NAME¶
mddiff - computes diff for maildirs
SYNOPSIS¶
mddiff [--max-mailno mno] [--db-file dbf] [-l|--list] [-s|--symlink]
[ --exclude globexpr] [-v|--verbose] [-d|--dry-run]
[ -n|--no-delete] [--no-move] [--help] [--sha1sum] paths
DESCRIPTION¶
mddiff computes the delta from an old status of a maildir (previously
recorded in a support file, called db file) and the current status, generating
a set of commands (a diff) that a third party software can apply to
synchronize a (eventually remote) copy of the maildir.
If
paths is a single file name, and that file is a fifo,
mddiff
reads from it file names separated by new line and outputs the sha1 of its
header and body separated by space.
$ mddiff /tmp/fifo_for_mddiff
806a0ffe4f29766effd764... 463e543da9dac8e298...
582cbb6a5cd3ce13965c8c... 8fa60a7458b1157193...
...
If
paths is a single file name, and that file is a fifo, and the
-s option is passed,
mddiff reads from that fifo two lines at a
time, respectively a source name and a target name. It then creates a symlink
named as as the target name pointing to the source name. If some dictories
need to be created in order to create the symlink, this is also done.
mddiff will print 'OK' on stdout to signal a success, 'ERROR' to signal
an error.
If
paths is a list of directories,
mddiff outputs a list of
actions a client has to perform to synchronize a copy of the same maildirs.
This set of actions is relative to a previous status of the maildir stored in
the db file. The input directories are traversed recursively, and every file
encountered inside directories named cur/ and new/ is a potential mail message
(if it contains no \n\n it is skipped).
$ mddiff ~/Mail/
ADD ~/Mail/cur/1239038050.14937_1.garfield:2,S 66532ebb05b252e...
...
Every client (endpoint using
mddiff for synchronization) must use a
different db-file, and the db-file is strictly related with the set of
directories given as arguments, and should not be used with a different
directory set. Adding items to the directory set is safe, while removing them
may not do what you want (delete actions are generated).
mddiff does not alter the
dbf file, it generates a new one called
dbf.new. It is up to the higher level tool
smd-server(1) to rename
dbf.new to
dbf in case the other endpoint successfully applied the
diff.
The
--exclude option tells
mddiff to ignore all
paths
matching the given
glob(7) expression. This option can be passed
multiple times. Matching is performed using
fnmatch(3) with no special
flags, thus '*' and '?' match any character including '/'. Matching is
performed when a directory is entered. If the match is successful, the
directory and all its subedirectories are skipped.
The
--no-delete option tells
mddiff to not output a DELETE action
for files that disappear. Note that a DELETE action is anyway generated for
files that are moved (i.e. move is COPY plus DELETE). The result is that
deletions are not propagated to the other endpoint.
OPTIONS¶
- --max-mailno mno
- Estimation of max mail message number (defaults to the number of messages
in the db-file + 1000 or 500000 if there is no db-file). You may want to
decrease it for the first run on small systems. It is anyway increased
automatically when needed
- --db-file dbf
- Name of the cache for the endpoint (default db.txt)
- --exclude globexpr
- Exclude paths maching the given expression
- --sha1sum
- Behaves like the sha1sum utility
- --mkdir-p
- Behaves like mkdir -p
- --mkfifo
- Behaves like mkfifo
- -l --list
- Only list the mailboxes recursively contained in paths
- -s --symlink
- Create symlinks for paths read on the input fifo
- -v --verbose
- Increase program verbosity (printed on stderr)
- -d --dry-run
- Do not generate a new db-file
- -n --no-delete
- Do not track deleted files
- --no-move
- Do not generate MOVE (only COPY + DELETE)
- --help
- This help screen
NOTES¶
mddiff is a low level utility, used by smd-server and smd-client. You
should use higher level tools like
smd-pull(1),
smd-push(1) and
smd-loop(1)
SEE ALSO¶
smd-client(1),
smd-server(1),
smd-pull(1),
smd-push(1),
smd-loop(1)
AUTHOR¶
Enrico Tassi <gares@fettunta.org>