenames). If DIR is a relative path, it is relative to the
destination directory (which changes in a recursive transfer).

--suffix=SUFFIX
This option allows you to override the default backup suffix
used with the --backup (-b) option. The default suffix is a ~
if no --backup-dir was specified, otherwise it is an empty
string.

-u, --update
This forces rsync to skip any files for which the destination
file already exists and has a date later than the source file.

In the currently implementation, a difference of file format is
always considered to be important enough for an update, no mat-
ter what date is on the objects. In other words, if the source
has a directory or a symlink where the destination has a file,
the transfer would occur regardless of the timestamps. This
might change in the future (feel free to comment on this on the
mailing list if you have an opinion).

-K, --keep-dirlinks
On the receiving side, if a symlink is pointing to a directory,
it will be treated as matching a directory from the sender.

--inplace
This causes rsync not to create a new copy of the file and then
move it into place. Instead rsync will overwrite the existing
file, meaning that the rsync algorithm can't extract the full
amount of network reduction it might otherwise (since it does
not yet try to sort data matches -- a future version may
improve this).

This option is useful for transfer of large files with block-
based changes or appended data, and also on systems that are
disk bound, not network bound.

The option implies --partial (since an interrupted transfer
does not delete the file), but conflicts with --partial-dir,
--compare-dest, and --link-dest (a future rsync version will
hopefully update the protocol to remove these restrictions).

WARNING: The file's data will be in an inconsistent state dur-
ing the transfer (and possibly afterward if the transfer gets
interrupted), so you should not use this option to update files
that are in use. Also note that rsync will be unable to update
a file inplace that is not writable by the receiving user.

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

-L, --copy-links
When symlinks are encountered, the file that they point to (the
referent) is copied, rather than the symlink. In older ver-
sions of rsync, this option also had the side-effect of telling
the receiving side to follow symlinks, such as symlinks to
directories. In a modern rsync such as this one, you'll need
to specify --keep-dirlinks (-K) to get this extra behavior.
The only exception is when sending files to an rsync that is
too old to understand -K -- in that case, the -L option will
still have the side-effect of -K on that older receiving rsync.

--copy-unsafe-links
This tells rsync to copy the referent of symbolic links that
point outside the copied tree. Absolute symlinks are also
treated like ordinary files, and so are any symlinks in the
source path itself when --relative is used.

--safe-links
This tells rsync to ignore any symbolic links which point out-
side the copied tree. All absolute symlinks are also ignored.
Using this option in conjunction with --relative may give unex-
pected results.

-H, --hard-links
This tells rsync to recreate hard links on the remote system
to be the same as the local system. Without this option hard
links are treated like regular files.

Note that rsync can only detect hard links if both parts of the
link are in the list of files being sent.

This option can be quite slow, so only use it if you need it.

-W, --whole-file
With this option the incremental rsync algorithm is not used
and the whole file is sent as-is instead. The transfer may be
faster if this option is used when the bandwidth between the
source and destination machines is higher than the bandwidth to
disk (especially when the "disk" is actually a networked
filesystem). This is the default when both the source and des-
tination are specified as local paths.

--no-whole-file
Turn off --whole-file, for use when it is the default.

-p, --perms
This option causes rsync to set the destination permissions to
be the same as the source permissions.

Without this option, each new file gets its permissions set
based on the source file's permissions and the umask at the
receiving end, while all other files (including updated files)
retain their existing permissions (which is the same behavior
as other file-copy utilities, such as cp).

-o, --owner
This option causes rsync to set the owner of the destination
file to be the same as the source file. On most systems, only
the super-user can set file ownership. By default, the preser-
vation is done by name, but may fall back to using the ID num-
ber in some circumstances. See the --numeric-ids option for a
full discussion.

-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 pro-
gram is not running as the super-user, only groups that the
receiver is a member of will be preserved. By default, the
preservation is done by name, but may fall back to using the ID
number in some circumstances. See the --numeric-ids option for
a full discussion.

-D, --devices
This option causes rsync to transfer character and block device
information to the remote system to recreate these devices.
This option is only available to the super-user.

-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 the rsync
algorithm will make the update fairly efficient if the files
haven't actually changed, you're much better off using -t).

-n, --dry-run
This tells rsync to not do any file transfers, instead it will
just report the actions it would have taken.

