.TH REPL 1
.SH NAME
new, sync, scan \- peer to peer replica management
.SH SYNOPSIS
.B repl/new
.I repl
.I id
.I dir
[
.IR excldir ...
]
.br
.B repl/sync
[
.B -N
]
[
.B -12lrn
]
.I repl1
.I repl2
[
.IR dir ...
]
.br
.B repl/scan
.I repl
.SH DESCRIPTION
These programs provide a simplified user interface to
the peer-to-peer replica management system described in
.IR repl (8).
Each peer is called a replica and holds a
replicated file tree.
Any number of replicas can be defined and
any pair can be synchronized at any time. There is no centralized
server nor there is a synchronization order required to detect
conflicts.
.PP
Each replica is described by a
simple
.IR rc (1)
script that identifies the file tree and related
.IR repl (8)
information. The programs try to find configuration files
at
.B $home/lib/repl
and
.B /lib/repl
unless a path is supplied.
.PP
.I New
defines a new replica
.I repl
for the given directory,
using the given identifier. The identifier must be a
lower case letter and must be unique for each peer of a
replicated tree. The file
.I repl
created by the script is used later as an argument
for 
.I sync
and
.IR scan .
The optional
.I excldir
arguments
are directories excluded from
.I dir
for replication purposes. See the examples below.
.PP
.I Sync
synchronizes changes between replicas.
Replicas are identified by the configuration
files created by
.IR new .
Before synchronizing,
.I sync
scans both file trees for changes unless
flag
.B -N
is given.
Scan can be performed separately by using the
.I scan
script.
If any
.I dir
is supplied, relative to the top-dir of a replica,
synchronization applies only to it.
.PP
.I Sync
flag
.B -n
performs a dry run to report changes between both replicas
without synchronizing them (scan is still performed for both).
The flag
.B -l
can be used to synchronize just the left replica (in command line
order) with respect to the other. Flag
.B -r
does the same for the right replica.
.PP
Flags
.B -1
and
.B -2
can be used to resolve conflicts in favor of the first replica (the left one)
and in favor of the second one (the right one).
When there are different conflicts to be gained by different replicas,
one replica can be updated by hand, and then used as the prefered to
settle down all the conflicts.
.SH EXAMPLE
This defines for the system file tree, excluding
.B /usr
and
.BR /dist ,
a replica called
.BR a .
Then we define another replica called
.B b
for a laptop.
.EX
	; repl/new /dist/sys a /root /usr /dist
	replica /dist/sys defined.
	; repl/new /dist/laptop b /fossil /usr /dist
	replica /dist/laptop defined.
.EE
.LP
Synchronice the laptop resolving any conflict in favor
of the system
.EX
	; repl/sync -r1 /dist/sys /dist/laptop
.EE
.SH SOURCE
.B /sys/src/cmd/repl
.SH SEE ALSO
.IR repl (8),
.IR replica (1).
.SH BUGS
Append only files are not synchronized to prevent duplication
of file contents.