peat

peat repeats commands.

It's kind of like Kicker except:

• It doesn't use inotify or OS X FSEvents, so it'll run anywhere.
• It doesn't require external libraries, so it'll run anywhere with Python.
• It won't eat your CPU (unless you try to watch too much).
• It takes paths to watch on standard input so you can use something like find(1) or friendly-find to specify what to watch.

Installation

Get the peat script on your machine and into your $PATH somehow. Copy and paste it, curl it, or clone the repository. Make sure it's executable. That's it.

Usage

Generate a list of files you want to watch for changes, separated by whitespace. echo(1), find(1) or friendly-find are good for this:

$ ffind '.*.py$'
./foo.py
./bar.py

$ echo *.py
foo.py bar.py

Now pipe that to peat, and specify the command you want to run whenever one of those files changes:

$ ffind '.*.py$' | peat 'echo "A file changed!"'

Use Ctrl-C to stop.

The command to run needs to be specified as a single argument to peat. You can do this with a shell string as seen above. Using a single-quoted string like this will preserve wildcards and such:

$ ffind '.*.py$' | peat 'rm *.pyc'

This will delete all .pyc files in the current directory when a Python file is modified. Google around for "shell quoting" if you don't understand what's happening here.

Dynamic File Listing

If you want to build the file list fresh each time (so that peat will pick up newly created files without having to restart it) you can use the --dynamic option.

Instead of piping in the list of files to watch, you'll pipe in a command that peat will run to generate the list before every check. For example:

$ ffind ".markdown$"
./foo.markdown
./bar/baz.markdown

$ echo 'ffind ".markdown$"'
ffind ".markdown$"

$ echo 'ffind ".markdown$"' | peat --dynamic 'echo "A file changed!"'

If your command contains quotes you'll need to make sure they get passed into peat properly. For example, the following will not work:

$ echo "find . -name '*.markdown'" | peat --dynamic ...

The problem is that the shell will expand the * in the double-quoted string before it ever gets to peat. Google around and learn about shell quoting if you don't understand. This can be tricky. You've been warned.

Full Usage

Here's the full usage:

Usage: peat [options] COMMAND

COMMAND should be given as a single argument using a shell string.

A list of paths to watch should be piped in on standard input.

For example:

    find . | peat './test.sh'
    find . -name '*.py' | peat 'rm *.pyc'
    find . -name '*.py' -print0 | peat -0 'rm *.pyc'

If --dynamic is given, a command to generate the list should be piped in
on standard input instead.  It will be used to generate the list of files
to check before each run.

This command must be quoted properly, and this can be tricky.  Make sure
you know what you're doing.

For example:

    echo find . | peat --dynamic './test.sh'
    echo find . -name '*.py' | peat --dynamic 'rm *.pyc'


Options:
  -h, --help            show this help message and exit
  -i N, --interval=N    interval between checks in milliseconds
  -I, --smart-interval  determine the interval based on number of files
                        watched (default)
  -d, --dynamic         take a command on standard input to generate the list
                        of files to watch
  -D, --no-dynamic      take a list of files to watch on standard in (default)
  -c, --clear           clear screen before runs (default)
  -C, --no-clear        don't clear screen before runs
  -v, --verbose         show extra logging output (default)
  -q, --quiet           don't show extra logging output
  -w, --whitespace      assume paths on stdin are separated by whitespace
                        (default)
  -n, --newlines        assume paths on stdin are separated by newlines
  -s, --spaces          assume paths on stdin are separated by spaces
  -0, --zero            assume paths on stdin are separated by null bytes

License

Copyright 2012 Steve Losh and contributors.

Licensed under version 3 of the GPL.

Remember that you can use GPL'ed software through their command line interfaces without any license-related restrictions. peat's command line interface is the only stable one, so it's the only one you should ever be using anyway. The license doesn't affect you unless you're:

• Trying to copy the code and release a non-GPL'ed version of peat.
• Trying to use it as a Python module from other Python code (for your own sanity I urge you to not do this) and release the result under a non-GPL license.