-S, --sparse
Try to handle sparse files efficiently so they take up less
space on the destination.

NOTE: Don't use this option when the destination is a Solaris
"tmpfs" filesystem. It doesn't seem to handle seeks over null
regions correctly and ends up corrupting the files.

-x, --one-file-system
This tells rsync not to cross filesystem boundaries when
recursing. This is useful for transferring the contents of
only one filesystem.

--existing
This tells rsync not to create any new files - only update
files that already exist on the destination.

--ignore-existing
This tells rsync not to update files that already exist on the
destination.

--max-delete=NUM
This tells rsync not to delete more than NUM files or directo-
ries. This is useful when mirroring very large trees to prevent
disasters.

--delete
This tells rsync to delete any files on the receiving side that
aren't on the sending side. Files that are excluded from
transfer are excluded from being deleted unless you use
--delete-excluded.

This option has no effect if directory recursion is not
selected.

This option can be dangerous if used incorrectly! It is a very
good idea to run first using the dry run option (-n) to see
what files would be deleted to make sure important files aren't
listed.

If the sending side detects any I/O errors then the deletion of
any files at the destination will be automatically disabled.
This is to prevent temporary filesystem failures (such as NFS
errors) on the sending side causing a massive deletion of files
on the destination. You can override this with the --ignore-
errors option.

--delete-excluded
In addition to deleting the files on the receiving side that
are not on the sending side, this tells rsync to also delete
any files on the receiving side that are excluded (see
--exclude). Implies --delete.

--delete-after
By default rsync does file deletions on the receiving side
before transferring files to try to ensure that there is suffi-
cient space on the receiving filesystem. If you want to delete
after transferring, use the --delete-after switch. Implies
--delete.

--ignore-errors
Tells --delete to go ahead and delete files even when there are
I/O errors.

--force
This options tells rsync to delete directories even if they are
not empty when they are to be replaced by non-directories.
This is only relevant without --delete because deletions are
now done depth-first. Requires the --recursive option (which
is implied by -a) to have any effect.

-B, --block-size=BLOCKSIZE
This forces the block size used in the rsync algorithm to a
fixed value. It is normally selected based on the size of each
file being updated. See the technical report for details.

-e, --rsh=COMMAND
This option allows you to choose an alternative remote shell
program to use for communication between the local and remote
copies of rsync. Typically, rsync is configured to use ssh by
default, but you may prefer to use rsh on a local network.

If this option is used with [user@]host::module/path, then the
remote shell COMMAND will be used to run an rsync server on the
remote host, and all data will be transmitted through that
remote shell connection, rather than through a direct socket
connection to a running rsync server on the remote host. See
the section "CONNECTING TO AN RSYNC SERVER OVER A REMOTE SHELL
PROGRAM" above.

Command-line arguments are permitted in COMMAND provided that
COMMAND is presented to rsync as a single argument. For exam-
ple:

-e "ssh -p 2234"

(Note that ssh users can alternately customize site-specific
connect options in their .ssh/config file.)

You can also choose the remote shell program using the
RSYNC_RSH environment variable, which accepts the same range of
values as -e.

See also the --blocking-io option which is affected by this
option.

--rsync-path=PATH
Use this to specify the path to the copy of rsync on the remote
machine. Useful when it's not in your path. Note that this is
the full path to the binary, not just the directory that the
binary is in.

-C, --cvs-exclude
This is a useful shorthand for excluding a broad range of files
that you often don't want to transfer between systems. It uses
the same algorithm that CVS uses to determine if a file should
be ignored.

The exclude list is initialized to:

RCS SCCS CVS CVS.adm RCSLOG cvslog.* tags TAGS .make.state
.nse_depinfo *~ #* .#* ,* _$* *$ *.old *.bak *.BAK *.orig *.rej
.del-* *.a *.olb *.o *.obj *.so *.exe *.Z *.elc *.ln core .svn/

then files listed in a $HOME/.cvsignore are added to the list
and any files listed in the CVSIGNORE environment variable (all
cvsignore names are delimited by whitespace).

Finally, any file is ignored if it is in the same directory as
a .cvsignore file and matches one of the patterns listed
therein. See the cvs(1) manual for more information.

--exclude=PATTERN
This option allows you to selectively exclude certain files
from the list of files to be transferred. This is most useful
in combination with a recursive transfer.

You may use as many --exclude options on the command line as
you like to build up the list of files to exclude.

