Rsync: Filename Conversion, IP Version Preference, and Checksum Seed

"--protocol=28" when cre‐ ating 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). --iconv=CONVERT_SPEC Rsync can convert filenames between character sets using this op‐ tion. Using a CONVERT_SPEC of "." tells rsync to look up the de‐ fault character‐set via the locale setting. Alternately, you can fully specify what conversion to do by giving a local and a re‐ mote charset separated by a comma in the order --iconv=LOCAL,RE‐ MOTE, e.g. --iconv=utf8,iso88591. This order ensures that the option will stay the same whether you’re pushing or pulling files. Finally, you can specify either --no‐iconv or a CON‐ VERT_SPEC of "-" to turn off any conversion. The default setting of this option is site‐specific, and can also be affected via the RSYNC_ICONV environment variable. For a list of what charset names your local iconv library sup‐ ports, you can run "iconv --list". If you specify the --secluded‐args (-s) option, rsync will trans‐ late the filenames you specify on the command‐line that are being sent to the remote host. See also the --files‐from option. Note that rsync does not do any conversion of names in filter files (including include/exclude files). It is up to you to en‐ sure that you’re specifying matching rules that can match on both sides of the transfer. For instance, you can specify extra in‐ clude/exclude rules if there are filename differences on the two sides that need to be accounted for. When you pass an --iconv option to an rsync daemon that allows it, the daemon uses the charset specified in its "charset" con‐ figuration parameter regardless of the remote charset you actu‐ ally pass. Thus, you may feel free to specify just the local charset for a daemon transfer (e.g. --iconv=utf8). --ipv4, -4 or --ipv6, -6 Tells rsync to prefer IPv4/IPv6 when creating sockets or running ssh. This affects sockets that rsync has direct control over, such as the outgoing socket when directly contacting an rsync daemon, as well as the forwarding of the -4 or -6 option to ssh when rsync can deduce that ssh is being used as the remote shell. For other remote shells you’ll need to specify the "--rsh SHELL -4" option directly (or whatever IPv4/IPv6 hint op‐ tions it uses). See also the daemon version of these options. If rsync was compiled without support for IPv6, the --ipv6 option will have no effect. The rsync --version output will contain "no IPv6" if is the case. --checksum‐seed=NUM Set the checksum seed to the integer NUM. This 4 byte checksum seed is included in each block and MD4 file checksum calculation (the more modern MD5 file checksums don’t use a seed). By de‐ fault 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 repeat‐ able block checksums, or in the case where the user wants a more random checksum seed. Setting NUM to 0 causes rsync to use the default of time() for checksum seed. DAEMON OPTIONS The options allowed when starting an rsync daemon are as follows:

This section of the rsync documentation details options related to filename conversion with `--iconv=CONVERT_SPEC`, specifying IP version preference with `--ipv4, -4` or `--ipv6, -6`, and setting the checksum seed with `--checksum-seed=NUM`. The `--iconv` option allows converting filenames between character sets, `--ipv4/--ipv6` influences socket creation and SSH usage, and `--checksum-seed` sets a specific seed for checksum calculations, useful for repeatable checksums or increased randomness.