Tweaked a comment.

[rsync/rsync.git] / rsync.yo

mailto(rsync-bugs@samba.org)
manpage(rsync)(1)(8 Feb 2006)()()
manpagename(rsync)(faster, flexible replacement for rcp)
manpagesynopsis()

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

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

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

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

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

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

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

manpagedescription()

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 technical
report that accompanies this package.

Some of the additional features of rsync are:

itemize(
  it() support for copying links, devices, owners, groups, and permissions
  it() exclude and exclude-from options similar to GNU tar
  it() a CVS exclude mode for ignoring the same files that CVS would ignore
  it() can use any transparent remote shell, including ssh or rsh
  it() does not require super-user privileges
  it() pipelining of file transfers to minimize latency costs
  it() support for anonymous or authenticated rsync daemons (ideal for
       mirroring)
)

manpagesection(GENERAL)

Rsync copies files either to or from a remote host, or locally on the
current host (it does not support copying files between two remote hosts).

There are two different ways for rsync to contact a remote system: using a
remote-shell program as the transport (such as ssh or rsh) or contacting 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 directly 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 remote source is specified without a destination,
the remote 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 bf(--list-only) option).

manpagesection(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 bf(-e)
command line option, or by setting the RSYNC_RSH environment variable.

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

manpagesection(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:

quote(tt(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. See the tech report for details.

quote(tt(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.

quote(tt(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 attributes 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:

quote(
tt(rsync -av /src/foo /dest)nl()
tt(rsync -av /src/foo/ /dest/foo)nl()
)

Note also that host and module references don't require a trailing slash to
copy the contents of the default directory.  For example, both of these
copy the remote directory's contents into "/dest":

quote(
tt(rsync -av host: /dest)nl()
tt(rsync -av host::module /dest)nl()
)

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.

Finally, you can list all the (listable) modules available from a
particular rsync daemon by leaving off the module name:

quote(tt(rsync somehost.mydomain.com::))

See the following section for more details.

manpagesection(ADVANCED USAGE)

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

quote(tt(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.

quote(tt(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:

quote(
tt(rsync -av host:'file\ name\ with\ spaces' /dest)nl()
tt(rsync -av host:file?name?with?spaces /dest)nl()
)

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

manpagesection(CONNECTING TO AN RSYNC DAEMON)

It is also possible to use rsync without a remote shell as the transport.
In this case you will directly connect to a remote rsync daemon, typically
using TCP port 873.  (This obviously requires the daemon to be running on
the remote system, so refer to the STARTING AN RSYNC DAEMON TO ACCEPT
CONNECTIONS section below for information on that.)

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

itemize(
        it() you either use a double colon :: instead of a single colon to
        separate the hostname from the path, or you use an rsync:// URL.
        it() the first word of the "path" is actually a module name.
        it() the remote daemon may print a message of the day when you
        connect.
        it() if you specify no path name on the remote daemon then the
        list of accessible paths on the daemon will be shown.
        it() if you specify no local destination then a listing of the
        specified files on the remote daemon is provided.
        it() you must not specify the bf(--rsh) (bf(-e)) option.
)

An example that copies all the files in a remote module named "src":

verb(    rsync -av host::src /dest)

Some modules on the remote daemon may require authentication. If so,
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 bf(--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 bf(--password-file) is recommended.

You may establish the connection via a web proxy by setting the
environment 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.

manpagesection(USING RSYNC-DAEMON FEATURES VIA A REMOTE-SHELL CONNECTION)

It is sometimes useful to use various features of an rsync daemon (such as
named modules) without actually allowing any new socket connections into a
system (other than what is already required to allow remote-shell access).
Rsync supports connecting to a host using a remote shell and then spawning
a single-use "daemon" server that expects to read its config file in the
home dir of the remote user.  This can be useful if you want to encrypt a
daemon-style transfer's data, but since the daemon is started up fresh by
the remote user, you may not be able to use features such as chroot or
change the uid used by the daemon.  (For another way to encrypt a daemon
transfer, consider using ssh to tunnel a local port to a remote machine and
configure a normal rsync daemon on that remote host to only allow
connections from "localhost".)

From the user's perspective, a daemon transfer via a remote-shell
connection uses nearly the same command-line syntax as a normal
rsync-daemon transfer, with the only exception being that you must
explicitly set the remote shell program on the command-line with the
bf(--rsh=COMMAND) option.  (Setting the RSYNC_RSH in the environment
will not turn on this functionality.)  For example:

verb(    rsync -av --rsh=ssh host::module /dest)

If you need to specify a different remote-shell user, keep in mind that the
user@ prefix in front of the host is specifying the rsync-user value (for a
module that requires user-based authentication).  This means that you must
give the '-l user' option to ssh when specifying the remote-shell:

verb(    rsync -av -e "ssh -l ssh-user" rsync-user@host::module /dest)

The "ssh-user" will be used at the ssh level; the "rsync-user" will be
used to log-in to the "module".

manpagesection(STARTING AN RSYNC DAEMON TO ACCEPT CONNECTIONS)

In order to connect to an rsync daemon, the remote system needs to have a
daemon already running (or it needs to have configured something like inetd
to spawn an rsync daemon for incoming connections on a particular port).
For full information on how to start a daemon that will handling incoming
socket connections, see the rsyncd.conf(5) man page -- that is the config
file for the daemon, and it contains the full details for how to run the
daemon (including stand-alone and inetd configurations).

If you're using one of the remote-shell transports for the transfer, there is
no need to manually start an rsync daemon.

manpagesection(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

quote(tt(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
targets:

verb(    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:

tt(rsync -az -e ssh --delete ~ftp/pub/samba nimbus:"~ftp/pub/tridge")

This is launched from cron every few hours.

manpagesection(OPTIONS SUMMARY)

Here is a short summary of the options available in rsync. Please refer
to the detailed description below for a complete description.  verb(
 -v, --verbose               increase verbosity
 -q, --quiet                 suppress non-error messages
 -c, --checksum              skip based on checksum, not mod-time & size
 -a, --archive               archive mode; same as -rlptgoD (no -H)
     --no-OPTION             turn off an implied OPTION (e.g. --no-D)
 -r, --recursive             recurse into directories
 -R, --relative              use relative path names
     --no-implied-dirs       don't send implied dirs with --relative
 -b, --backup                make backups (see --suffix & --backup-dir)
     --backup-dir=DIR        make backups into hierarchy based in DIR
     --suffix=SUFFIX         backup suffix (default ~ w/o --backup-dir)
 -u, --update                skip files that are newer on the receiver
     --inplace               update destination files in-place
     --append                append data onto shorter files
 -d, --dirs                  transfer directories without recursing
 -l, --links                 copy symlinks as symlinks
 -L, --copy-links            transform symlink into referent file/dir
     --copy-unsafe-links     only "unsafe" symlinks are transformed
     --safe-links            ignore symlinks that point outside the tree
 -H, --hard-links            preserve hard links
 -K, --keep-dirlinks         treat symlinked dir on receiver as dir
 -p, --perms                 preserve permissions
 -E, --executability         preserve executability
     --chmod=CHMOD           change destination permissions
 -o, --owner                 preserve owner (super-user only)
 -g, --group                 preserve group
     --devices               preserve device files (super-user only)
     --specials              preserve special files
 -D                          same as --devices --specials
 -t, --times                 preserve times
 -O, --omit-dir-times        omit directories when preserving times
     --super                 receiver attempts super-user activities
 -S, --sparse                handle sparse files efficiently
 -n, --dry-run               show what would have been transferred
 -W, --whole-file            copy files whole (without rsync algorithm)
 -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 to use
     --rsync-path=PROGRAM    specify the rsync to run on remote machine
     --existing              ignore non-existing files on receiving side
     --ignore-existing       ignore files that already exist on receiver
     --remove-sent-files     sent files/symlinks are removed from sender
     --del                   an alias for --delete-during
     --delete                delete files that don't exist on sender
     --delete-before         receiver deletes before transfer (default)
     --delete-during         receiver deletes during xfer, not before
     --delete-after          receiver deletes after transfer, not before
     --delete-excluded       also delete excluded files on receiver
     --ignore-errors         delete even if there are I/O errors
     --force                 force deletion of dirs even if not empty
     --max-delete=NUM        don't delete more than NUM files
     --max-size=SIZE         don't transfer any file larger than SIZE
     --min-size=SIZE         don't transfer any file smaller than SIZE
     --partial               keep partially transferred files
     --partial-dir=DIR       put a partially transferred file into DIR
     --delay-updates         put all updated files into place at end
 -m, --prune-empty-dirs      prune empty directory chains from file-list
     --numeric-ids           don't map uid/gid values by user/group name
     --timeout=TIME          set I/O timeout in seconds
 -I, --ignore-times          don't skip files that match size and time
     --size-only             skip files that match in size
     --modify-window=NUM     compare mod-times with reduced accuracy
 -T, --temp-dir=DIR          create temporary files in directory DIR
 -y, --fuzzy                 find similar file for basis if no dest file
     --compare-dest=DIR      also compare received files relative to DIR
     --copy-dest=DIR         ... and include copies of unchanged files
     --link-dest=DIR         hardlink to files in DIR when unchanged
 -z, --compress              compress file data during the transfer
     --compress-level=NUM    explicitly set compression level
 -C, --cvs-exclude           auto-ignore files in the same way CVS does
 -f, --filter=RULE           add a file-filtering RULE
 -F                          same as --filter='dir-merge /.rsync-filter'
                             repeated: --filter='- .rsync-filter'
     --exclude=PATTERN       exclude files matching PATTERN
     --exclude-from=FILE     read exclude patterns from FILE
     --include=PATTERN       don't exclude files matching PATTERN
     --include-from=FILE     read include patterns from FILE
     --files-from=FILE       read list of source-file names from FILE
 -0, --from0                 all *from/filter files are delimited by 0s
     --address=ADDRESS       bind address for outgoing socket to daemon
     --port=PORT             specify double-colon alternate port number
     --sockopts=OPTIONS      specify custom TCP options
     --blocking-io           use blocking I/O for the remote shell
     --stats                 give some file-transfer stats
 -8, --8-bit-output          leave high-bit chars unescaped in output
 -h, --human-readable        output numbers in a human-readable format
     --progress              show progress during transfer
 -P                          same as --partial --progress
 -i, --itemize-changes       output a change-summary for all updates
     --log-format=FORMAT     output filenames using the specified format
     --password-file=FILE    read password from FILE
     --list-only             list the files instead of copying them
     --bwlimit=KBPS          limit I/O bandwidth; KBytes per second
     --write-batch=FILE      write a batched update to FILE
     --only-write-batch=FILE like --write-batch but w/o updating dest
     --read-batch=FILE       read a batched update from FILE
     --protocol=NUM          force an older protocol version to be used
     --checksum-seed=NUM     set block/file checksum seed (advanced)
 -4, --ipv4                  prefer IPv4
 -6, --ipv6                  prefer IPv6
     --version               print version number
(-h) --help                  show this help (see below for -h comment)
)