See the EXCLUDE PATTERNS section for detailed information on
this option.

--exclude-from=FILE
This option is similar to the --exclude option, but instead it
adds all exclude patterns listed in the file FILE to the
exclude list. Blank lines in FILE and lines starting with ';'
or '#' are ignored. If FILE is - the list will be read from
standard input.

--include=PATTERN
This option tells rsync to not exclude the specified pattern of
filenames. This is useful as it allows you to build up quite
complex exclude/include rules.

See the EXCLUDE PATTERNS section for detailed information on
this option.

--include-from=FILE
This specifies a list of include patterns from a file. If FILE
is "-" the list will be read from standard input.

--files-from=FILE
Using this option allows you to specify the exact list of files
to transfer (as read from the specified FILE or "-" for stan-
dard input). It also tweaks the default behavior of rsync to
make transferring just the specified files and directories eas-
ier. For instance, the --relative option is enabled by default
when this option is used (use --no-relative if you want to turn
that off), all directories specified in the list are created on
the destination (rather than being noisily skipped without -r),
and the -a (--archive) option's behavior does not imply -r
(--recursive) -- specify it explicitly, if you want it.

The file names that are read from the FILE are all relative to
the source dir -- any leading slashes are removed and no ".."
references are allowed to go higher than the source dir. For
example, take this command:

rsync -a --files-from=/tmp/foo /usr remote:/backup

If /tmp/foo contains the string "bin" (or even "/bin"), the
/usr/bin directory will be created as /backup/bin on the remote
host (but the contents of the /usr/bin dir would not be sent
unless you specified -r or the names were explicitly listed in
/tmp/foo). Also keep in mind that the effect of the (enabled
by default) --relative option is to duplicate only the path
info that is read from the file -- it does not force the dupli-
cation of the source-spec path (/usr in this case).

In addition, the --files-from file can be read from the remote
host instead of the local host if you specify a "host:" in
front of the file (the host must match one end of the trans-
fer). As a short-cut, you can specify just a prefix of ":" to
mean "use the remote end of the transfer". For example:

rsync -a --files-from=:/path/file-list src:/ /tmp/copy

This would copy all the files specified in the /path/file-list
file that was located on the remote "src" host.

-0, --from0
This tells rsync that the filenames it reads from a file are
terminated by a null ('\0') character, not a NL, CR, or CR+LF.
This affects --exclude-from, --include-from, and --files-from.
It does not affect --cvs-exclude (since all names read from a
.cvsignore file are split on whitespace).

-T, --temp-dir=DIR
This option instructs rsync to use DIR as a scratch directory
when creating temporary copies of the files transferred on the
receiving side. The default behavior is to create the tempo-
rary files in the receiving directory.

--compare-dest=DIR
This option instructs rsync to use DIR on the destination
machine as an additional directory to compare destination files
against when doing transfers if the files are missing in the
destination directory. This is useful for doing transfers to a
new destination while leaving existing files intact, and then
doing a flash-cutover when all files have been successfully
transferred (for example by moving directories around and
removing the old directory, although this skips files that
haven't changed; see also --link-dest). This option increases
the usefulness of --partial because partially transferred files
will remain in the new temporary destination until they have a
chance to be completed. If DIR is a relative path, it is rela-
tive to the destination directory.

--link-dest=DIR
This option behaves like --compare-dest but also will create
hard links from DIR to the destination directory for unchanged
files. Files with changed ownership or permissions will not be
linked. An example:

rsync -av --link-dest=$PWD/prior_dir host:src_dir/ new_dir/

Like --compare-dest if DIR is a relative path, it is relative
to the destination directory. Note that rsync versions prior
to 2.6.1 had a bug that could prevent --link-dest from working
properly for a non-root user when -o was specified (or implied
by -a). If the receiving rsync is not new enough, you can work
around this bug by avoiding the -o option.

-z, --compress
With this option, rsync compresses any data from the files that
it sends to the destination machine. This option is useful on
slow connections. The compression method used is the same
method that gzip uses.

Note this this option typically achieves better compression
ratios that can be achieved by using a compressing remote
shell, or a compressing transport, as it takes advantage of the
implicit information sent for matching data blocks.

--numeric-ids
With this option rsync will transfer numeric group and user IDs
rather than using user and group names and mapping them at both
ends.

