Just a few typo/editorial comments. On Thu, Sep 05, 2013 at 02:31:42PM +0200, Alan Schmitt wrote: > > * Synchronizing org files with Unison > > This describes how to synchronize org files using the > [[http://www.cis.upenn.edu/~bcpierce/unison/][Unison file synchronizer]], > as well as how to configure it to use an external tool to merge conflicting > edits. > > ** Prerequisites > > You should have Unison up and running. Binaries can be found > [[http://www.cis.upenn.edu/~bcpierce/unison/download.html][here]] and the > documentation is > [[http://www.cis.upenn.edu/~bcpierce/unison/download/releases/stable/unison-manual.html][here]]. > > ** Synchronization > > Unison is a file synchronizer, thus it may be used to synchronize org files. > To > configure Unison, on uses a /profile/ which states where the things to
on uses -> one uses > synchronize are as well as some options. Assuming I want to synchronize the > files in ~/Users/schmitta/dir1~ and ~/Users/schmitta/dir2~, the profile would > look like this > > #+BEGIN_EXAMPLE > root = /Users/schmitta/dir1 > root = /Users/schmitta/dir2 > #+END_EXAMPLE > > In most cases Unison will be used with a remote machine. The local machine is > called the /client/ and the remote one the /server/. For such remote > synchronization, the ~unison~ binary must be installed in the server as > well. The simplest way to connect to the machine is using ssh. One should > check > that unison can be found there by doing ~ssh user@remote unison -version~. If > ~unison~ cannot be found in the path, one may set the ~servercmd~ option as > indicated in the next example. > > (Please see the > [[http://www.cis.upenn.edu/~bcpierce/unison/download/releases/stable/unison-manual.html#roots][manual > section on roots]] for further details.) > > #+BEGIN_EXAMPLE > root = /Users/schmitta/dir1 > root = ssh://user@remote/relative/path/to/dir2 > > servercmd = /usr/bin/unison > #+END_EXAMPLE > > ** Merging > > As Unison works on the level of files, it will trigger a /conflict/ if both > files have changed since the last synchronization. In that case one can only > choose which file to keep, which is not satisfying. Unison offers the Maybe satisfactory is better than satisfying? > possibility to use external tools to merge the files. There is an > [[http://www.cis.upenn.edu/~bcpierce/unison/download/releases/stable/unison-manual.html#merge][extensive > manual section]] regarding this, we'll just describe how to use emacs and > ediff to > do it. > > For better merging, we will ask unison to keep the last synchronized version > of > every org file on the client; this way we can use ediff with ancestor. These > ~currentbackup~ files may live alongside the synchronized files (with names of > the form ~.bak.version.name~, which is configurable) or in a central location. > > Here is the modified configuration file. > > #+BEGIN_EXAMPLE > root = /Users/schmitta/dir1 > root = ssh://user@remote/relative/path/to/dir2 > > servercmd = /usr/bin/unison > > backupcurrent = Name *.org > backuplocation = local > maxbackups = 0 > > merge = Name *.org -> emacsclient -c --eval '(ediff-merge-files-with-ancestor > "CURRENT1" "CURRENT2" "CURRENTARCH" nil "NEW")' > > #+END_EXAMPLE > > The ~backupcurrent~ option tells unison to keep a backup of the last > synchronized version of ever file with an ~org~ extension. The location of the ever file -> every file > backup should be local (alongside the file). Finally, no other backup should > be > created. > > Next follows the merge command. For every org file in conflict, use the > command > that launches a new emacs frame calling the ediff with ancestor function. The > ~CURRENT1~, ~CURRENT2~, and ~CURRENTARCH~ strings are replaced with the file > from the first root, the file from the second root, and the last synchronized > version. The ~NEW~ file is where Unison expects the file to be saved (which > will > be done by the ediff session). > > Thus, when an org file has been modified on both hosts, an ediff session will > be > launched in a new frame. Closing the frame will make Unison commit the merge > (it > waits until the command has finished). > > If one does not want to use backups, it's possible to use the simpler ediff > (without ancestor) command as follows. > > #+BEGIN_EXAMPLE > root = /Users/schmitta/dir1 > root = ssh://user@remote/relative/path/to/dir2 > > servercmd = /usr/bin/unison > > merge = Name *.org -> emacsclient -c --eval '(ediff-merge-files "CURRENT1" > "CURRENT2" nil "NEW")' > > #+END_EXAMPLE This a very clear and complete write-up. Thanks a lot Alan! :) -- Suvayu Open source is the future. It sets us free.