Rsync can also be run as a daemon, in which case the following options are
accepted: verb(
     --daemon                run as an rsync daemon
     --address=ADDRESS       bind to the specified address
     --bwlimit=KBPS          limit I/O bandwidth; KBytes per second
     --config=FILE           specify alternate rsyncd.conf file
     --no-detach             do not detach from the parent
     --port=PORT             listen on alternate port number
     --sockopts=OPTIONS      specify custom TCP options
 -v, --verbose               increase verbosity
 -4, --ipv4                  prefer IPv4
 -6, --ipv6                  prefer IPv6
 -h, --help                  show this help (if used after --daemon)
)

manpageoptions()

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.

startdit()
dit(bf(--help)) Print a short help page describing the options
available in rsync and exit.  For backward-compatibility with older
versions of rsync, the help will also be output if you use the bf(-h)
option without any other args.

dit(bf(--version)) print the rsync version number and exit.

dit(bf(-v, --verbose)) This option increases the amount of information you
are given during the transfer.  By default, rsync works silently. A
single bf(-v) will give you information about what files are being
transferred and a brief summary at the end. Two bf(-v) flags will give you
information on what files are being skipped and slightly more
information at the end. More than two bf(-v) flags 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 bf(--log-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 bf(-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
bf(--itemize-changes) or adding "%i" to the bf(--log-format) setting), the
output (on the client) increases to mention all items that are changed in
any way.  See the bf(--log-format) option for more details.

dit(bf(-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.

dit(bf(-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.

dit(bf(--size-only)) Normally rsync will not transfer any files that are
already the same size and have the same modification time-stamp. With the
bf(--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.

dit(bf(--modify-window)) When comparing two timestamps, rsync treats the
timestamps as being equal if they differ by no more than the modify-window
value.  This is normally 0 (for an exact match), but you may find it useful
to set this to a larger value in some situations.  In particular, when
transferring to or from an MS Windows FAT filesystem (which represents
times with a 2-second resolution), bf(--modify-window=1) is useful
(allowing times to differ by up to 1 second).

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

dit(bf(-a, --archive)) This is equivalent to bf(-rlptgoD). It is a quick
way of saying you want recursion and want to preserve almost
everything (with -H being a notable omission).
The only exception to the above equivalence is when bf(--files-from) is
specified, in which case bf(-r) is not implied.

Note that bf(-a) bf(does not preserve hardlinks), because
finding multiply-linked files is expensive.  You must separately
specify bf(-H).

dit(--no-OPTION) You may turn off one or more implied options by prefixing
the option name with "no-".  Not all options may be prefixed with a "no-":
only options that are implied by other options (e.g. bf(--no-D),
bf(--no-perms)) or have different defaults in various circumstances
(e.g. bf(--no-whole-file), bf(--no-blocking-io), bf(--no-dirs)).  You may
specify either the short or the long option name after the "no-" prefix
(e.g. bf(--no-R) is the same as bf(--no-relative)).

For example: if you want to use bf(-a) (bf(--archive)) but don't want
bf(-o) (bf(--owner)), instead of converting bf(-a) into bf(-rlptgD), you
could specify bf(-a --no-o) (or bf(-a --no-owner)).

The order of the options is important:  if you specify bf(--no-r -a), the
bf(-r) option would end up being turned on, the opposite of bf(-a --no-r).
Note also that the side-effects of the bf(--files-from) option are NOT
positional, as it affects the default state of several options and slightly
changes the meaning of bf(-a) (see the bf(--files-from) option for more
details).

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

dit(bf(-R, --relative)) Use relative paths. This means that the full path
names specified on the command line are sent to the server rather than
just the last parts of the filenames. This is particularly useful when
you want to send several different directories at the same time. For
example, if you used this command:

quote(tt(   rsync -av /foo/bar/baz.c remote:/tmp/))

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

quote(tt(   rsync -avR /foo/bar/baz.c remote:/tmp/))

then a file called /tmp/foo/bar/baz.c would be created on the remote
machine -- the full path name is preserved.  To limit the amount of
path information that is sent, you have a couple options:  (1) With
a modern rsync on the sending side (beginning with 2.6.7), you can
insert a dot dir into the source path, like this:

quote(tt(   rsync -avR /foo/./bar/baz.c remote:/tmp/))

That would create /tmp/bar/baz.c on the remote machine.  (Note that the
dot dir must followed by a slash, so "/foo/." would not be abbreviated.)
(2) For older rsync versions, you would need to use a chdir to limit the
source path.  For example, when pushing files:

quote(tt(   (cd /foo; rsync -avR bar/baz.c remote:/tmp/) ))

(Note that the parens put the two commands into a sub-shell, so that the
"cd" command doesn't remain in effect for future commands.)
If you're pulling files, use this idiom (which doesn't work with an
rsync daemon):

quote(
tt(   rsync -avR --rsync-path="cd /foo; rsync" \ )nl()
tt(       remote:bar/baz.c /tmp/)
)

dit(bf(--no-implied-dirs)) When combined with the bf(--relative) option, the
implied directories 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 bf(-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 bf(--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.

dit(bf(-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
bf(--backup-dir) and bf(--suffix) options.

Note that if you don't specify bf(--backup-dir), (1) the
bf(--omit-dir-times) option will be implied, and (2) if bf(--delete) is
also in effect (without bf(--delete-excluded)), rsync will add a "protect"
filter-rule for the backup suffix to the end of all your existing excludes
(e.g. -f "P *~").  This will prevent previously backed-up files from being
deleted.  Note that if you are supplying your own filter rules, you may
need to manually insert your own exclude/protect rule somewhere higher up
in the list so that it has a high enough priority to be effective (e.g., if
your rules specify a trailing inclusion/exclusion of '*', the auto-added
rule would never be reached).

dit(bf(--backup-dir=DIR)) In combination with the bf(--backup) option, this
tells rsync to store all backups in the specified directory. This is
very useful for incremental backups.  You can additionally
specify a backup suffix using the bf(--suffix) option
(otherwise the files backed up in the specified directory
will keep their original filenames).

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

dit(bf(-u, --update)) This forces rsync to skip any files which exist on
the destination and have a modified time that is newer than the source
file.  (If an existing destination file has a modify time equal to the
source file's, it will be updated if the sizes are different.)

In the current implementation of bf(--update), a difference of file format
between the sender and receiver is always
considered to be important enough for an update, no matter 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).

dit(bf(--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 accomplish the full amount of
network reduction it might be able to otherwise (since it does not yet try
to sort data matches).  One exception to this is if you combine the option
with bf(--backup), since rsync is smart enough to use the backup file as the
basis file for the transfer.

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 bf(--partial) (since an interrupted transfer does not delete
the file), but conflicts with bf(--partial-dir) and bf(--delay-updates).
Prior to rsync 2.6.4 bf(--inplace) was also incompatible with bf(--compare-dest)
and bf(--link-dest).

WARNING: The file's data will be in an inconsistent state during 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 in-place that is not writable by the
receiving user.

dit(bf(--append)) This causes rsync to update a file by appending data onto
the end of the file, which presumes that the data that already exists on
the receiving side is identical with the start of the file on the sending
side.  If that is not true, the file will fail the checksum test, and the
resend will do a normal bf(--inplace) update to correct the mismatched data.
Only files on the receiving side that are shorter than the corresponding
file on the sending side (as well as new files) are sent.
Implies bf(--inplace), but does not conflict with bf(--sparse) (though the
bf(--sparse) option will be auto-disabled if a resend of the already-existing
data is required).

dit(bf(-d, --dirs)) Tell the sending side to include any directories that
are encountered.  Unlike bf(--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
bf(--recursive) option, rsync will skip all directories it encounters (and
output a message to that effect for each one).  If you specify both
bf(--dirs) and bf(--recursive), bf(--recursive) takes precedence.

dit(bf(-l, --links)) When symlinks are encountered, recreate the
symlink on the destination.

dit(bf(-L, --copy-links)) When symlinks are encountered, the file that
they point to (the referent) is copied, rather than the symlink.  In older
versions 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 bf(--keep-dirlinks) (bf(-K))
to get this extra behavior.  The only exception is when sending files to
an rsync that is too old to understand bf(-K) -- in that case, the bf(-L) option
will still have the side-effect of bf(-K) on that older receiving rsync.

dit(bf(--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 bf(--relative) is used.

dit(bf(--safe-links)) This tells rsync to ignore any symbolic links
which point outside the copied tree. All absolute symlinks are
also ignored. Using this option in conjunction with bf(--relative) may
give unexpected results.

dit(bf(-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.

dit(bf(-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.

dit(bf(-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 destination are specified as local paths.

dit(bf(-p, --perms)) This option causes the receiving rsync to set the
destination permissions to be the same as the source permissions.  (See
also the bf(--chmod) option for a way to modify what rsync considers to
be the source permissions.)

When this option is em(off), permissions are set as follows:

quote(itemize(
  it() Existing files (including updated files) retain their existing
  permissions, though the bf(--executability) option might change just
  the execute permission for the file.
  it() New files get their "normal" permission bits set to the source
  file's permissions masked with the receiving end's umask setting, and
  their special permission bits disabled except in the case where a new
  directory inherits a setgid bit from its parent directory.
))

Thus, when bf(--perms) and bf(--executability) are both disabled,
rsync's behavior is the same as that of other file-copy utilities,
such as bf(cp)(1) and bf(tar)(1).