By default rsync will use the username and groupname to deter-
mine what ownership to give files. The special uid 0 and the
special group 0 are never mapped via user/group names even if
the --numeric-ids option is not specified.

If a user or group has no name on the source system or it has
no match on the destination system, then the numeric ID from
the source system is used instead. See also the comments on
the "use chroot" setting in the rsyncd.conf manpage for infor-
mation on how the chroot setting affects rsync's ability to
look up the names of the users and groups and what you can do
about it.

--timeout=TIMEOUT
This option allows you to set a maximum I/O timeout in seconds.
If no data is transferred for the specified time then rsync
will exit. The default is 0, which means no timeout.

--daemon
This tells rsync that it is to run as a daemon. The daemon may
be accessed using the host::module or rsync://host/module/ syn-
tax.

If standard input is a socket then rsync will assume that it is
being run via inetd, otherwise it will detach from the current
terminal and become a background daemon. The daemon will read
the config file (rsyncd.conf) on each connect made by a client
and respond to requests accordingly. See the rsyncd.conf(5)
man page for more details.

--no-detach
When running as a daemon, this option instructs rsync to not
detach itself and become a background process. This option is
required when running as a service on Cygwin, and may also be
useful when rsync is supervised by a program such as daemon-
tools or AIX's System Resource Controller. --no-detach is also
recommended when rsync is run under a debugger. This option
has no effect if rsync is run from inetd or sshd.

--address
By default rsync will bind to the wildcard address when run as
a daemon with the --daemon option or when connecting to a rsync
server. The --address option allows you to specify a specific
IP address (or hostname) to bind to. This makes virtual hosting
possible in conjunction with the --config option.

--config=FILE
This specifies an alternate config file than the default. This
is only relevant when --daemon is specified. The default is
/etc/rsyncd.conf unless the daemon is running over a remote
shell program and the remote user is not root; in that case the
default is rsyncd.conf in the current directory (typically
$HOME).

--port=PORT
This specifies an alternate TCP port number to use rather than
the default port 873.

--blocking-io
This tells rsync to use blocking I/O when launching a remote
shell transport. If the remote shell is either rsh or remsh,
rsync defaults to using blocking I/O, otherwise it defaults to
using non-blocking I/O. (Note that ssh prefers non-blocking
I/O.)

--no-blocking-io
Turn off --blocking-io, for use when it is the default.

--log-format=FORMAT
This allows you to specify exactly what the rsync client logs
to stdout on a per-file basis. The log format is specified
using the same format conventions as the log format option in
rsyncd.conf.

--stats
This tells rsync to print a verbose set of statistics on the
file transfer, allowing you to tell how effective the rsync
algorithm is for your data.

--partial
By default, rsync will delete any partially transferred file if
the transfer is interrupted. In some circumstances it is more
desirable to keep partially transferred files. Using the --par-
tial option tells rsync to keep the partial file which should
make a subsequent transfer of the rest of the file much faster.

--partial-dir=DIR
Turns on --partial mode, but tells rsync to put a partially
transferred file into DIR instead of writing out the file to
the destination dir. Rsync will also use a file found in this
dir as data to speed up the transfer (i.e. when you redo the
send after rsync creates a partial file) and delete such a file
after it has served its purpose. Note that if --whole-file is
specified (or implied) that an existing partial-dir file will
not be used to speedup the transfer (since rsync is sending
files without using the incremental rsync algorithm).

Rsync will create the dir if it is missing (just the last dir
-- not the whole path). This makes it easy to use a relative
path (such as "--partial-dir=.rsync-partial") to have rsync
create the partial-directory in the destination file's direc-
tory (rsync will also try to remove the DIR if a partial file
was found to exist at the start of the transfer and the DIR was
specified as a relative path).

If the partial-dir value is not an absolute path, rsync will
also add an --exclude of this value at the end of all your
existing excludes. This will prevent partial-dir files from
being transferred and also prevent the untimely deletion of
partial-dir items on the receiving side. An example: the above
--partial-dir option would add an "--exclude=.rsync-partial/"
rule at the end of any other include/exclude rules. Note that
if you are supplying your own include/exclude rules, you may
need to manually insert a rule for this directory exclusion
somewhere higher up in the list so that it has a high enough
priority to be effective (e.g., if your rules specify a trail-
ing --exclude=* rule, the auto-added rule will be ineffective).

