[Monotone-devel] maildir assistant

[Glen Ditchfield]

This lua script looks through a maildir directory to find files that have been
moved, renamed, or deleted, and executes monotone commands to record the 
changes. 
   (jack-monotone posted a script to do much the same thing, using inodes: 
http://lists.gnu.org/archive/html/monotone-devel/2005-09/msg00234.html)

#!/usr/bin/env lua

if arg.n > 1 or (arg.n == 1 and (arg[1] == "-h" or arg[1] == "--help")) then 
    print("Usage: " .. arg[0] .. " [-h | --help | MAILDIR]");
    print("Execute 'monotone drop' and 'monotone rename' commands to ");
    print("compensate for changes made to MAILDIR by a mail reader.");
    print("  MAILDIR\tRelative path from the top of the working directory");
    print("         \tto a maildir directory.  (Default: \"Mail\").");
    if arg.n == 1 then os.exit(0);
    else os.exit(1);
    end
end

if arg.n == 1 then 
    maildir = arg[1];
else
    maildir = "Mail";
end

-- Maildirs contain e-mail messages in separate files.  The file names consist
-- of a unique string in "x.y.z" form and an optional suffix that starts
-- with ":".  The suffix records the state of the message.  Mail readers
-- may move files between directories and may change a file's suffix,
-- but the x.y.z part does not change.  See 
-- http://cr.yp.to/proto/maildir.html for details.

-- Grab the missing/unknown/ignored state, the directory name, the unique
-- portion and the suffix from "monotone automate inventory" output.
in_pat = "..([IMU]) %d+ %d+ ("
    .. maildir .. "/[^%c]*/)([^./:]+%.[^./:]+%.[^./:%c]+)([^%c]*)"

missing = {};
present = {};
mtout = io.popen("monotone automate inventory"):read("*a");
starts, ends, state, dir, unique, suffix = string.find(mtout, in_pat);
while starts do
    path = dir .. unique .. suffix;
    if state == "M" then
        missing[unique] = path
    elseif state == "U" or state == "I" then
        present[unique] = path;
    end
    starts, ends, state, dir, unique, suffix = string.find(mtout, in_pat, 
ends);
end

-- Assume that an unknown or ignored file name with the same unique part as a
-- missing file is the result of a file move, and that missing files that 
don't
-- share their unique part with an ignored or unknown file were deleted.
for unique, path in pairs(missing) do
    if present[unique] then
        os.execute("monotone rename " .. path .. " " .. present[unique]);
    else os.execute("monotone drop " .. path);
    end
end