peat @ 22289e267949 v0.1.0

#!/usr/bin/env python
# -*- coding: utf8 -*-

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                              # Repeat commands! #
                               ##################

import os, subprocess, sys, time
from optparse import OptionParser


interval = 1.0
command = 'true'
clear = True
paths = set()
verbose = True


def log(s):
    if verbose:
        print s

def die(s):
    sys.stderr.write('ERROR: ' + s + '\n')
    sys.exit(1)

def check(paths):
    cutoff = int(time.time() - interval)
    for p in paths:
        if os.stat(p).st_mtime >= cutoff:
            return True
    return False

def run():
    log("running: " + command)
    subprocess.call(command, shell=True)

def build_option_parser():
    p = OptionParser("usage: %prog [options] COMMAND\n\n"
                     "A list of paths to watch should be piped in on standard input.\n\n"
                     "COMMAND should be given as a single argument using a "
                     "shell string.\n\nFor example:\n\n"
                     "    find . | peat './test.sh'\n"
                     "    find . -name '*.py' | peat 'rm *.pyc'\n"
                     "    find . -name '*.py' -print0 | peat -0 'rm *.pyc'"
                     )

    # Main options
    p.add_option('-i', '--interval', default='1000',
                 help='interval between checks in milliseconds (default 1000)',
                 metavar='N')
    p.add_option('-c', '--clear', default=True,
                 action='store_true', dest='clear',
                 help='clear screen before runs (default)')
    p.add_option('-C', '--no-clear',
                 action='store_false', dest='clear',
                 help="don't clear screen before runs")
    p.add_option('-v', '--verbose', default=True,
                 action='store_true', dest='verbose',
                 help='show extra logging output (default)')
    p.add_option('-q', '--quiet',
                 action='store_false', dest='verbose',
                 help="don't show extra logging output")
    p.add_option('-w', '--whitespace', default=None,
                 action='store_const', dest='sep', const=None,
                 help="assume paths on stdin are separated by whitespace (default)")
    p.add_option('-n', '--newlines',
                 action='store_const', dest='sep', const='\n',
                 help="assume paths on stdin are separated by newlines")
    p.add_option('-s', '--spaces',
                 action='store_const', dest='sep', const=' ',
                 help="assume paths on stdin are separated by spaces")
    p.add_option('-0', '--zero',
                 action='store_const', dest='sep', const='\0',
                 help="assume paths on stdin are separated by null bytes")

    return p


def _main():
    log("Watching the following paths:")
    for p in paths:
        log("  " + p)
    log('')

    run()

    while True:
        time.sleep(interval)
        if check(paths):
            if clear:
                subprocess.check_call('clear')
            run()

def main():
    global interval, command, clear, paths, verbose

    (options, args) = build_option_parser().parse_args()

    if len(args) != 1:
        die("exactly one command must be given")

    command = args[0]
    interval = int(options.interval) / 1000.0
    clear = options.clear
    verbose = options.verbose
    sep = options.sep

    data = sys.stdin.read()
    if not sep:
        paths = data.split()
    else:
        paths = data.split(sep)

    paths = [p.rstrip('\n') for p in paths if p]
    paths = map(os.path.abspath, paths)
    paths = set(paths)

    for path in paths:
        if not os.path.exists(path):
            die('path to watch does not exist: ' + repr(path))

    if not paths:
        die("no paths to watch were given on standard input")

    _main()


if __name__ == '__main__':
    main()