IMPORTANT: the --partial-dir should not be writable by other
users or it is a security risk. E.g. AVOID "/tmp".

You can also set the partial-dir value the RSYNC_PARTIAL_DIR
environment variable. Setting this in the environment does not
force --partial to be enabled, but rather it effects where par-
tial files go when --partial (or -P) is used. For instance,
instead of specifying --partial-dir=.rsync-tmp along with
--progress, you could set RSYNC_PARTIAL_DIR=.rsync-tmp in your
environment and then just use the -P option to turn on the use
of the .rsync-tmp dir for partial transfers. The only time the
--partial option does not look for this environment value is
when --inplace was also specified (since --inplace conflicts
with --partial-dir).

--progress
This option tells rsync to print information showing the
progress of the transfer. This gives a bored user something to
watch. Implies --verbose without incrementing verbosity.

When the file is transferring, the data looks like this:

782448 63% 110.64kB/s 0:00:04

This tells you the current file size, the percentage of the
transfer that is complete, the current calculated file-comple-
tion rate (including both data over the wire and data being
matched locally), and the estimated time remaining in this
transfer.

After the a file is complete, it the data looks like this:

1238099 100% 146.38kB/s 0:00:08 (5, 57.1% of 396)

This tells you the final file size, that it's 100% complete,
the final transfer rate for the file, the amount of elapsed
time it took to transfer the file, and the addition of a total-
transfer summary in parentheses. These additional numbers tell
you how many files have been updated, and what percent of the
total number of files has been scanned.

-P The -P option is equivalent to --partial --progress. Its pur-
pose is to make it much easier to specify these two options for
a long transfer that may be interrupted.

--password-file
This option allows you to provide a password in a file for
accessing a remote rsync server. Note that this option is only
useful when accessing an rsync server using the built in trans-
port, not when using a remote shell as the transport. The file
must not be world readable. It should contain just the password
as a single line.

--bwlimit=KBPS
This option allows you to specify a maximum transfer rate in
kilobytes per second. This option is most effective when using
rsync with large files (several megabytes and up). Due to the
nature of rsync transfers, blocks of data are sent, then if
rsync determines the transfer was too fast, it will wait before
sending the next data block. The result is an average transfer
rate equaling the specified limit. A value of zero specifies no
limit.

--write-batch=FILE
Record a file that can later be applied to another identical
destination with --read-batch. See the "BATCH MODE" section for
details.

--read-batch=FILE
Apply all of the changes stored in FILE, a file previously gen-
erated by --write-batch. If FILE is "-" the batch data will be
read from standard input. See the "BATCH MODE" section for
details.

-4, --ipv4 or -6, --ipv6
Tells rsync to prefer IPv4/IPv6 when creating sockets. This
only affects sockets that rsync has direct control over, such
as the outgoing socket when directly contacting an rsync dae-
mon, or the incoming sockets that an rsync daemon uses to lis-
ten for connections. One of these options may be required in
older versions of Linux to work around an IPv6 bug in the ker-
nel (if you see an "address already in use" error when nothing
else is using the port, try specifying --ipv6 or --ipv4 when
starting the daemon).

--checksum-seed=NUM
Set the MD4 checksum seed to the integer NUM. This 4 byte
checksum seed is included in each block and file MD4 checksum
calculation. By default the checksum seed is generated by the
server and defaults to the current time(). This option is used
to set a specific checksum seed, which is useful for applica-
tions that want repeatable block and file checksums, or in the
case where the user wants a more random checksum seed. Note
that setting NUM to 0 causes rsync to use the default of time()
for checksum seed.

EXCLUDE PATTERNS
The exclude and include patterns specified to rsync allow for flexible
selection of which files to transfer and which files to skip.

Rsync builds an ordered list of include/exclude options as specified
on the command line. Rsync checks each file and directory name against
each exclude/include pattern in turn. The first matching pattern is
acted on. If it is an exclude pattern, then that file is skipped. If
it is an include pattern then that filename is not skipped. If no
matching include/exclude pattern is found then the filename is not
skipped.

The filenames matched against the exclude/include patterns are rela-
tive to the "root of the transfer". If you think of the transfer as a
subtree of names that are being sent from sender to receiver, the root
is where the tree starts to be duplicated in the destination direc-
tory. This root governs where patterns that start with a / match (see
below).

