Add hashlittle2() and ensure the hash is never 0

[rsync.git] / rsync.1.md

diff --git a/rsync.1.md b/rsync.1.md
index 2fbc6e1149f3499a6947e7344a13f169e7ef796c..7271839d5690ff5be0c218585ca221caa14eea51 100644 (file)
--- a/rsync.1.md
+++ b/rsync.1.md
@@ -195,6 +195,24 @@ Dedicate a "host1-files" dir to the remote content:
 
 See the [`--trust-sender`](#opt) option for additional details.
 
+CAUTION: it is not particularly safe to use rsync to copy files from a
+case-preserving filesystem to a case-ignoring filesystem.  If you must perform
+such a copy, you should either disable symlinks via `--no-links` or enable the
+munging of symlinks via [`--munge-links`](#opt) (and make sure you use the
+right local or remote option).  This will prevent rsync from doing potentially
+dangerous things if a symlink name overlaps with a file or directory. It does
+not, however, ensure that you get a full copy of all the files (since that may
+not be possible when the names overlap). A potentially better solution is to
+list all the source files and create a safe list of filenames that you pass to
+the [`--files-from`](#opt) option.  Any files that conflict in name would need
+to be copied to different destination directories using more than one copy.
+
+While a copy of a case-ignoring filesystem to a case-ignoring filesystem can
+work out fairly well, if no `--delete-during` or `--delete-before` option is
+active, rsync can potentially update an existing file on the receiveing side
+without noticing that the upper-/lower-case of the filename should be changed
+to match the sender.
+
 ## ADVANCED USAGE
 
 The syntax for requesting multiple files from a remote host is done by
@@ -203,7 +221,12 @@ the hostname omitted.  For instance, all these work:
 
 >     rsync -aiv host:file1 :file2 host:file{3,4} /dest/
 >     rsync -aiv host::modname/file{1,2} host::modname/extra /dest/
->     rsync -aiv host::modname/first ::modname/extra{1,2} /dest/
+>     rsync -aiv host::modname/first ::extra-file{1,2} /dest/
+
+Note that a daemon connection only supports accessing one module per copy
+command, so if the start of a follow-up path doesn't begin with the
+modname of the first path, it is assumed to be a path in the module (such as
+the extra-file1 & extra-file2 that are grabbed above).
 
 Really old versions of rsync (2.6.9 and before) only allowed specifying one
 remote-source arg, so some people have instead relied on the remote-shell
@@ -235,17 +258,19 @@ section below for information on that.)
 Using rsync in this way is the same as using it with a remote shell except
 that:
 
-- you either use a double colon :: instead of a single colon to separate the
-  hostname from the path, or you use an rsync:// URL.
-- the first word of the "path" is actually a module name.
-- the remote daemon may print a message of the day when you connect.
-- if you specify no path name on the remote daemon then the list of accessible
-  paths on the daemon will be shown.
-- if you specify no local destination then a listing of the specified files on
-  the remote daemon is provided.
-- you must not specify the [`--rsh`](#opt) (`-e`) option (since that overrides
-  the daemon connection to use ssh -- see [USING RSYNC-DAEMON FEATURES VIA A
-  REMOTE-SHELL CONNECTION](#) below).
+- Use either double-colon syntax or rsync:// URL syntax instead of the
+  single-colon (remote shell) syntax.
+- The first element of the "path" is actually a module name.
+- Additional remote source args can use an abbreviated syntax that omits the
+  hostname and/or the module name, as discussed in [ADVANCED USAGE](#).
+- The remote daemon may print a "message of the day" when you connect.
+- If you specify only the host (with no module or path) then a list of
+  accessible modules on the daemon is output.
+- If you specify a remote source path but no destination, a listing of the
+  matching files on the remote daemon is output.
+- The [`--rsh`](#opt) (`-e`) option must be omitted to avoid changing the
+  connection style from using a socket connection to [USING RSYNC-DAEMON
+  FEATURES VIA A REMOTE-SHELL CONNECTION](#).
 
 An example that copies all the files in a remote module named "src":
 
@@ -555,11 +580,14 @@ expand it.
 
 0.  `--version`, `-V`
 
-    Print the rsync version plus other info and exit.
+    Print the rsync version plus other info and exit.  When repeated, the
+    information is output is a JSON format that is still hum-readable (client
+    side only).
 
-    The output includes the default list of checksum algorithms, the default
-    list of compression algorithms, a list of compiled-in capabilities, a link
-    to the rsync web site, and some license/copyright info.
+    The output includes a list of compiled-in capabilities, a list of
+    optimizations, the default list of checksum algorithms, the default list of
+    compression algorithms, the default list of daemon auth digests, a link to
+    the rsync web site, and a few other items.
 
 0.  `--verbose`, `-v`
 
@@ -1702,6 +1730,9 @@ expand it.
     - `xxh64` (aka `xxhash`)
     - `md5`
     - `md4`
+    - `sha1`
+    - `sha256`
+    - `sha512`
     - `none`
 
     Run `rsync --version` to see the default checksum list compiled into your