In summary: to give destination files (both old and new) the source
permissions, use bf(--perms).  To give new files the destination-default
permissions (while leaving existing files unchanged), make sure that the
bf(--perms) option is off and use bf(--chmod=ugo=rwX) (which ensures that
all non-masked bits get enabled).  If you'd care to make this latter
behavior easier to type, you could define a popt alias for it, such as
putting this line in the file ~/.popt (this defines the bf(-s) option,
and includes --no-g to use the default group of the destination dir):

quote(tt(   rsync alias -s --no-p --no-g --chmod=ugo=rwX))

You could then use this new option in a command such as this one:

quote(tt(   rsync -asv src/ dest/))

(Caveat: make sure that bf(-a) does not follow bf(-s), or it will re-enable
the "--no-*" options.)

The preservation of the destination's setgid bit on newly-created
directories when bf(--perms) is off was added in rsync 2.6.7.  Older rsync
versions erroneously preserved the three special permission bits for
newly-created files when bf(--perms) was off, while overriding the
destination's setgid bit setting on a newly-created directory.  (Keep in
mind that it is the version of the receiving rsync that affects this
behavior.)

dit(bf(-E, --executability)) This option causes rsync to preserve the
executability (or non-executability) of regular files when bf(--perms) is
not enabled.  A regular file is considered to be executable if at least one
'x' is turned on in its permissions.  When an existing destination file's
executability differs from that of the corresponding source file, rsync
modifies the destination file's permissions as follows:

quote(itemize(
  it() To make a file non-executable, rsync turns off all its 'x'
  permissions.
  it() To make a file executable, rsync turns on each 'x' permission that
  has a corresponding 'r' permission enabled.
))

If bf(--perms) is enabled, this option is ignored.

dit(bf(--chmod)) This option tells rsync to apply one or more
comma-separated "chmod" strings to the permission of the files in the
transfer.  The resulting value is treated as though it was the permissions
that the sending side supplied for the file, which means that this option
can seem to have no effect on existing files if bf(--perms) is not enabled.

In addition to the normal parsing rules specified in the bf(chmod)(1)
manpage, you can specify an item that should only apply to a directory by
prefixing it with a 'D', or specify an item that should only apply to a
file by prefixing it with a 'F'.  For example:

quote(--chmod=Dg+s,ug+w,Fo-w,+X)

It is also legal to specify multiple bf(--chmod) options, as each
additional option is just appended to the list of changes to make.

See the bf(--perms) and bf(--executability) options for how the resulting
permission value can be applied to the files in the transfer.

dit(bf(-o, --owner)) This option causes rsync to set the owner of the
destination file to be the same as the source file.  By default, the
preservation is done by name, but may fall back to using the ID number
in some circumstances (see the bf(--numeric-ids) option for a full
discussion).
This option has no effect if the receiving rsync is not run as the
super-user and bf(--super) is not specified.

dit(bf(-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 with the bf(--no-super)
option), 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 bf(--numeric-ids) option for a full discussion.

dit(bf(--devices)) This option causes rsync to transfer character and
block device files to the remote system to recreate these devices.
This option has no effect if the receiving rsync is not run as the
super-user and bf(--super) is not specified.

dit(bf(--specials)) This option causes rsync to transfer special files
such as named sockets and fifos.

dit(bf(-D)) The bf(-D) option is equivalent to bf(--devices) bf(--specials).

dit(bf(-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 bf(-t) or bf(-a) will
cause the next transfer to behave as if it used bf(-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 bf(-t)).

dit(bf(-O, --omit-dir-times)) This tells rsync to omit directories when
it is preserving modification times (see bf(--times)).  If NFS is sharing
the directories on the receiving side, it is a good idea to use bf(-O).
This option is inferred if you use bf(--backup) without bf(--backup-dir).

dit(bf(--super)) This tells the receiving side to attempt super-user
activities even if the receiving rsync wasn't run by the super-user.  These
activities include: preserving users via the bf(--owner) option, preserving
all groups (not just the current user's groups) via the bf(--groups)
option, and copying devices via the bf(--devices) option.  This is useful
for systems that allow such activities without being the super-user, and
also for ensuring that you will get errors if the receiving side isn't
being running as the super-user.  To turn off super-user activities, the
super-user can use bf(--no-super).

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

dit(bf(-S, --sparse)) Try to handle sparse files efficiently so they take
up less space on the destination.  Conflicts with bf(--inplace) because it's
not possible to overwrite data in a sparse fashion.

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.

dit(bf(-x, --one-file-system)) This tells rsync to avoid crossing a
filesystem boundary when recursing.  This does not limit the user's ability
to specify items to copy from multiple filesystems, just rsync's recursion
through the hierarchy of each directory that the user specified, and also
the analogous recursion on the receiving side during deletion.  Also keep
in mind that rsync treats a "bind" mount to the same device as being on the
same filesystem.

If this option is repeated, rsync omits all mount-point directories from
the copy.  Otherwise, it includes an empty directory at each mount-point it
encounters (using the attributes of the mounted directory because those of
the underlying mount-point directory are inaccessible).

If rsync has been told to collapse symlinks (via bf(--copy-links) or
bf(--copy-unsafe-links)), a symlink to a directory on another device is
treated like a mount-point.  Symlinks to non-directories are unaffected
by this option.

dit(bf(--existing, --ignore-non-existing)) This tells rsync to skip
updating files that do not exist yet on the destination.  If this option is
combined with the bf(--ignore-existing) option, no files will be updated
(which can be useful if all you want to do is to delete missing files).

dit(bf(--ignore-existing)) This tells rsync to skip updating files that
already exist on the destination.  See also bf(--ignore-non-existing).

dit(bf(--remove-sent-files)) This tells rsync to remove from the sending
side the files and/or symlinks that are newly created or whose content is
updated on the receiving side.  Directories and devices are not removed,
nor are files/symlinks whose attributes are merely changed.

dit(bf(--delete)) This tells rsync to delete extraneous files from the
receiving side (ones that aren't on the sending side), but only for the
directories that are being synchronized.  You must have asked rsync to
send the whole directory (e.g. "dir" or "dir/") without using a wildcard
for the directory's contents (e.g. "dir/*") since the wildcard is expanded
by the shell and rsync thus gets a request to transfer individual files, not
the files' parent directory.  Files that are excluded from transfer are
also excluded from being deleted unless you use the bf(--delete-excluded)
option or mark the rules as only matching on the sending side (see the
include/exclude modifiers in the FILTER RULES section).

Prior to rsync 2.6.7, this option would have no effect unless bf(--recursive)
was in effect.  Beginning with 2.6.7, deletions will also occur when bf(--dirs)
(bf(-d)) is in effect, but only for directories whose contents are being copied.

This option can be dangerous if used incorrectly!  It is a very good idea
to run first using the bf(--dry-run) option (bf(-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 bf(--ignore-errors) option.

The bf(--delete) option may be combined with one of the --delete-WHEN options
without conflict, as well as bf(--delete-excluded).  However, if none of the
--delete-WHEN options are specified, rsync will currently choose the
bf(--delete-before) algorithm.  A future version may change this to choose the
bf(--delete-during) algorithm.  See also bf(--delete-after).

dit(bf(--delete-before)) Request that the file-deletions on the receiving
side be done before the transfer starts.  This is the default if bf(--delete)
or bf(--delete-excluded) is specified without one of the --delete-WHEN options.
See bf(--delete) (which is implied) for more details on file-deletion.

Deleting before the transfer is helpful if the filesystem is tight for space
and removing extraneous files would help to make the transfer possible.
However, it does introduce a delay before the start of the transfer,
and this delay might cause the transfer to timeout (if bf(--timeout) was
specified).

dit(bf(--delete-during, --del)) Request that the file-deletions on the
receiving side be done incrementally as the transfer happens.  This is
a faster method than choosing the before- or after-transfer algorithm,
but it is only supported beginning with rsync version 2.6.4.
See bf(--delete) (which is implied) for more details on file-deletion.

dit(bf(--delete-after)) Request that the file-deletions on the receiving
side be done after the transfer has completed.  This is useful if you
are sending new per-directory merge files as a part of the transfer and
you want their exclusions to take effect for the delete phase of the
current transfer.
See bf(--delete) (which is implied) for more details on file-deletion.

dit(bf(--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 bf(--exclude)).
See the FILTER RULES section for a way to make individual exclusions behave
this way on the receiver, and for a way to protect files from
bf(--delete-excluded).
See bf(--delete) (which is implied) for more details on file-deletion.

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

dit(bf(--force)) This option tells rsync to delete a non-empty directory
when it is to be replaced by a non-directory.  This is only relevant if
deletions are not active (see bf(--delete) for details).

Note for older rsync versions: bf(--force) used to still be required when
using bf(--delete-after), and it used to be non-functional unless the
bf(--recursive) option was also enabled.

dit(bf(--max-delete=NUM)) This tells rsync not to delete more than NUM
files or directories (NUM must be non-zero).
This is useful when mirroring very large trees to prevent disasters.

dit(bf(--max-size=SIZE)) This tells rsync to avoid transferring any
file that is larger than the specified SIZE. The SIZE value can be
suffixed with a string to indicate a size multiplier, and
may be a fractional value (e.g. "bf(--max-size=1.5m)").

The suffixes are as follows: "K" (or "KiB") is a kibibyte (1024),
"M" (or "MiB") is a mebibyte (1024*1024), and "G" (or "GiB") is a
gibibyte (1024*1024*1024).
If you want the multiplier to be 1000 instead of 1024, use "KB",
"MB", or "GB".  (Note: lower-case is also accepted for all values.)
Finally, if the suffix ends in either "+1" or "-1", the value will
be offset by one byte in the indicated direction.

Examples: --max-size=1.5mb-1 is 1499999 bytes, and --max-size=2g+1 is
2147483649 bytes.

dit(bf(--min-size=SIZE)) This tells rsync to avoid transferring any
file that is smaller than the specified SIZE, which can help in not
transferring small, junk files.
See the bf(--max-size) option for a description of SIZE.

dit(bf(-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.

dit(bf(-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 bf([user@]host::module/path), then the
remote shell em(COMMAND) will be used to run an rsync daemon 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 daemon on the remote host.  See the section "USING
RSYNC-DAEMON FEATURES VIA A REMOTE-SHELL CONNECTION" above.