Because the matching is relative to the transfer-root, changing the
trailing slash on a source path or changing your use of the --relative
option affects the path you need to use in your matching (in addition
to changing how much of the file tree is duplicated on the destination
system). The following examples demonstrate this.

Let's say that we want to match two source files, one with an absolute
path of "/home/me/foo/bar", and one with a path of
"/home/you/bar/baz". Here is how the various command choices differ
for a 2-source transfer:

Example cmd: rsync -a /home/me /home/you /dest
+/- pattern: /me/foo/bar
+/- pattern: /you/bar/baz
Target file: /dest/me/foo/bar
Target file: /dest/you/bar/baz

Example cmd: rsync -a /home/me/ /home/you/ /dest
+/- pattern: /foo/bar (note missing "me")
+/- pattern: /bar/baz (note missing "you")
Target file: /dest/foo/bar
Target file: /dest/bar/baz

Example cmd: rsync -a --relative /home/me/ /home/you /dest
+/- pattern: /home/me/foo/bar (note full path)
+/- pattern: /home/you/bar/baz (ditto)
Target file: /dest/home/me/foo/bar
Target file: /dest/home/you/bar/baz

Example cmd: cd /home; rsync -a --relative me/foo you/ /dest
+/- pattern: /me/foo/bar (starts at specified path)
+/- pattern: /you/bar/baz (ditto)
Target file: /dest/me/foo/bar
Target file: /dest/you/bar/baz

The easiest way to see what name you should include/exclude is to just
look at the output when using --verbose and put a / in front of the
name (use the --dry-run option if you're not yet ready to copy any
files).

Note that, when using the --recursive (-r) option (which is implied by
-a), every subcomponent of every path is visited from the top down, so
include/exclude patterns get applied recursively to each subcomponent.
The exclude patterns actually short-circuit the directory traversal
stage when rsync finds the files to send. If a pattern excludes a
particular parent directory, it can render a deeper include pattern
ineffectual because rsync did not descend through that excluded sec-
tion of the hierarchy.

Note also that the --include and --exclude options take one pattern
each. To add multiple patterns use the --include-from and --exclude-
from options or multiple --include and --exclude options.

The patterns can take several forms. The rules are:

o if the pattern starts with a / then it is matched against the
start of the filename, otherwise it is matched against the end
of the filename. This is the equivalent of a leading ^ in
regular expressions. Thus "/foo" would match a file called
"foo" at the transfer-root (see above for how this is different
from the filesystem-root). On the other hand, "foo" would
match any file called "foo" anywhere in the tree because the
algorithm is applied recursively from top down; it behaves as
if each path component gets a turn at being the end of the file
name.

o if the pattern ends with a / then it will only match a direc-
tory, not a file, link, or device.

o if the pattern contains a wildcard character from the set *?[
then expression matching is applied using the shell filename
matching rules. Otherwise a simple string match is used.

o the double asterisk pattern "**" will match slashes while a
single asterisk pattern "*" will stop at slashes.

o if the pattern contains a / (not counting a trailing /) or a
"**" then it is matched against the full filename, including
any leading directory. If the pattern doesn't contain a / or a
"**", then it is matched only against the final component of
the filename. Again, remember that the algorithm is applied
recursively so "full filename" can actually be any portion of a
path below the starting directory.

o if the pattern starts with "+ " (a plus followed by a space)
then it is always considered an include pattern, even if speci-
fied as part of an exclude option. The prefix is discarded
before matching.

o if the pattern starts with "- " (a minus followed by a space)
then it is always considered an exclude pattern, even if speci-
fied as part of an include option. The prefix is discarded
before matching.

o if the pattern is a single exclamation mark ! then the current
include/exclude list is reset, removing all previously defined
patterns.

The +/- rules are most useful in a list that was read from a file,
allowing you to have a single exclude list that contains both include
and exclude options in the proper order.

