Rsync 3.1.0 has been finally announced on September 28th, since the last Rsync 3.0.9 was released two years ago.

This is a feature release that improves performance, provides several new options, and fixes a few bugs along the way.

What’s new in Rsync 3.1.0:

OUTPUT CHANGES:

• Output numbers in 3-digit groups by default (e.g. 1,234,567). See the --human-readable option for a way to turn it off. See also the daemon’s “log format” parameter and related command-line options (including --out-format) for a modifier that can be used to request digit-grouping or human-readable output in log escapes. (Note that log output is unchanged by default.)
• The --list-only option is now affected by the --human-readable setting. It will display digit groupings by default, and unit suffixes if higher levels of readability are requested. Also, the column width for the size output has increased from 11 to 14 characters when human readability is enabled. Use --no-h to get the old-style output and column size.
• The output of the --progress option has changed: the string “xfer” was shortened to “xfr”, and the string “to-check” was shortened to “to-chk”, both designed to make room for the (by default) wider display of file size numbers without making the total line-length longer. Also, when incremental recursion is enabled, the string “ir-chk” will be used instead of “to-chk” up until the incremental-recursion scan is done, letting you know that the value to check and the total value will still be increasing as new files are found.
• Enhanced the --stats output: 1) to mention how many files were created (protocol >= 28), 2) to mention how many files were deleted (a new line for protocol 31, but only output when --delete is in effect), and 3) to follow the file-count, created-count, and deleted-count with a subcount list that shows the counts by type. The wording of the transferred count has also changed so that it is clearer that it is only a count of regular files.

BUG FIXES:

• Fixed a bug in the iconv code when EINVAL or EILSEQ is returned with a full output buffer.
• Fixed some rare bugs in --iconv processing that might cause a multibyte character to get translated incorrectly.
• Fixed a bogus “vanished file” error if some files were specified with “./” prefixes and others were not.
• Fixed a bug in --sparse where an extra gap could get inserted after a partial write.
• Changed the way --progress overwrites its prior output in order to make it nearly impossible for the progress to get overwritten by an error.
• Improved the propagation of abnormal-exit error messages. This should help the client side to receive errors from the server when it is exiting abnormally, and should also avoid dying with an “connection unexpectedly closed” exit when the closed connection is really expected.
• The sender now checks each file it plans to remove to ensure that it hasn’t changed from the first stat’s info. This helps to avoid losing file data when the user is not using the option in a safe manner.
• Fixed a data-duplication bug in the compress option that made compression less efficient. This improves protocol 31 onward, while behaving in a compatible (buggy) manner with older rsync protocols.
• When creating a temp-file, rsync is now a bit smarter about it dot-char choices, which can fix a problem on OS X with names that start with “..”.
• Rsync now sets a cleanup flag for --inplace and --append transfers that will flush the write buffer if the transfer aborts. This ensures that more received data gets written out to the disk on an aborted transfer (which is quite helpful on a slow, flaky connection).
• The reads that map_ptr() now does are aligned on 1K boundaries. This helps some filesystems and/or files that don’t like unaligned reads.
• Fix an issue in the msleep() function if time jumps backwards.
• Fix daemon-server module-name splitting bug where an arg would get split even if --protect-args was used.

ENHANCEMENTS:

• Added the --remote-option=OPT (-M OPT) command-line option that is useful for things like sending a remote --log-file=FILE or --fake-super option.
• Added the --info=FLAGS and --debug=FLAGS options to allow finer-grained control over what is output. Added an extra type of --progress output using --info=progress2.
• The --msgs2stderr option can help with debugging rsync by allowing the debug messages to get output to stderr rather than travel via the socket protocol.
• Added the --delete-missing-args and --ignore-missing-args options to either delete or ignore user-specified files on the receiver that are missing on the sender (normally the absence of user-specified files generates an error).
• Added a “T” (terabyte) category to the --human-readable size suffixes.
• Added the --usermap/--groupmap/--chown options for manipulating file ownership during the copy.
• Added the “%C” escape to the log-output handling, which will output the MD5 checksum of any transferred file, or all files if --checksum was specified (when protocol 30 or above is in effect).
• Added the “reverse lookup” parameter to the rsync daemon config file to allow reverse-DNS lookups to be disabled.
• Added a forward-DNS lookup for the daemon’s hosts allow/deny config. Can be disabled via “forward lookup” parameter (defaults to enabled).
• Added a way for more than one group to be specified in the daemon’s config file, including a way to specify that you want all of the specified user’s groups without having to name them. Also changed the daemon to complain about an inability to set explicitly-specified uid/gid values, even when not run by a super-user.
• The daemon now tries to send the user the error messages from the pre-xfer exec script when it fails.
• Improved the use of alt-dest options into an existing hierarchy of files: If a match is found in an alt-dir, it takes precedence over an existing file. (We’ll need to wait for a future version before attribute-change on otherwise unchanged files are safe when using an existing hierarchy.)
• Added per-user authorization options and group-authorization support to the daemon’s “auth users” parameter.
• Added a way to reference environment variables in a daemon’s config file (using %VAR% references).
• When replacing a non-dir with a symlink/hard-link/device/special-file, the update should now be done in an atomic manner.
• Avoid re-sending xattr info for hard-linked files w/the same xattrs (protocol 31).
• The backup code was improved to use better logic maintaining the backup directory hierarchy. Also, when a file is being backed up, rsync tries to hard-link it into place so that the upcoming replacement of the destination file will be atomic (for the normal, non-inplace logic).
• Added the ability to synchronize nano-second modified times.
• Added a few more default suffixes for the “dont compress” settings.
• Added the checking of the RSYNC_PROTECT_ARGS environment variable to allow the default for the --protect-args command-line option to be overridden.
• Added the --preallocate command-line option.
• Allow --password-file=- to read the password from stdin (filename “-“).
• Rsync now comes packaged with an rsync-ssl helper script that can be used to contact a remote rsync daemon using a piped-stunnel command. It also includes an stunnel config file to run the server side to support ssl daemon connections. See the packaging/lsb/rsync.spec file for one way to package the resulting files (Suggestions for how to make this even easier to install & use are welcomed.)
• Improved the speed of some --inplace updates when there are lots of identical checksum blocks that end up being unusable.
• Added the --outbuf=N|L|B option for choosing the output buffering.
• Repeating the --fuzzy option now causes the code to look for fuzzy matches inside alt-dest directories too.
• The --chmod option now supports numeric modes, e.g. --chmod=644,D755
• Added some Solaris xattr code.
• Made an rsync daemon (the listening process) exit with a 0 status when it was signaled to die. This helps launchd.
• Improved the RSYNC_* environment variables for the pre-xfer exec script: when a daemon is sent multiple request args, they are now joined into a single return value (separated by spaces) so that the RSYNC_REQUEST environment variable is accurate for any “pre-xfer exec”. The values in RSYNC_ARG# vars are no longer truncated at the “.” arg (prior to the request dirs/files), so that all the requested values are also listed (separately) in RSYNC_ARG# variables.

EXTRAS:

• Added an “instant-rsyncd” script to the support directory, which makes it easy to configure a simple rsync daemon in the current directory.
• Added the “mapfrom” and “mapto” scripts to the support directory, which makes it easier to do user/group mapping in a local transfer based on passwd/group files from another machine.
• There’s a new, improved version of the lsh script in the support dir: it’s written in perl and supports -u without resorting to using sudo (when run as root). The old shell version is now named lsh.sh.
• There is a helper script named rsync-slash-strip in the support directory for anyone that wants to change the way rsync handles args with trailing slashes. (e.g. arg/ would get stripped to arg while arg/. would turn into arg/).

INTERNAL:

• The I/O code was rewritten to be simpler and do bigger buffered reads over the socket. The I/O between the receiver and the generator was changed to be standard multiplexed-I/O (like that over the socket).
• The sender tries to use any dead time while the generator is looking for files to transfer in order to do sender-side directory scanning in a more parallel manner.
• A daemon can now inform a client about a daemon-configured timeout value so that the client can assist in the keep-alive activity (protocol 31).
• The filter code received some refactoring to make it more extendible, to read better, and do better sanity checking.
• Really big numbers are now output using our own big-num routine rather than casting them to a double and using a %.0f conversion.
• The pool_alloc library has received some minor improvements in alignment handling.
• Added init_stat_x() function to avoid duplication of acl/xattr init code.
• The included zlib was upgraded from 1.2.3 to 1.2.8.
• Rsync can now be compiled to use an unmodified zlib library instead of the tweaked one that is included with rsync. This will eventually become the default, at which point we’ll start the countdown to removing the included zlib. Until then, feel free to configure using: ./configure --with-included-zlib=no

DEVELOPER RELATED:

• Added more conditional debug output.
• Fixed some build issues for android and minix.

The source tar is available here: rsync-3.1.0.tar.gz (signature), with a tar file of the “patches” directory now released in a separate file: rsync-patches-3.1.0.tar.gz (signature), and the diffs from version 3.0.9 are available here: rsync-3.0.9-3.1.0.diffs.gz (signature).