tagger

tagger is a program that monitors multiple separate project directory hierarchies and triggers a particular command when a file change is detected within these directory structures.

The main use case (and the one for which tagger was developed) is to facilitate the automatic and dynamic indexing of multiple software projects using an external program such as ctags. While the use of ctags is quite popular among emacs and vi users especially for dynamically-typed languages, there exist no tools for automating the re-indexing of multiple projects as their respectives files are added, removed and modified. tagger is developed in order to fill this gap.

Features

tagger has the following features:

• recursive monitoring of multiple project directories (using fsnotify)
• configuration over the program and arguments to run when a file change is detected (default is ctags -R -e)
• exclusion filters for ignoring project directories
• some support for secondary project directories (libraries) that are located outside the project directory tree (only ruby's rvm/bundler gemset paths supported at the moment)
• throttling of reindexing events; especially useful for actively developed projects
• a yaml configuration file for statically specifying which projects to monitor
• an http interface for adding/removing/listing projects dynamically at runtime

Known Issues

On MacOS there exists a known issue with filesystem monitoring using kqueue through the fsnotify library that produces a "too many open files" error. The solution is probably some adjustment of the relevant OS limit.

Installation

Linux binaries are available from the project's release page.

Usage

tagger -h will provide usage details for the program. A sample configuration yaml is also provided for reference for specifying the list of projects that tagger will start monitoring as well as indexer-specific details.

Development and Tests

First of all, make sure that you have a working go installation (this includes a valid $GOPATH). tagger can then be installed using:

$ go get -u github.com/kkentzo/tagger

The dep tool is also necessary for installing the program's dependencies:

$ go get -u github.com/golang/dep/cmd/dep
$ cd $GOPATH/src/github.com/kkentzo/tagger
$ dep ensure

The standard go tooling can be used to build the project and run the tests:

$ go build
$ go test ./... -v

Wish list

Some features that may be added in the project at some point:

• generalize a project's ancillary (secondary) indexer beyond ruby/rvm(for libraries that are located outside the project's directory tree)
• implement adaptive indexing by dynamically measuring indexing time per project and adjusting throttling accordingly

Contributing

Bug reports and pull requests are welcome on GitHub at the project's page. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

tagger is available as open source under the terms of the MIT License.