Command-line arguments are permitted in COMMAND provided that COMMAND is
presented to rsync as a single argument.  You must use spaces (not tabs
or other whitespace) to separate the command and args from each other,
and you can use single- and/or double-quotes to preserve spaces in an
argument (but not backslashes).  Note that doubling a single-quote
inside a single-quoted string gives you a single-quote; likewise for
double-quotes (though you need to pay attention to which quotes your
shell is parsing and which quotes rsync is parsing).  Some examples:

quote(
tt(    -e 'ssh -p 2234')nl()
tt(    -e 'ssh -o "ProxyCommand nohup ssh firewall nc -w1 %h %p"')nl()
)

(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 bf(-e).

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

dit(bf(--rsync-path=PROGRAM)) Use this to specify what program is to be run
on the remote machine to start-up rsync.  Often used when rsync is not in
the default remote-shell's path (e.g. --rsync-path=/usr/local/bin/rsync).
Note that PROGRAM is run with the help of a shell, so it can be any
program, script, or command sequence you'd care to run, so long as it does
not corrupt the standard-in & standard-out that rsync is using to
communicate.

One tricky example is to set a different default directory on the remote
machine for use with the bf(--relative) option.  For instance:

quote(tt(    rsync -avR --rsync-path="cd /a/b && rsync" hst:c/d /e/))

dit(bf(-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:

quote(quote(tt(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.  Unlike
rsync's filter/exclude files, these patterns are split on whitespace.
See the bf(cvs(1)) manual for more information.

If you're combining bf(-C) with your own bf(--filter) rules, you should
note that these CVS excludes are appended at the end of your own rules,
regardless of where the bf(-C) was placed on the command-line.  This makes them
a lower priority than any rules you specified explicitly.  If you want to
control where these CVS excludes get inserted into your filter rules, you
should omit the bf(-C) as a command-line option and use a combination of
bf(--filter=:C) and bf(--filter=-C) (either on your command-line or by
putting the ":C" and "-C" rules into a filter file with your other rules).
The first option turns on the per-directory scanning for the .cvsignore
file.  The second option does a one-time import of the CVS excludes
mentioned above.

dit(bf(-f, --filter=RULE)) This option allows you to add rules 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 bf(--filter) options on the command line as you like
to build up the list of files to exclude.

See the FILTER RULES section for detailed information on this option.

dit(bf(-F)) The bf(-F) option is a shorthand for adding two bf(--filter) rules to
your command.  The first time it is used is a shorthand for this rule:

quote(tt(   --filter='dir-merge /.rsync-filter'))

This tells rsync to look for per-directory .rsync-filter files that have
been sprinkled through the hierarchy and use their rules to filter the
files in the transfer.  If bf(-F) is repeated, it is a shorthand for this
rule:

quote(tt(   --filter='exclude .rsync-filter'))

This filters out the .rsync-filter files themselves from the transfer.

See the FILTER RULES section for detailed information on how these options
work.

dit(bf(--exclude=PATTERN)) This option is a simplified form of the
bf(--filter) option that defaults to an exclude rule and does not allow
the full rule-parsing syntax of normal filter rules.

See the FILTER RULES section for detailed information on this option.

dit(bf(--exclude-from=FILE)) This option is related to the bf(--exclude)
option, but it specifies a FILE that contains exclude patterns (one per line).
Blank lines in the file and lines starting with ';' or '#' are ignored.
If em(FILE) is bf(-), the list will be read from standard input.

dit(bf(--include=PATTERN)) This option is a simplified form of the
bf(--filter) option that defaults to an include rule and does not allow
the full rule-parsing syntax of normal filter rules.

See the FILTER RULES section for detailed information on this option.

dit(bf(--include-from=FILE)) This option is related to the bf(--include)
option, but it specifies a FILE that contains include patterns (one per line).
Blank lines in the file and lines starting with ';' or '#' are ignored.
If em(FILE) is bf(-), the list will be read from standard input.

dit(bf(--files-from=FILE)) Using this option allows you to specify the
exact list of files to transfer (as read from the specified FILE or bf(-)
for standard input).  It also tweaks the default behavior of rsync to make
transferring just the specified files and directories easier:

quote(itemize(
  it() The bf(--relative) (bf(-R)) option is implied, which preserves the path
  information that is specified for each item in the file (use
  bf(--no-relative) or bf(--no-R) if you want to turn that off).
  it() The bf(--dirs) (bf(-d)) option is implied, which will create directories
  specified in the list on the destination rather than noisily skipping
  them (use bf(--no-dirs) or bf(--no-d) if you want to turn that off).
  it() The bf(--archive) (bf(-a)) option's behavior does not imply bf(--recursive)
  (bf(-r)), so specify it explicitly, if you want it.
  it() These side-effects change the default state of rsync, so the position
  of the bf(--files-from) option on the command-line has no bearing on how
  other options are parsed (e.g. bf(-a) works the same before or after
  bf(--files-from), as does bf(--no-R) and all other options).
))

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:

quote(tt(   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.  If it
contains "bin/" (note the trailing slash), the immediate contents of
the directory would also be sent (without needing to be explicitly
mentioned in the file -- this began in version 2.6.4).  In both cases,
if the bf(-r) option was enabled, that dir's entire hierarchy would
also be transferred (keep in mind that bf(-r) needs to be specified
explicitly with bf(--files-from), since it is not implied by bf(-a)).
Also note
that the effect of the (enabled by default) bf(--relative) option is to
duplicate only the path info that is read from the file -- it does not
force the duplication of the source-spec path (/usr in this case).

In addition, the bf(--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 transfer).  As a short-cut, you can
specify just a prefix of ":" to mean "use the remote end of the
transfer".  For example:

quote(tt(   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.

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

dit(bf(-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 each temporary
file in the same directory as the associated destination file.

This option is most often used when the receiving disk partition does not
have enough free space to hold a copy of the largest file in the transfer.
In this case (i.e. when the scratch directory in on a different disk
partition), rsync will not be able to rename each received temporary file
over the top of the associated destination file, but instead must copy it
into place.  Rsync does this by copying the file over the top of the
destination file, which means that the destination file will contain
truncated data during this copy.  If this were not done this way (even if
the destination file were first removed, the data locally copied to a
temporary file in the destination directory, and then renamed into place)
it would be possible for the old file to continue taking up disk space (if
someone had it open), and thus there might not be enough room to fit the
new version on the disk at the same time.

If you are using this option for reasons other than a shortage of disk
space, you may wish to combine it with the bf(--delay-updates) option,
which will ensure that all copied files get put into subdirectories in the
destination hierarchy, awaiting the end of the transfer.  If you don't
have enough room to duplicate all the arriving files on the destination
partition, another way to tell rsync that you aren't overly concerned
about disk space is to use the bf(--partial-dir) option with a relative
path; because this tells rsync that it is OK to stash off a copy of a
single file in a subdir in the destination hierarchy, rsync will use the
partial-dir as a staging area to bring over the copied file, and then
rename it into place from there. (Specifying a bf(--partial-dir) with
an absolute path does not have this side-effect.)

dit(bf(-y, --fuzzy)) This option tells rsync that it should look for a
basis file for any destination file that is missing.  The current algorithm
looks in the same directory as the destination file for either a file that
has an identical size and modified-time, or a similarly-named file.  If
found, rsync uses the fuzzy basis file to try to speed up the transfer.

Note that the use of the bf(--delete) option might get rid of any potential
fuzzy-match files, so either use bf(--delete-after) or specify some
filename exclusions if you need to prevent this.

dit(bf(--compare-dest=DIR)) This option instructs rsync to use em(DIR) on
the destination machine as an additional hierarchy to compare destination
files against doing transfers (if the files are missing in the destination
directory).  If a file is found in em(DIR) that is identical to the
sender's file, the file will NOT be transferred to the destination
directory.  This is useful for creating a sparse backup of just files that
have changed from an earlier backup.

Beginning in version 2.6.4, multiple bf(--compare-dest) directories may be
provided, which will cause rsync to search the list in the order specified
for an exact match.
If a match is found that differs only in attributes, a local copy is made
and the attributes updated.
If a match is not found, a basis file from one of the em(DIR)s will be
selected to try to speed up the transfer.

If em(DIR) is a relative path, it is relative to the destination directory.
See also bf(--copy-dest) and bf(--link-dest).

dit(bf(--copy-dest=DIR)) This option behaves like bf(--compare-dest), but
rsync will also copy unchanged files found in em(DIR) to the destination
directory using a local copy.
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.

Multiple bf(--copy-dest) directories may be provided, which will cause
rsync to search the list in the order specified for an unchanged file.
If a match is not found, a basis file from one of the em(DIR)s will be
selected to try to speed up the transfer.

If em(DIR) is a relative path, it is relative to the destination directory.
See also bf(--compare-dest) and bf(--link-dest).

dit(bf(--link-dest=DIR)) This option behaves like bf(--copy-dest), but
unchanged files are hard linked from em(DIR) to the destination directory.
The files must be identical in all preserved attributes (e.g. permissions,
possibly ownership) in order for the files to be linked together.
An example:

quote(tt(  rsync -av --link-dest=$PWD/prior_dir host:src_dir/ new_dir/))

Beginning in version 2.6.4, multiple bf(--link-dest) directories may be
provided, which will cause rsync to search the list in the order specified
for an exact match.
If a match is found that differs only in attributes, a local copy is made
and the attributes updated.
If a match is not found, a basis file from one of the em(DIR)s will be
selected to try to speed up the transfer.

If em(DIR) is a relative path, it is relative to the destination directory.
See also bf(--compare-dest) and bf(--copy-dest).

Note that rsync versions prior to 2.6.1 had a bug that could prevent
bf(--link-dest) from working properly for a non-super-user when bf(-o) was
specified (or implied by bf(-a)).  You can work-around this bug by avoiding
the bf(-o) option when sending to an old rsync.

dit(bf(-z, --compress)) With this option, rsync compresses the file data
as it is sent to the destination machine, which reduces the amount of data
being transmitted -- something that is useful over a slow connection.

