syncdir.scm

An rclone wrapper for two-way synchronization.

Syncs files in a local and remote directory, saving a time stamp for each file into a file .sync-times in the local directory. If both the local and the remote file have been modified relatively to the saved time stamp, syncdir.scm will run a merge command.

Config file

There is a config file $XDG_CONFIG_PATH/syncdir.scm (if $XDG_CONFIG_PATH isn't set, it defaults to "~/.config"). It's an association list. The following keys are meaningful:

• paths: an association list of named paths. For example, an entry might look like this: (foo "/path/to/local/foo" "remote:foo"). Currently, it's only possible to synchronize named path pairs.
• ignore-globs: a list of globs with which to match filenames. All files whose name matches at least one of this globs are skipped by syncdir.scm. Example: (ignore-globs "*~" "*.tmp" ".*.sw?").
• merge-cmd: merge command in the command syntax with keys a, b and output as the 2 files being merged and the output file respectively. Envioronment variable SYNCDIR_MERGE overrides this config option, however, it isn't read as a list -- instead it is put into a template like this:

`(,(getenv "SYNCDIR_MERGE") a b output)

If neither is specified, value of VISUAL or EDITOR (defaulting to "vi") is used, with the 3 file names appended (like SYNCDIR_MERGE). This key can also be overridden for specific files

For example, a config file may look like this (I don't use KDiff3, but that's what its command line looks like according to documentation):

((paths
  (org "~/org" "remote:org"))
 (ignore-globs "*~" ".#*#")
 (merge-cmd
  "kdiff3" a b "-o" output))

Leading tilde is supported in filenames (both "~/..." and "~user/...").

Path overrides

All keys can be overridden in specific paths (except paths itself). ignore-globs list is appended, while merge-cmd is replaced completely. To override/extend a particular key, add a pair (key . new-value) to the path list:

(path-name "/local/path" "remote:path" (ignore-globs "more"))

Glob overrides

Some keys (currently only merge-cmd) can be overridden for a set of file names specified as globs. Such override specifications can be nested. Example:

(paths
  (foo "/local/foo" "remote:foo"
    (merge-cmd "merge-in-foo" a b output)
    ("*.org"
      (merge-cmd "merge-org-files-in-foo" a b output)
      ("project-*"
        (merge-cmd "merge-projects-org-files-in-foo" a b output)))))

Glob syntax

Asterisk (*, any number of characters), question mark (?, any single character), bracketed expressions ([...] or [!...] for complement, ranges supported: [a-z], - may appear without special meaning as first or last character in the set, ] only as first one), alternatives ({A,B,C}, at least one subexpression should match) and escaping special characters (for instance, \[ matches character [ itself) are supported in globs.

Command syntax

Commands are lists of strings and symbols. When the command is run, symbols (keys) are replaced with their meanings (for instance, in a merge command, a, b and output are replaced with two merged file names and the output file name respectively) and the list is executed as a command. It is not passed to the shell but instead executed 'directly': the program is searched on $PATH and the arguments are passed with no modifications (see documentation for Guile's system* procedure).

Dummy mode

There is a dummy mode in which files aren't copied and merges aren't run. It can be used to quickly check what's going to be synchronized. Currently the only way to enable dummy mode is to specify an environment variable SYNCDIR_DUMMY.

Command line

The following command line options are available:

• -h: display a help message.
• -v, -q, -Q: verbose, quiet and silent modes respectively. In silent mode, no messages are output to stdout (exceptions are still displayed to stderr). In quiet mode, only merge messages are displayed (they announce which files are going to be merged). In normal mode (default), copies are also announced. In verbose mode, exception backtraces are also displayed.
• -n: dummy mode.

These options also have long names; run syncdir.scm -h to view them.