NAME
    App::Inotify::Hookable - blocking command-line interface to inotify

SYNOPSIS
    Watch a directory, tell us when things change in it:

        inotify-hookable --watch-directories /tmp/watch-this

    Watch a git tree, some configs, and a repository of static assets,
    restart the webserver or compress those assets if anything changes:

        inotify-hookable \
            --watch-directories /etc/uwsgi \
            --watch-directories /git_tree/central \
            --watch-directories /etc/app-config \
            --watch-directories /git_tree/static_assets \
            --on-modify-path-command "^(/etc/uwsgi|/git_tree/central|/etc/app-config)=sudo /etc/init.d/uwsgi restart" \
            --on-modify-path-command "^/git_tree/static_assets=(cd /git_tree/static_assets && compress_static_assets)"

    Or watch specific files:

        inotify-hookable \
            --watch-files /var/www/cgi-bin/mod_perl_handler \
            --on-modify-command "apachectl restart"

DESCRIPTION
    This simple command-line program is my replacement for the functionality
    offered by Plack's Filesys::Notify::Simple. I found that on very large
    git trees Plack would spend an inordinate amount watching the filesystem
    for changes.

    This program uses Linux::Inotify2, so the kernel will notify it
    instantly when something changes (actually it's so fast that we have to
    work around how fast it sends us events).

    The result is that you can run this e.g. in a screen session and have it
    watch your development environment, and your webserver will have begun
    restarting before your finger leaves the *save* button.

    vim and emacs temporary files are ignored by default (see
    "--ignore-paths".) so you can edit your files without your server
    restarting unnecessarily.

    Currently the command-line interface for this is the only one that
    really makes sense, this module is entirely blocking (although it could
    probably run in another process via POE or something). Patches welcome.

OPTIONS
  "-w" or "--watch-directories"
    Specify this to watch a directory, you can give this however many times
    you like to watch lots of directories.

  "-f" or "--watch-files"
    Watch a file, specify multiple times for multiple files. You can watch
    files and directories in the same command.

  "-r" or "--recursive"
    If you supply this any directory you give will be recursively watched.
    This is on by default.

  "-c" or "--on-modify-command"
    A command that will be run when something is modified.

  "-C" or "--on-modify-path-command"
    A key-value pair where the key is a regex that'll be matched against a
    modified path, and the value is a command that'll be run. See the
    "SYNOPSIS" for an example.

    Useful for e.g. restarting a webserver if you modify directory A but
    compressing some static assets if you modify directory B.

  "-t" or "--buffer-time"
    Linux will send you inotify events really fast, so fast that if you run
    something like:

        touch foo bar

    You might get an event for foo in one batch, followed by an event for
    bar later on.

    To deal with this we enter a loop when we start getting events and sleep
    for a default of 100 microseconds, as long as we keep getting events we
    keep sleeping for 100 microseconds, but as soon as we haven't received
    anything new we fire off our event handlers.

  "-i" or "--ignore-paths"
    Regexes for files/directories to ignore events for. By default this is
    set to regexes for vim and emacs temporary files, "qr{\..*sw.\z}" and
    "qr{\.\#[^/]+\z}" respectively.

    The regexes match after any "/" in the path or the beginning of the
    string.

  "-d" or "--debug"
    Spew out some verbose debug output while running.

ACKNOWLEDGMENT
    This module was originally developed at and for Booking.com. With
    approval from Booking.com, this module was generalized and put on CPAN,
    for which the authors would like to express their gratitude.

AUTHOR
    Ævar Arnfjörð Bjarmason <avar@cpan.org>

