unison-2.48.3(1) a file-synchronization tool for Unix and Windows


unison-2.48.3 [options]
unison-2.48.3 root1 root2 [options]
unison-2.48.3 profilename [options]
unison-2.48.3-gtk [options]


This manual page briefly documents Unison, and was written for the Debian GNU/Linux distribution because the original program does not have a manual page. For a full description, please refer to the inbuilt documentation or the manuals in /usr/share/doc/unison/. The unison-2.48.3-gtk binary has similar command-line options, but allows the user to select and create profiles and configure options from within the program.

Unison is a file-synchronization tool for Unix and Windows. It allows two replicas of a collection of files and directories to be stored on different hosts (or different disks on the same host), modified separately, and then brought up to date by propagating the changes in each replica to the other.

Unison offers several advantages over various synchronization methods such as CVS, Coda, rsync, Intellisync, etc. Unison can run on and synchronize between Windows and many UNIX platforms. Unison requires no root privileges, system access or kernel changes to function. Unison can synchronize changes to files and directories in both directions, on the same machine, or across a network using ssh or a direct socket connection.

Transfers are optimised using a version of the rsync protocol, making it ideal for slower links. Unison has a clear and precise specification, and is resilient to failure due to its careful handling of the replicas and its private structures.

The two roots can be specified using an URI or a path. The URI must follow the convention: protocol://[user@][host][:port][/path]. The protocol part can be file, socket, ssh or rsh.


All Unison options are long, starting with one dash (`-') only. A summary of options is included here. For a complete description, see the inbuilt documentation or the manuals in /usr/share/doc/unison/.
automatically accept default (nonconflicting) actions
batch mode: ask no questions at all
-doc xxx
show documentation ('-doc topics' lists topics)
use appropriate options for FAT filesystems
synchronize group attributes
-ignore xxx
add a pattern to the ignore list
-ignorenot xxx
add a pattern to the ignorenot list
-nocreation xxx
prevent file creations on one replica
-nodeletion xxx
prevent file deletions on one replica
-noupdate xxx
prevent file updates and deletions on one replica
synchronize owner
-path xxx
path to synchronize
-perms n
part of the permissions which is synchronized
-root xxx
root of a replica (should be used exactly twice)
print nothing except error messages
suppress status messages
exit immediately after the connection to the server
synchronize modification times
print version and exit
-addprefsto xxx
file to add new prefs to
add version number to name of unison on server
-backup xxx
add a pattern to the backup list
-backupcurr xxx
add a pattern to the backupcurr list
-backupcurrnot xxx
add a pattern to the backupcurrnot list
-backupdir xxx
directory for storing centralized backups
-backuploc xxx
where backups are stored ('local' or 'central')
-backupnot xxx
add a pattern to the backupnot list
-backupprefix xxx
prefix for the names of backup files
keep backup copies of all files (see also 'backup')
-backupsuffix xxx
a suffix to be added to names of backup files
-clientHostName xxx
set host name of client
ask about whole-replica (or path) deletes (default true)
ask for confirmation before committing results of a merge
suppress the 'contacting server' message during startup
-copymax n
maximum number of simultaneous copyprog transfers
keep copies of conflicting files
-copyprog xxx
external program for copying large files
-copyprogrest xxx
variant of copyprog for resuming partial transfers
-copyquoterem xxx
add quotes to remote file name for copyprog (true/false/default)
-copythreshold n
use copyprog on files bigger than this (if >=0, in Kb)
-debug xxx
debug module xxx ('all' -> everything, 'verbose' -> more)
-diff xxx
set command for showing differences between files
when set, never use the chmod system call
do not change terminal settings in text UI
-fastcheck xxx
do fast update detection (true/false/default)
skip computing fingerprints for new files (experts only!)
-follow xxx
add a pattern to the follow list
-force xxx
force changes from this replica to the other
-forcepartial xxx
add a pattern to the forcepartial list
force half-duplex communication with the server
-height n
height (in lines) of main window in graphical interface
-host xxx
bind the socket to this host name in server socket mode
ignore existing archive files
-ignorecase xxx
identify upper/lowercase filenames (true/false/default)
ignore inode number changes when detecting updates
ignore locks left over from previous run (dangerous!)
-immutable xxx
add a pattern to the immutable list
-immutablenot xxx
add a pattern to the immutablenot list
-key xxx
define a keyboard shortcut for this profile (in some UIs)
kill server when done (even when using sockets)
-label xxx
provide a descriptive string label for this profile
-links xxx
allow the synchronization of symbolic links (true/false/default)
record actions in logfile (default true)
-logfile xxx
logfile name
-maxbackups n
number of backed up versions of a file
-maxerrors n
maximum number of errors before a directory transfer is aborted
-maxsizethreshold n
prevent transfer of files bigger than this (if >=0, in Kb)
-maxthreads n
maximum number of simultaneous file transfers
-merge xxx
add a pattern to the merge list
-mountpoint xxx
abort if this path does not exist
-nocreationpartial xxx
add a pattern to the nocreationpartial list
-nodeletionpartial xxx
add a pattern to the nodeletionpartial list
-noupdatepartial xxx
add a pattern to the noupdatepartial list
don't map uid/gid values by user/group names
-prefer xxx
choose this replica's version for conflicting changes
-preferpartial xxx
add a pattern to the preferpartial list
-repeat xxx
synchronize repeatedly (text interface only)
-retry n
re-try failed synchronizations N times (text ui only)
-rootalias xxx
register alias for canonical root names
-rsrc xxx
synchronize resource forks (true/false/default)
activate the rsync transfer mode (default true)
run internal tests and exit
-servercmd xxx
name of unison executable on remote server
show 'true names' (for rootalias) of roots and archive
-socket xxx
act as a server on a socket
list changed files by size, not name
-sortfirst xxx
add a pattern to the sortfirst list
-sortlast xxx
add a pattern to the sortlast list
list new before changed files
-sshargs xxx
other arguments (if any) for remote shell command
-sshcmd xxx
path to the ssh executable
use a streaming protocol for transferring file contents (default true)
-ui xxx
select UI ('text' or 'graphic'); command-line only
-unicode xxx
assume Unicode encoding in case insensitive mode
when set, use a file watcher process to detect changes (default true)
optimize transfers using local copies (default true)

Some preferences are just boolean flags. Others take numeric or string arguments, indicated in the preferences list by n or xxx. Most of the string preferences can be given several times; the arguments are accumulated into a list internally.


Options are automatically extracted from `unison -help'. The rest of this manual page was written by Robert McQueen <[email protected]>, for the Debian GNU/Linux system (but may be used by others).