Remember that the matching occurs at every step in the traversal of
the directory hierarchy, so you must be sure that all the parent
directories of the files you want to include are not excluded. This
is particularly important when using a trailing '*' rule. For
instance, this won't work:

+ /some/path/this-file-will-not-be-found
+ /file-is-included
- *

This fails because the parent directory "some" is excluded by the '*'
rule, so rsync never visits any of the files in the "some" or
"some/path" directories. One solution is to ask for all directories
in the hierarchy to be included by using a single rule: --include='*/'
(put it somewhere before the --exclude='*' rule). Another solution is
to add specific include rules for all the parent dirs that need to be
visited. For instance, this set of rules works fine:

+ /some/
+ /some/path/
+ /some/path/this-file-is-found
+ /file-also-included
- *

Here are some examples of exclude/include matching:

o --exclude "*.o" would exclude all filenames matching *.o

o --exclude "/foo" would exclude a file called foo in the trans-
fer-root directory

o --exclude "foo/" would exclude any directory called foo

o --exclude "/foo/*/bar" would exclude any file called bar two
levels below a directory called foo in the transfer-root direc-
tory

o --exclude "/foo/**/bar" would exclude any file called bar two
or more levels below a directory called foo in the transfer-
root directory

o --include "*/" --include "*.c" --exclude "*" would include all
directories and C source files

o --include "foo/" --include "foo/bar.c" --exclude "*" would
include only foo/bar.c (the foo/ directory must be explicitly
included or it would be excluded by the "*")

BATCH MODE
Note: Batch mode should be considered experimental in this version of
rsync. The interface and behavior have now stabilized, though, so feel
free to try this out.

Batch mode can be used to apply the same set of updates to many iden-
tical systems. Suppose one has a tree which is replicated on a number
of hosts. Now suppose some changes have been made to this source tree
and those changes need to be propagated to the other hosts. In order
to do this using batch mode, rsync is run with the write-batch option
to apply the changes made to the source tree to one of the destination
trees. The write-batch option causes the rsync client to store in a
"batch file" all the information needed to repeat this operation
against other, identical destination trees.

To apply the recorded changes to another destination tree, run rsync
with the read-batch option, specifying the name of the same batch
file, and the destination tree. Rsync updates the destination tree
using the information stored in the batch file.

For convenience, one additional file is creating when the write-batch
option is used. This file's name is created by appending ".sh" to the
batch filename. The .sh file contains a command-line suitable for
updating a destination tree using that batch file. It can be executed
using a Bourne(-like) shell, optionally passing in an alternate desti-
nation tree pathname which is then used instead of the original path.
This is useful when the destination tree path differs from the origi-
nal destination tree path.

Generating the batch file once saves having to perform the file sta-
tus, checksum, and data block generation more than once when updating
multiple destination trees. Multicast transport protocols can be used
to transfer the batch update files in parallel to many hosts at once,
instead of sending the same data to every host individually.

Examples:

$ rsync --write-batch=foo -a host:/source/dir/ /adest/dir/
$ scp foo* remote:
$ ssh remote ./foo.sh /bdest/dir/

$ rsync --write-batch=foo -a /source/dir/ /adest/dir/
$ ssh remote rsync --read-batch=- -a /bdest/dir/ host "remote" is then updated with the
batched data going into the directory /bdest/dir. The differences
between the two examples reveals some of the flexibility you have in
how you deal with batches:

o The first example shows that the initial copy doesn't have to
be local -- you can push or pull data to/from a remote host
using either the remote-shell syntax or rsync daemon syntax, as
desired.

o The first example uses the created "foo.sh" file to get the
right rsync options when running the read-batch command on the
remote host.

o The second example reads the batch data via standard input so
that the batch file doesn't need to be copied to the remote
machine first. This example avoids the foo.sh script because
it needed to use a modified --read-batch option, but you could
edit the script file if you wished to make use of it (just be
sure that no other option is trying to use standard input, such
as the "--exclude-from=-" option).

Caveats:

The read-batch option expects the destination tree that it is updating
to be identical to the destination tree that was used to create the
batch update fileset. When a difference between the destination trees
is encountered the update might be discarded with no error (if the
file appears to be up-to-date already) or the file-update may be
attempted and then, if the file fails to verify, the update discarded
with an error. This means that it should be safe to re-run a read-
batch operation if the command got interrupted. If you wish to force
the batched-update to always be attempted regardless of the file's
size and date, use the -I option (when reading the batch). If an
error occurs, the destination tree will probably be in a partially
updated state. In that case, rsync can be used in its regular (non-
batch) mode of operation to fix up the destination tree.

The rsync version used on all destinations must be at least as new as
the one used to generate the batch file. Rsync will die with an error
if the protocol version in the batch file is too new for the batch-
reading rsync to handle.