Note that this option typically achieves better compression ratios than can
be achieved by using a compressing remote shell or a compressing transport
because it takes advantage of the implicit information in the matching data
blocks that are not explicitly sent over the connection.

dit(bf(--compress-level=NUM)) Explicitly set the compression level to use
(see bf(--compress)) instead of letting it default.  If NUM is non-zero,
the bf(--compress) option is implied.

dit(bf(--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 determine
what ownership to give files. The special uid 0 and the special group
0 are never mapped via user/group names even if the bf(--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 information 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.

dit(bf(--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.

dit(bf(--address)) By default rsync will bind to the wildcard address when
connecting to an rsync daemon.  The bf(--address) option allows you to
specify a specific IP address (or hostname) to bind to.  See also this
option in the bf(--daemon) mode section.

dit(bf(--port=PORT)) This specifies an alternate TCP port number to use
rather than the default of 873.  This is only needed if you are using the
double-colon (::) syntax to connect with an rsync daemon (since the URL
syntax has a way to specify the port as a part of the URL).  See also this
option in the bf(--daemon) mode section.

dit(bf(--sockopts)) This option can provide endless fun for people
who like to tune their systems to the utmost degree. You can set all
sorts of socket options which may make transfers faster (or
slower!). Read the man page for the setsockopt() system call for
details on some of the options you may be able to set. By default no
special socket options are set. This only affects direct socket
connections to a remote rsync daemon.  This option also exists in the
bf(--daemon) mode section.

dit(bf(--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.)

dit(bf(-i, --itemize-changes)) Requests a simple itemized list of the
changes that are being made to each file, including attribute changes.
This is exactly the same as specifying bf(--log-format='%i %n%L').
If you repeat the option, unchanged files will also be output, but only
if the receiving rsync is at least version 2.6.7 (you can use bf(-vv)
with older versions of rsync, but that also turns on the output of other
verbose messages).

The "%i" escape has a cryptic output that is 9 letters long.  The general
format is like the string bf(YXcstpogz), where bf(Y) is replaced by the
type of update being done, bf(X) is replaced by the file-type, and the
other letters represent attributes that may be output if they are being
modified.

The update types that replace the bf(Y) are as follows:

quote(itemize(
  it() A bf(<) means that a file is being transferred to the remote host
  (sent).
  it() A bf(>) means that a file is being transferred to the local host
  (received).
  it() A bf(c) means that a local change/creation is occurring for the item
  (such as the creation of a directory or the changing of a symlink, etc.).
  it() A bf(h) means that the item is a hard link to another item (requires
  bf(--hard-links)).
  it() A bf(.) means that the item is not being updated (though it might
  have attributes that are being modified).
))

The file-types that replace the bf(X) are: bf(f) for a file, a bf(d) for a
directory, an bf(L) for a symlink, a bf(D) for a device, and a bf(S) for a
special file (e.g. named sockets and fifos).

The other letters in the string above are the actual letters that
will be output if the associated attribute for the item is being updated or
a "." for no change.  Three exceptions to this are: (1) a newly created
item replaces each letter with a "+", (2) an identical item replaces the
dots with spaces, and (3) an unknown attribute replaces each letter with
a "?" (this can happen when talking to an older rsync).

The attribute that is associated with each letter is as follows:

quote(itemize(
  it() A bf(c) means the checksum of the file is different and will be
  updated by the file transfer (requires bf(--checksum)).
  it() A bf(s) means the size of the file is different and will be updated
  by the file transfer.
  it() A bf(t) means the modification time is different and is being updated
  to the sender's value (requires bf(--times)).  An alternate value of bf(T)
  means that the time will be set to the transfer time, which happens
  anytime a symlink is transferred, or when a file or device is transferred
  without bf(--times).
  it() A bf(p) means the permissions are different and are being updated to
  the sender's value (requires bf(--perms)).
  it() An bf(o) means the owner is different and is being updated to the
  sender's value (requires bf(--owner) and super-user privileges).
  it() A bf(g) means the group is different and is being updated to the
  sender's value (requires bf(--group) and the authority to set the group).
  it() The bf(z) slot is reserved for future use.
))

One other output is possible:  when deleting files, the "%i" will output
the string "*deleting" for each item that is being removed (assuming that
you are talking to a recent enough rsync that it logs deletions instead of
outputting them as a verbose message).

dit(bf(--log-format=FORMAT)) This allows you to specify exactly what the
rsync client outputs to the user on a per-file basis.  The format is a text
string containing embedded single-character escape sequences prefixed with
a percent (%) character.  For a list of the possible escape characters, see
the "log format" setting in the rsyncd.conf manpage.  (Note that this
option does not affect what a daemon logs to its logfile.)

Specifying this option will mention each file, dir, etc. that gets updated
in a significant way (a transferred file, a recreated symlink/device, or a
touched directory) unless the itemize-changes escape (%i) is included in
the string, in which case the logging of names increases to mention any
item that is changed in any way (as long as the receiving side is at least
2.6.4).  See the bf(--itemize-changes) option for a description of the
output of "%i".

The bf(--verbose) option implies a format of "%n%L", but you can use
bf(--log-format) without bf(--verbose) if you like, or you can override
the format of its per-file output using this option.

Rsync will output the log-format string prior to a file's transfer unless
one of the transfer-statistic escapes is requested, in which case the
logging is done at the end of the file's transfer.  When this late logging
is in effect and bf(--progress) is also specified, rsync will also output
the name of the file being transferred prior to its progress information
(followed, of course, by the log-format output).

dit(bf(--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.

The current statistics are as follows: itemize(
  it() bf(Number of files) is the count of all "files" (in the generic
  sense), which includes directories, symlinks, etc.
  it() bf(Number of files transferred) is the count of normal files that
  were updated via the rsync algorithm, which does not include created
  dirs, symlinks, etc.
  it() bf(Total file size) is the total sum of all file sizes in the transfer.
  This does not count any size for directories or special files, but does
  include the size of symlinks.
  it() bf(Total transferred file size) is the total sum of all files sizes
  for just the transferred files.
  it() bf(Literal data) is how much unmatched file-update data we had to
  send to the receiver for it to recreate the updated files.
  it() bf(Matched data) is how much data the receiver got locally when
  recreating the updated files.
  it() bf(File list size) is how big the file-list data was when the sender
  sent it to the receiver.  This is smaller than the in-memory size for the
  file list due to some compressing of duplicated data when rsync sends the
  list.
  it() bf(File list generation time) is the number of seconds that the
  sender spent creating the file list.  This requires a modern rsync on the
  sending side for this to be present.
  it() bf(File list transfer time) is the number of seconds that the sender
  spent sending the file list to the receiver.
  it() bf(Total bytes sent) is the count of all the bytes that rsync sent
  from the client side to the server side.
  it() bf(Total bytes received) is the count of all non-message bytes that
  rsync received by the client side from the server side.  "Non-message"
  bytes means that we don't count the bytes for a verbose message that the
  server sent to us, which makes the stats more consistent.
)

dit(bf(-8, --8-bit-output)) This tells rsync to leave all high-bit characters
unescaped in the output instead of trying to test them to see if they're
valid in the current locale and escaping the invalid ones.  All control
characters (but never tabs) are always escaped, regardless of this option's
setting.

The escape idiom that started in 2.6.7 is to output a literal backslash (\)
and a hash (#), followed by exactly 3 octal digits.  For example, a newline
would output as "\#012".  A literal backslash that is in a filename is not
escaped unless it is followed by a hash and 3 digits (0-9).

dit(bf(-h, --human-readable)) Output numbers in a more human-readable format.
This makes big numbers output using larger units, with a K, M, or G suffix.  If
this option was specified once, these units are K (1000), M (1000*1000), and
G (1000*1000*1000); if the option is repeated, the units are powers of 1024
instead of 1000.

dit(bf(--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
bf(--partial) option tells rsync to keep the partial file which should
make a subsequent transfer of the rest of the file much faster.

dit(bf(--partial-dir=DIR)) A better way to keep partial files than the
bf(--partial) option is to specify a em(DIR) that will be used to hold the
partial data (instead of writing it out to the destination file).
On the next transfer, rsync will use a file found in this
dir as data to speed up the resumption of the transfer and then delete it
after it has served its purpose.

Note that if bf(--whole-file) is specified (or implied), any partial-dir
file that is found for a file that is being updated will simply be removed
(since
rsync is sending files without using the incremental rsync algorithm).

Rsync will create the em(DIR) if it is missing (just the last dir -- not
the whole path).  This makes it easy to use a relative path (such as
"bf(--partial-dir=.rsync-partial)") to have rsync create the
partial-directory in the destination file's directory when needed, and then
remove it again when the partial file is deleted.

If the partial-dir value is not an absolute path, rsync will add an exclude
rule at the end of all your existing excludes.  This will prevent the
sending of any partial-dir files that may exist on the sending side, and
will also prevent the untimely deletion of partial-dir items on the
receiving side.  An example: the above bf(--partial-dir) option would add
the equivalent of "bf(--exclude=.rsync-partial/)" at the end of any other
filter rules.

If you are supplying your own exclude rules, you may need to add your own
exclude/hide/protect rule for the partial-dir because (1) the auto-added
rule may be ineffective at the end of your other rules, or (2) you may wish
to override rsync's exclude choice.  For instance, if you want to make
rsync clean-up any left-over partial-dirs that may be lying around, you
should specify bf(--delete-after) and add a "risk" filter rule, e.g.
bf(-f 'R .rsync-partial/').  (Avoid using bf(--delete-before) or
bf(--delete-during) unless you don't need rsync to use any of the
left-over partial-dir data during the current run.)

IMPORTANT: the bf(--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 bf(--partial) to be
enabled, but rather it affects where partial files go when bf(--partial) is
specified.  For instance, instead of using bf(--partial-dir=.rsync-tmp)
along with bf(--progress), you could set RSYNC_PARTIAL_DIR=.rsync-tmp in your
environment and then just use the bf(-P) option to turn on the use of the
.rsync-tmp dir for partial transfers.  The only times that the bf(--partial)
option does not look for this environment value are (1) when bf(--inplace) was
specified (since bf(--inplace) conflicts with bf(--partial-dir)), and (2) when
bf(--delay-updates) was specified (see below).

