These two commands allow distribution of updates (eg, to the Inferno tree)
based on a log of changes since a previous update.
system is the primary for a set of files, and one or more
systems maintain replicas of that set,
although in some applications server and client might be the same machine.
is run on a client, to update the file tree rooted at
The server's version of the tree is rooted at
on the client,
typically by being mounted there (see
takes the current state of the replica from the entries in
and applies a set of changes represented by log entries read from its standard input.
Those entries are provided by the server.
Each change is examined to see whether the file to which it applies is in the expected state.
If so, the change is applied without comment; otherwise, there is a conflict caused by
a local change to the replica tree independently from the primary.
diagnoses the conflict and does not apply the change.
It accepts the following options:
- Resolve inconsistencies in favour of the client: leave the replica as is.
- Exit with an error status on any error, including inconsistency between client and server.
- Print on standard output a list of changes that would be made, and list any conflicts,
but do not change the tree or update the log.
- Resolve inconsistencies in favour of the server: make the replica match the server's state.
- Make file ownership in the replica match that on the server.
- Make group ownership in the replica match that on the server.
- Print a summary of each log entry as it is examined.
- -T timefile
- Read a time and sequence number from
and apply only log entries with stamps greater than that.
On successful completion, if the
option is not given, update the
with the stamp of the last log entry processed successfully.
The scope of an update in a tree can be restricted to a particular set of
listed on the command line.
They should all be relative path names.
is run on a server to produce a sequence of log entries representing changes
to the primary tree since a previous log was produced.
It can also be run on a client to see how its replica state differs from that recorded in a log.
It accepts the following options:
- -p proto
as the prototype for the file system, as described by
- -r root
- The replica is rooted at
the current directory,
- -t now gen
- Make log entries use time
and initial sequence number
The defaults are the current time and 0.
- Produce output only for content and metadata changes, not additions or deletions.
- -x path
and its subtrees from consideration.
produces log entries describing changes, additions and deletions to all files in
but the scope can be limited by giving a different
explicitly listing trees to consider as
on the command line, and
by giving one or more
options to exclude particular paths,
in any desired combination.
- Log file format
A log file is a text file with one line representing each change to the tree.
Each line has the form:
- time gen verb path serverpath mode uid gid mtime length
- time, gen
- are decimal numbers that order the sequence of requests:
is typically the time in seconds of the epoch at which the entry was made;
is a monotonically increasing sequence number
- is an action:
- add file
- change the contents of file
- change the metadata (permissions, ownership) for
- the name of the file on the client
- the name of the file on the server with the contents for
when the server and client file names are the same
- mode, uid, gid, length, mtime
- the resulting metadata (except for
where the metadata is that for the file to be deleted)
- is the MD5 checksum of the file's contents