The --dry-run (-n) option does not work in batch mode and yields a
runtime error.

When reading a batch file, rsync will force the value of certain
options to match the data in the batch file if you didn't set them to
the same as the batch-writing command. Other options can (and should)
be changed. For instance --write-batch changes to --read-batch,
--files-from is dropped, and the --include/--exclude options are not
needed unless --delete is specified without --delete-excluded.

The code that creates the BATCH.sh file transforms any include/exclude
options into a single list that is appended as a "here" document to
the shell script file. An advanced user can use this to modify the
exclude list if a change in what gets deleted by --delete is desired.
A normal user can ignore this detail and just use the shell script as
an easy way to run the appropriate --read-batch command for the
batched data.

The original batch mode in rsync was based on "rsync+", but the latest
version uses a new implementation.

SYMBOLIC LINKS
Three basic behaviors are possible when rsync encounters a symbolic
link in the source directory.

By default, symbolic links are not transferred at all. A message
"skipping non-regular" file is emitted for any symlinks that exist.

If --links is specified, then symlinks are recreated with the same
target on the destination. Note that --archive implies --links.

If --copy-links is specified, then symlinks are "collapsed" by copying
their referent, rather than the symlink.

rsync also distinguishes "safe" and "unsafe" symbolic links. An exam-
ple where this might be used is a web site mirror that wishes ensure
the rsync module they copy does not include symbolic links to
/etc/passwd in the public section of the site. Using --copy-unsafe-
links will cause any links to be copied as the file they point to on
the destination. Using --safe-links will cause unsafe links to be
omitted altogether.

Symbolic links are considered unsafe if they are absolute symlinks
(start with /), empty, or if they contain enough ".." components to
ascend from the directory being copied.

DIAGNOSTICS
rsync occasionally produces error messages that may seem a little
cryptic. The one that seems to cause the most confusion is "protocol
version mismatch - is your shell clean?".

This message is usually caused by your startup scripts or remote shell
facility producing unwanted garbage on the stream that rsync is using
for its transport. The way to diagnose this problem is to run your
remote shell like this:

ssh remotehost /bin/true > out.dat

then look at out.dat. If everything is working correctly then out.dat
should be a zero length file. If you are getting the above error from
rsync then you will probably find that out.dat contains some text or
data. Look at the contents and try to work out what is producing it.
The most common cause is incorrectly configured shell startup scripts
(such as .cshrc or .profile) that contain output statements for non-
interactive logins.

If you are having trouble debugging include and exclude patterns, then
try specifying the -vv option. At this level of verbosity rsync will
show why each individual file is included or excluded.

EXIT VALUES
0 Success

1 Syntax or usage error

2 Protocol incompatibility

3 Errors selecting input/output files, dirs

4 Requested action not supported: an attempt was made to manipu-
late 64-bit files on a platform that cannot support them; or an
option was specified that is supported by the client and not by
the server.

5 Error starting client-server protocol

10 Error in socket I/O

11 Error in file I/O

12 Error in rsync protocol data stream

13 Errors with program diagnostics

14 Error in IPC code

20 Received SIGUSR1 or SIGINT

21 Some error returned by waitpid()

22 Error allocating core memory buffers

23 Partial transfer due to error

24 Partial transfer due to vanished source files

30 Timeout in data send/receive

ENVIRONMENT VARIABLES
CVSIGNORE
The CVSIGNORE environment variable supplements any ignore pat-
terns in .cvsignore files. See the --cvs-exclude option for
more details.

RSYNC_RSH
The RSYNC_RSH environment variable allows you to override the
default shell used as the transport for rsync. Command line
options are permitted after the command name, just as in the -e
option.

RSYNC_PROXY
The RSYNC_PROXY environment variable allows you to redirect
your rsync client to use a web proxy when connecting to a rsync
daemon. You should set RSYNC_PROXY to a hostname:port pair.

RSYNC_PASSWORD
Setting RSYNC_PASSWORD to the required password allows you to
run authenticated rsync connections to an rsync daemon without
user intervention. Note that this does not supply a password to
a shell transport such as ssh.

USER or LOGNAME
The USER or LOGNAME environment variables are used to determine
the default username sent to an rsync server. If neither is
set, the username defaults to "nobody".

HOME The HOME environment variable is used to find the user's
default .cvsignore file.

FILES
/etc/rsyncd.conf or rsyncd.conf