For the purposes of the daemon-config's "refuse options" setting,
bf(--partial-dir) does em(not) imply bf(--partial).  This is so that a
refusal of the bf(--partial) option can be used to disallow the overwriting
of destination files with a partial transfer, while still allowing the
safer idiom provided by bf(--partial-dir).

dit(bf(--delay-updates)) This option puts the temporary file from each
updated file into a holding directory until the end of the
transfer, at which time all the files are renamed into place in rapid
succession.  This attempts to make the updating of the files a little more
atomic.  By default the files are placed into a directory named ".~tmp~" in
each file's destination directory, but if you've specified the
bf(--partial-dir) option, that directory will be used instead.  See the
comments in the bf(--partial-dir) section for a discussion of how this
".~tmp~" dir will be excluded from the transfer, and what you can do if
you wnat rsync to cleanup old ".~tmp~" dirs that might be lying around.
Conflicts with bf(--inplace) and bf(--append).

This option uses more memory on the receiving side (one bit per file
transferred) and also requires enough free disk space on the receiving
side to hold an additional copy of all the updated files.  Note also that
you should not use an absolute path to bf(--partial-dir) unless (1)
there is no
chance of any of the files in the transfer having the same name (since all
the updated files will be put into a single directory if the path is
absolute)
and (2) there are no mount points in the hierarchy (since the
delayed updates will fail if they can't be renamed into place).

See also the "atomic-rsync" perl script in the "support" subdir for an
update algorithm that is even more atomic (it uses bf(--link-dest) and a
parallel hierarchy of files).

dit(bf(-m, --prune-empty-dirs)) This option tells the receiving rsync to get
rid of empty directories from the file-list, including nested directories
that have no non-directory children.  This is useful for avoiding the
creation of a bunch of useless directories when the sending rsync is
recursively scanning a hierarchy of files using include/exclude/filter
rules.

Because the file-list is actually being pruned, this option also affects
what directories get deleted when a delete is active.  However, keep in
mind that excluded files and directories can prevent existing items from
being deleted (because an exclude hides source files and protects
destination files).

You can prevent the pruning of certain empty directories from the file-list
by using a global "protect" filter.  For instance, this option would ensure
that the directory "emptydir" was kept in the file-list:

quote(    --filter 'protect emptydir/')

Here's an example that copies all .pdf files in a hierarchy, only creating
the necessary destination directories to hold the .pdf files, and ensures
that any superfluous files and directories in the destination are removed
(note the hide filter of non-directories being used instead of an exclude):

quote(     rsync -avm --del --include='*.pdf' -f 'hide! */' src/ dest)

If you didn't want to remove superfluous destination files, the more
time-honored options of "--include='*/' --exclude='*'" would work fine
in place of the hide-filter (if that is more natural to you).

dit(bf(--progress)) This option tells rsync to print information
showing the progress of the transfer. This gives a bored user
something to watch.
Implies bf(--verbose) if it wasn't already specified.

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

verb(      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-completion rate (including both
data over the wire and data being matched locally), and the estimated time
remaining in this transfer.

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

verb(     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.

dit(bf(-P)) The bf(-P) option is equivalent to bf(--partial) bf(--progress).  Its
purpose is to make it much easier to specify these two options for a long
transfer that may be interrupted.

dit(bf(--password-file)) This option allows you to provide a password
in a file for accessing a remote rsync daemon. Note that this option
is only useful when accessing an rsync daemon using the built in
transport, 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.

dit(bf(--list-only)) This option will cause the source files to be listed
instead of transferred.  This option is inferred if there is no destination
specified, so you don't usually need to use it explicitly.  However, it can
come in handy for a user that wants to avoid the "bf(-r --exclude='/*/*')"
options that rsync might use as a compatibility kluge when generating a
non-recursive listing, or to list the files that are involved in a local
copy (since the destination path is not optional for a local copy, you
must specify this option explicitly and still include a destination).

dit(bf(--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.

dit(bf(--write-batch=FILE)) Record a file that can later be applied to
another identical destination with bf(--read-batch). See the "BATCH MODE"
section for details, and also the bf(--only-write-batch) option.

dit(bf(--only-write-batch=FILE)) Works like bf(--write-batch), except that
no updates are made on the destination system when creating the batch.
This lets you transport the changes to the destination system via some
other means and then apply the changes via bf(--read-batch).

Note that you can feel free to write the batch directly to some portable
media: if this media fills to capacity before the end of the transfer, you
can just apply that partial transfer to the destination and repeat the
whole process to get the rest of the changes (as long as you don't mind a
partially updated destination system while the multi-update cycle is
happening).

Also note that you only save bandwidth when pushing changes to a remote
system because this allows the batched data to be diverted from the sender
into the batch file without having to flow over the wire to the receiver
(when pulling, the sender is remote, and thus can't write the batch).

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

dit(bf(--protocol=NUM)) Force an older protocol version to be used.  This
is useful for creating a batch file that is compatible with an older
version of rsync.  For instance, if rsync 2.6.4 is being used with the
bf(--write-batch) option, but rsync 2.6.3 is what will be used to run the
bf(--read-batch) option, you should use "--protocol=28" when creating the
batch file to force the older protocol version to be used in the batch
file (assuming you can't upgrade the rsync on the reading system).

dit(bf(-4, --ipv4) or bf(-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 daemon.  See also these options in the bf(--daemon) mode section.

dit(bf(--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
applications 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.
enddit()

manpagesection(DAEMON OPTIONS)

The options allowed when starting an rsync daemon are as follows:

startdit()
dit(bf(--daemon)) This tells rsync that it is to run as a daemon.  The
daemon you start running may be accessed using an rsync client using
the bf(host::module) or bf(rsync://host/module/) syntax.

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.

dit(bf(--address)) By default rsync will bind to the wildcard address when
run as a daemon with the bf(--daemon) option.  The bf(--address) option
allows you to specify a specific IP address (or hostname) to bind to.  This
makes virtual hosting possible in conjunction with the bf(--config) option.
See also the "address" global option in the rsyncd.conf manpage.

dit(bf(--bwlimit=KBPS)) This option allows you to specify a maximum
transfer rate in kilobytes per second for the data the daemon sends.
The client can still specify a smaller bf(--bwlimit) value, but their
requested value will be rounded down if they try to exceed it.  See the
client version of this option (above) for some extra details.

dit(bf(--config=FILE)) This specifies an alternate config file than
the default.  This is only relevant when bf(--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 the super-user; in that case
the default is rsyncd.conf in the current directory (typically $HOME).

dit(bf(--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
bf(daemontools) or AIX's bf(System Resource Controller).
bf(--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.

dit(bf(--port=PORT)) This specifies an alternate TCP port number for the
daemon to listen on rather than the default of 873.  See also the "port"
global option in the rsyncd.conf manpage.

dit(bf(--sockopts)) This overrides the bf(socket options) setting in the
rsyncd.conf file and has the same syntax.

dit(bf(-v, --verbose)) This option increases the amount of information the
daemon logs during its startup phase.  After the client connects, the
daemon's verbosity level will be controlled by the options that the client
used and the "max verbosity" setting in the module's config section.

dit(bf(-4, --ipv4) or bf(-6, --ipv6)) Tells rsync to prefer IPv4/IPv6
when creating the incoming sockets that the rsync daemon will use to
listen for connections.  One of these options may be required in older
versions of Linux to work around an IPv6 bug in the kernel (if you see
an "address already in use" error when nothing else is using the port,
try specifying bf(--ipv6) or bf(--ipv4) when starting the daemon).

dit(bf(-h, --help)) When specified after bf(--daemon), print a short help
page describing the options available for starting an rsync daemon.
enddit()

manpagesection(FILTER RULES)

The filter rules allow for flexible selection of which files to transfer
(include) and which files to skip (exclude).  The rules either directly
specify include/exclude patterns or they specify a way to acquire more
include/exclude patterns (e.g. to read them from a file).

As the list of files/directories to transfer is built, rsync checks each
name to be transferred against the list of include/exclude patterns in
turn, and 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 pattern is found, then the
filename is not skipped.

Rsync builds an ordered list of filter rules as specified on the
command-line.  Filter rules have the following syntax:

quote(
tt(RULE [PATTERN_OR_FILENAME])nl()
tt(RULE,MODIFIERS [PATTERN_OR_FILENAME])nl()
)

You have your choice of using either short or long RULE names, as described
below.  If you use a short-named rule, the ',' separating the RULE from the
MODIFIERS is optional.  The PATTERN or FILENAME that follows (when present)
must come after either a single space or an underscore (_).
Here are the available rule prefixes:

quote(
bf(exclude, -) specifies an exclude pattern. nl()
bf(include, +) specifies an include pattern. nl()
bf(merge, .) specifies a merge-file to read for more rules. nl()
bf(dir-merge, :) specifies a per-directory merge-file. nl()
bf(hide, H) specifies a pattern for hiding files from the transfer. nl()
bf(show, S) files that match the pattern are not hidden. nl()
bf(protect, P) specifies a pattern for protecting files from deletion. nl()
bf(risk, R) files that match the pattern are not protected. nl()
bf(clear, !) clears the current include/exclude list (takes no arg) nl()
)

When rules are being read from a file, empty lines are ignored, as are
comment lines that start with a "#".

Note that the bf(--include)/bf(--exclude) command-line options do not allow the
full range of rule parsing as described above -- they only allow the
specification of include/exclude patterns plus a "!" token to clear the
list (and the normal comment parsing when rules are read from a file).
If a pattern
does not begin with "- " (dash, space) or "+ " (plus, space), then the
rule will be interpreted as if "+ " (for an include option) or "- " (for
an exclude option) were prefixed to the string.  A bf(--filter) option, on
the other hand, must always contain either a short or long rule name at the
start of the rule.

