spy: A compact file system watcher for Mac OS X

[ bsd3, development, program ] [ Propose Tags ]

Spy can be used to watch for file changes and to either report the modified files or run a command if files change. It can be used to trigger compilation, to run tests or start a deployment.

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Versions 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 0.10, 0.12, 0.13, 0.14
Dependencies base (>=3 && <5), cmdargs (>=0.10), directory (>=1.1), filemanip (>=, filepath (>=1.3), hfsevents (>=0.1.3), json (>=0.7), process (>=1.1) [details]
License BSD-3-Clause
Author Stefan Saasen
Maintainer stefan@saasen.me
Category Apple, Development
Home page https://bitbucket.org/ssaasen/spy
Bug tracker https://bitbucket.org/ssaasen/spy/issues
Source repo head: git clone git@bitbucket.org:ssaasen/spy.git
Uploaded by StefanSaasen at Tue Dec 18 11:58:05 UTC 2012
Distributions NixOS:0.14
Executables spy
Downloads 2988 total (19 in the last 30 days)
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Status Docs not available [build log]
All reported builds failed as of 2016-12-22 [all 6 reports]
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Maintainer's Corner

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Readme for spy-0.4

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Spy is a compact file system watcher for Mac OS X using the File System Events API via hfsevents.


Spy expects a single argument, the directory or a single file to watch. Spy currently supports two different modes: watch and run mode.

Watch mode

In output mode Spy will print the path to a modified file to STDOUT (followed by a newline) whenever a file modification (new file added, file modified, file deleted) occurs.

$> spy watch .

Because watch is the default mode you can omit the watch command if you want:

$> spy .

It's possible to watch a single file (this obviously only shows changes to that particular file):

$> spy /path/to/file

The default format is the full path to the modified file followed by a newline. To make it easier to parse the output, the --format=json changes the output to be printed formatted as a JSON object (again followed by a newline).

$> spy watch --format=json .
{"path": "path/to/modified/file", "flags": ["ItemModified"], "id": 123143234}

For directories the following options apply:

An optional second argument can be used to filter the files in the given directory using a glob pattern:

$> spy watch /path/to/directory "*.md"

Run mode

In run mode Spy will execute a given command whenever a file modification occurs without printing modifications to stdout. The command will be executed with the path to the modified file as the last argument.

$> spy run "./run-build.sh"

In the example above the shell script run-build.sh would be executed with the path to the modified file as the first argument.

If the command to be executed does not expect any (additional) arguments the --notify-only flag can be used. This will cause spy to execute the command without passing the path as an argument:

$> spy run --notify-only "rake test" .


Spy only works on Mac OS X >= 10.7 (Lion and above)!

Binary distribution

The binary distribution contains a 64bit binary compiled for Mac OS X > 10.7.

Download the tarball and run "make install" to copy the binary and the man page into the correct target directories:

$> curl -OL https://bitbucket.org/ssaasen/spy/downloads/spy-osx-x86_64-v0.4.tar.gz
$> tar xfz spy-osx-x86_64-v0.4.tar.gz
$> cd spy
$> make install

The user manual should now be available via man spy and the spy executable should be on your $PATH.

Source distribution

To install spy from source you need the Haskell platform installed and cabal-install available on your $PATH:

$> cabal install --only-dependencies
$> cabal configure
$> cabal build

This will create the spy binary in the ./dist/build/spy directory.

To copy the spy binary to the cabal bin directory (which should be available on your PATH) use:

$> cabal copy