Note also that the bf(--filter), bf(--include), and bf(--exclude) options take one
rule/pattern each. To add multiple ones, you can repeat the options on
the command-line, use the merge-file syntax of the bf(--filter) option, or
the bf(--include-from)/bf(--exclude-from) options.

manpagesection(INCLUDE/EXCLUDE PATTERN RULES)

You can include and exclude files by specifying patterns using the "+",
"-", etc. filter rules (as introduced in the FILTER RULES section above).
The include/exclude rules each specify a pattern that is matched against
the names of the files that are going to be transferred.  These patterns
can take several forms:

itemize(
  it() if the pattern starts with a / then it is anchored to a
  particular spot in the hierarchy of files, otherwise it is matched
  against the end of the pathname.  This is similar to a leading ^ in
  regular expressions.
  Thus "/foo" would match a file called "foo" at either the "root of the
  transfer" (for a global rule) or in the merge-file's directory (for a
  per-directory rule).
  An unqualified "foo" would match any file or directory named "foo"
  anywhere in the tree because the algorithm is applied recursively from
  the
  top down; it behaves as if each path component gets a turn at being the
  end of the file name.  Even the unanchored "sub/foo" would match at
  any point in the hierarchy where a "foo" was found within a directory
  named "sub".  See the section on ANCHORING INCLUDE/EXCLUDE PATTERNS for
  a full discussion of how to specify a pattern that matches at the root
  of the transfer.
  it() if the pattern ends with a / then it will only match a
  directory, not a file, link, or device.

  it() rsync chooses between doing a simple string match and wildcard
  matching by checking if the pattern contains one of these three wildcard
  characters: '*', '?', and '[' .
  it() a '*' matches any non-empty path component (it stops at slashes).
  it() use '**' to match anything, including slashes.
  it() a '?' matches any character except a slash (/).
  it() a '[' introduces a character class, such as [a-z] or [[:alpha:]].
  it() in a wildcard pattern, a backslash can be used to escape a wildcard
  character, but it is matched literally when no wildcards are present.
  it() if the pattern contains a / (not counting a trailing /) or a "**",
  then it is matched against the full pathname, including any leading
  directories. If the pattern doesn't contain a / or a "**", then it is
  matched only against the final component of the filename.
  (Remember that the algorithm is applied recursively so "full filename"
  can actually be any portion of a path from the starting directory on
  down.)
  it() a trailing "dir_name/***" will match both the directory (as if
  "dir_name/" had been specified) and all the files in the directory
  (as if "dir_name/**" had been specified).  (This behavior is new for
  version 2.6.7.)
)

Note that, when using the bf(--recursive) (bf(-r)) option (which is implied by
bf(-a)), every subcomponent of every path is visited from the top down, so
include/exclude patterns get applied recursively to each subcomponent's
full name (e.g. to include "/foo/bar/baz" the subcomponents "/foo" and
"/foo/bar" must not be excluded).
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 section of the
hierarchy.  This is particularly important when using a trailing '*' rule.
For instance, this won't work:

quote(
tt(+ /some/path/this-file-will-not-be-found)nl()
tt(+ /file-is-included)nl()
tt(- *)nl()
)

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: "+ */" (put it somewhere before the
"- *" 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:

quote(
tt(+ /some/)nl()
tt(+ /some/path/)nl()
tt(+ /some/path/this-file-is-found)nl()
tt(+ /file-also-included)nl()
tt(- *)nl()
)

Here are some examples of exclude/include matching:

itemize(
  it() "- *.o" would exclude all filenames matching *.o
  it() "- /foo" would exclude a file called foo in the transfer-root directory
  it() "- foo/" would exclude any directory called foo
  it() "- /foo/*/bar" would exclude any file called bar two
  levels below a directory called foo in the transfer-root directory
  it() "- /foo/**/bar" would exclude any file called bar two
  or more levels below a directory called foo in the transfer-root directory
  it() The combination of "+ */", "+ *.c", and "- *" would include all
  directories and C source files but nothing else.
  it() The combination of "+ foo/", "+ foo/bar.c", and "- *" would include
  only the foo directory and foo/bar.c (the foo directory must be
  explicitly included or it would be excluded by the "*")
)

manpagesection(MERGE-FILE FILTER RULES)

You can merge whole files into your filter rules by specifying either a
merge (.) or a dir-merge (:) filter rule (as introduced in the FILTER RULES
section above).

There are two kinds of merged files -- single-instance ('.') and
per-directory (':').  A single-instance merge file is read one time, and
its rules are incorporated into the filter list in the place of the "."
rule.  For per-directory merge files, rsync will scan every directory that
it traverses for the named file, merging its contents when the file exists
into the current list of inherited rules.  These per-directory rule files
must be created on the sending side because it is the sending side that is
being scanned for the available files to transfer.  These rule files may
also need to be transferred to the receiving side if you want them to
affect what files don't get deleted (see PER-DIRECTORY RULES AND DELETE
below).

Some examples:

quote(
tt(merge /etc/rsync/default.rules)nl()
tt(. /etc/rsync/default.rules)nl()
tt(dir-merge .per-dir-filter)nl()
tt(dir-merge,n- .non-inherited-per-dir-excludes)nl()
tt(:n- .non-inherited-per-dir-excludes)nl()
)

The following modifiers are accepted after a merge or dir-merge rule:

itemize(
  it() A bf(-) specifies that the file should consist of only exclude
  patterns, with no other rule-parsing except for in-file comments.
  it() A bf(+) specifies that the file should consist of only include
  patterns, with no other rule-parsing except for in-file comments.
  it() A bf(C) is a way to specify that the file should be read in a
  CVS-compatible manner.  This turns on 'n', 'w', and '-', but also
  allows the list-clearing token (!) to be specified.  If no filename is
  provided, ".cvsignore" is assumed.
  it() A bf(e) will exclude the merge-file name from the transfer; e.g.
  "dir-merge,e .rules" is like "dir-merge .rules" and "- .rules".
  it() An bf(n) specifies that the rules are not inherited by subdirectories.
  it() A bf(w) specifies that the rules are word-split on whitespace instead
  of the normal line-splitting.  This also turns off comments.  Note: the
  space that separates the prefix from the rule is treated specially, so
  "- foo + bar" is parsed as two rules (assuming that prefix-parsing wasn't
  also disabled).
  it() You may also specify any of the modifiers for the "+" or "-" rules
  (below) in order to have the rules that are read in from the file
  default to having that modifier set.  For instance, "merge,-/ .excl" would
  treat the contents of .excl as absolute-path excludes,
  while "dir-merge,s .filt" and ":sC" would each make all their
  per-directory rules apply only on the sending side.
)

The following modifiers are accepted after a "+" or "-":

itemize(
  it() A "/" specifies that the include/exclude rule should be matched
  against the absolute pathname of the current item.  For example,
  "-/ /etc/passwd" would exclude the passwd file any time the transfer
  was sending files from the "/etc" directory, and "-/ subdir/foo"
  would always exclude "foo" when it is in a dir named "subdir", even
  if "foo" is at the root of the current transfer.
  it() A "!" specifies that the include/exclude should take effect if
  the pattern fails to match.  For instance, "-! */" would exclude all
  non-directories.
  it() A bf(C) is used to indicate that all the global CVS-exclude rules
  should be inserted as excludes in place of the "-C".  No arg should
  follow.
  it() An bf(s) is used to indicate that the rule applies to the sending
  side.  When a rule affects the sending side, it prevents files from
  being transferred.  The default is for a rule to affect both sides
  unless bf(--delete-excluded) was specified, in which case default rules
  become sender-side only.  See also the hide (H) and show (S) rules,
  which are an alternate way to specify sending-side includes/excludes.
  it() An bf(r) is used to indicate that the rule applies to the receiving
  side.  When a rule affects the receiving side, it prevents files from
  being deleted.  See the bf(s) modifier for more info.  See also the
  protect (P) and risk (R) rules, which are an alternate way to
  specify receiver-side includes/excludes.
)

Per-directory rules are inherited in all subdirectories of the directory
where the merge-file was found unless the 'n' modifier was used.  Each
subdirectory's rules are prefixed to the inherited per-directory rules
from its parents, which gives the newest rules a higher priority than the
inherited rules.  The entire set of dir-merge rules are grouped together in
the spot where the merge-file was specified, so it is possible to override
dir-merge rules via a rule that got specified earlier in the list of global
rules.  When the list-clearing rule ("!") is read from a per-directory
file, it only clears the inherited rules for the current merge file.

Another way to prevent a single rule from a dir-merge file from being inherited is to
anchor it with a leading slash.  Anchored rules in a per-directory
merge-file are relative to the merge-file's directory, so a pattern "/foo"
would only match the file "foo" in the directory where the dir-merge filter
file was found.

Here's an example filter file which you'd specify via bf(--filter=". file":)

quote(
tt(merge /home/user/.global-filter)nl()
tt(- *.gz)nl()
tt(dir-merge .rules)nl()
tt(+ *.[ch])nl()
tt(- *.o)nl()
)

This will merge the contents of the /home/user/.global-filter file at the
start of the list and also turns the ".rules" filename into a per-directory
filter file.  All rules read in prior to the start of the directory scan
follow the global anchoring rules (i.e. a leading slash matches at the root
of the transfer).

If a per-directory merge-file is specified with a path that is a parent
directory of the first transfer directory, rsync will scan all the parent
dirs from that starting point to the transfer directory for the indicated
per-directory file.  For instance, here is a common filter (see bf(-F)):

quote(tt(--filter=': /.rsync-filter'))

That rule tells rsync to scan for the file .rsync-filter in all
directories from the root down through the parent directory of the
transfer prior to the start of the normal directory scan of the file in
the directories that are sent as a part of the transfer.  (Note: for an
rsync daemon, the root is always the same as the module's "path".)

Some examples of this pre-scanning for per-directory files:

quote(
tt(rsync -avF /src/path/ /dest/dir)nl()
tt(rsync -av --filter=': ../../.rsync-filter' /src/path/ /dest/dir)nl()
tt(rsync -av --filter=': .rsync-filter' /src/path/ /dest/dir)nl()
)

The first two commands above will look for ".rsync-filter" in "/" and
"/src" before the normal scan begins looking for the file in "/src/path"
and its subdirectories.  The last command avoids the parent-dir scan
and only looks for the ".rsync-filter" files in each directory that is
a part of the transfer.

If you want to include the contents of a ".cvsignore" in your patterns,
you should use the rule ":C", which creates a dir-merge of the .cvsignore
file, but parsed in a CVS-compatible manner.  You can
use this to affect where the bf(--cvs-exclude) (bf(-C)) option's inclusion of the
per-directory .cvsignore file gets placed into your rules by putting the
":C" wherever you like in your filter rules.  Without this, rsync would
add the dir-merge rule for the .cvsignore file at the end of all your other
rules (giving it a lower priority than your command-line rules).  For
example:

quote(
tt(cat <<EOT | rsync -avC --filter='. -' a/ b)nl()
tt(+ foo.o)nl()
tt(:C)nl()
tt(- *.old)nl()
tt(EOT)nl()
tt(rsync -avC --include=foo.o -f :C --exclude='*.old' a/ b)nl()
)

Both of the above rsync commands are identical.  Each one will merge all
the per-directory .cvsignore rules in the middle of the list rather than
at the end.  This allows their dir-specific rules to supersede the rules
that follow the :C instead of being subservient to all your rules.  To
affect the other CVS exclude rules (i.e. the default list of exclusions,
the contents of $HOME/.cvsignore, and the value of $CVSIGNORE) you should
omit the bf(-C) command-line option and instead insert a "-C" rule into
your filter rules; e.g. "--filter=-C".

manpagesection(LIST-CLEARING FILTER RULE)

You can clear the current include/exclude list by using the "!" filter
rule (as introduced in the FILTER RULES section above).  The "current"
list is either the global list of rules (if the rule is encountered while
parsing the filter options) or a set of per-directory rules (which are
inherited in their own sub-list, so a subdirectory can use this to clear
out the parent's rules).

manpagesection(ANCHORING INCLUDE/EXCLUDE PATTERNS)

As mentioned earlier, global include/exclude patterns are anchored at the
"root of the transfer" (as opposed to per-directory patterns, which are
anchored at the merge-file's directory).  If you think of the transfer as
a subtree of names that are being sent from sender to receiver, the
transfer-root is where the tree starts to be duplicated in the destination
directory.  This root governs where patterns that start with a / match.

Because the matching is relative to the transfer-root, changing the
trailing slash on a source path or changing your use of the bf(--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
host).  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:

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

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

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

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

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

manpagesection(PER-DIRECTORY RULES AND DELETE)

Without a delete option, per-directory rules are only relevant on the
sending side, so you can feel free to exclude the merge files themselves
without affecting the transfer.  To make this easy, the 'e' modifier adds
this exclude for you, as seen in these two equivalent commands:

quote(
tt(rsync -av --filter=': .excl' --exclude=.excl host:src/dir /dest)nl()
tt(rsync -av --filter=':e .excl' host:src/dir /dest)nl()
)

However, if you want to do a delete on the receiving side AND you want some
files to be excluded from being deleted, you'll need to be sure that the
receiving side knows what files to exclude.  The easiest way is to include
the per-directory merge files in the transfer and use bf(--delete-after),
because this ensures that the receiving side gets all the same exclude
rules as the sending side before it tries to delete anything:

quote(tt(rsync -avF --delete-after host:src/dir /dest))

However, if the merge files are not a part of the transfer, you'll need to
either specify some global exclude rules (i.e. specified on the command
line), or you'll need to maintain your own per-directory merge files on
the receiving side.  An example of the first is this (assume that the
remote .rules files exclude themselves):

verb(rsync -av --filter=': .rules' --filter='. /my/extra.rules'
   --delete host:src/dir /dest)

In the above example the extra.rules file can affect both sides of the
transfer, but (on the sending side) the rules are subservient to the rules
merged from the .rules files because they were specified after the
per-directory merge rule.

In one final example, the remote side is excluding the .rsync-filter
files from the transfer, but we want to use our own .rsync-filter files
to control what gets deleted on the receiving side.  To do this we must
specifically exclude the per-directory merge files (so that they don't get
deleted) and then put rules into the local files to control what else
should not get deleted.  Like one of these commands:

verb(    rsync -av --filter=':e /.rsync-filter' --delete \ 
        host:src/dir /dest
    rsync -avFF --delete host:src/dir /dest)

manpagesection(BATCH MODE)

Batch mode can be used to apply the same set of updates to many
identical 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 destination tree pathname which is then used
instead of the original path. This is useful when the destination tree
path differs from the original destination tree path.

Generating the batch file once saves having to perform the file
status, 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:

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

quote(
tt($ rsync --write-batch=foo -a /source/dir/ /adest/dir/)nl()
tt($ ssh remote rsync --read-batch=- -a /bdest/dir/ <foo)nl()
)

In these examples, rsync is used to update /adest/dir/ from /source/dir/
and the information to repeat this operation is stored in "foo" and
"foo.sh".  The 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:

itemize(
  it() 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.
  it() 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.
  it() 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
  bf(--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 "bf(--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 a warning (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 bf(-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.  See also the bf(--protocol) option for a way to have the
creating rsync generate a batch file that an older rsync can understand.
(Note that batch files changed format in version 2.6.3, so mixing versions
older than that with newer versions will not work.)

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 bf(--write-batch) changes to bf(--read-batch),
bf(--files-from) is dropped, and the
bf(--filter)/bf(--include)/bf(--exclude) options are not needed unless
one of the bf(--delete) options is specified.

The code that creates the BATCH.sh file transforms any filter/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 bf(--delete) is desired.  A normal
user can ignore this detail and just use the shell script as an easy way
to run the appropriate bf(--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.

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

If bf(--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
example where this might be used is a web site mirror that wishes
ensure the rsync module they copy does not include symbolic links to
bf(/etc/passwd) in the public section of the site.  Using
bf(--copy-unsafe-links) will cause any links to be copied as the file
they point to on the destination.  Using bf(--safe-links) will cause
unsafe links to be omitted altogether.  (Note that you must specify
bf(--links) for bf(--safe-links) to have any effect.)

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

Here's a summary of how the symlink options are interpreted.  The list is
in order of precedence, so if your combination of options isn't mentioned,
use the first line that is a complete subset of your options:

dit(bf(--copy-links)) Turn all symlinks into normal files (leaving no
symlinks for any other options to affect).

dit(bf(--links --copy-unsafe-links)) Turn all unsafe symlinks into files
and duplicate all safe symlinks.

dit(bf(--copy-unsafe-links)) Turn all unsafe symlinks into files, noisily
skip all safe symlinks.

dit(bf(--links --safe-links)) Duplicate safe symlinks and skip unsafe
ones.

dit(bf(--links)) Duplicate all symlinks.

manpagediagnostics()

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:

quote(tt(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 filter patterns, then
try specifying the bf(-vv) option.  At this level of verbosity rsync will
show why each individual file is included or excluded.

manpagesection(EXIT VALUES)

startdit()
dit(bf(0)) Success
dit(bf(1)) Syntax or usage error
dit(bf(2)) Protocol incompatibility
dit(bf(3)) Errors selecting input/output files, dirs
dit(bf(4)) Requested action not supported: an attempt
was made to manipulate 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.
dit(bf(5)) Error starting client-server protocol
dit(bf(6)) Daemon unable to append to log-file
dit(bf(10)) Error in socket I/O
dit(bf(11)) Error in file I/O
dit(bf(12)) Error in rsync protocol data stream
dit(bf(13)) Errors with program diagnostics
dit(bf(14)) Error in IPC code
dit(bf(20)) Received SIGUSR1 or SIGINT
dit(bf(21)) Some error returned by waitpid()
dit(bf(22)) Error allocating core memory buffers
dit(bf(23)) Partial transfer due to error
dit(bf(24)) Partial transfer due to vanished source files
dit(bf(25)) The --max-delete limit stopped deletions
dit(bf(30)) Timeout in data send/receive
enddit()

manpagesection(ENVIRONMENT VARIABLES)

startdit()
dit(bf(CVSIGNORE)) The CVSIGNORE environment variable supplements any
ignore patterns in .cvsignore files. See the bf(--cvs-exclude) option for
more details.
dit(bf(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 bf(-e) option.
dit(bf(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.
dit(bf(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.
dit(bf(USER) or bf(LOGNAME)) The USER or LOGNAME environment variables
are used to determine the default username sent to an rsync daemon.
If neither is set, the username defaults to "nobody".
dit(bf(HOME)) The HOME environment variable is used to find the user's
default .cvsignore file.
enddit()

manpagefiles()

/etc/rsyncd.conf or rsyncd.conf

manpageseealso()

rsyncd.conf(5)

manpagebugs()

times are transferred as *nix time_t values

When transferring to FAT filesystems rsync may re-sync
unmodified files.
See the comments on the bf(--modify-window) option.

file permissions, devices, etc. are transferred as native numerical
values

see also the comments on the bf(--delete) option

Please report bugs! See the website at
url(http://rsync.samba.org/)(http://rsync.samba.org/)

manpagesection(VERSION)

This man page is current for version 2.6.7pre1 of rsync.

manpagesection(CREDITS)

rsync is distributed under the GNU public license.  See the file
COPYING for details.

A WEB site is available at
url(http://rsync.samba.org/)(http://rsync.samba.org/).  The site
includes an FAQ-O-Matic which may cover questions unanswered by this
manual page.

The primary ftp site for rsync is
url(ftp://rsync.samba.org/pub/rsync)(ftp://rsync.samba.org/pub/rsync).

We would be delighted to hear from you if you like this program.

This program uses the excellent zlib compression library written by
Jean-loup Gailly and Mark Adler.

manpagesection(THANKS)

Thanks to Richard Brent, Brendan Mackay, Bill Waite, Stephen Rothwell
and David Bell for helpful suggestions, patches and testing of rsync.
I've probably missed some people, my apologies if I have.

Especial thanks also to: David Dykstra, Jos Backus, Sebastian Krahmer,
Martin Pool, Wayne Davison, J.W. Schultz.

manpageauthor()

rsync was originally written by Andrew Tridgell and Paul Mackerras.
Many people have later contributed to it.

Mailing lists for support and development are available at
url(http://lists.samba.org)(lists.samba.org)