MONiter & EXecute

monex.py

#!/usr/bin/env python
# encoding: utf-8

"""
MONitor & EXecute
Yong-Yeol Ahn (http://yongyeol.com/)

This script monitors multiple files and executes the given command when
any of those files is changed.

Modified by Jim Bagrow, 2011-02-17
"""

import sys, os, time, signal
from glob import glob
from optparse import OptionParser
from itertools import izip
import tty
from select import select

ssw = sys.stdout.write
ssf = sys.stdout.flush

def end_handler(signum, frame):
    print "\n===  Terminating monex...  Have a nice day!  ==="
    sys.exit(0)

class TerminalFile:
    """Adapted from http://code.activestate.com/recipes/203830/"""
    def __init__(self,infile):
        if not infile.isatty():
            raise Exception()
        self.file = infile
        
        # prepare for getch:
        self.save_attr=tty.tcgetattr(self.file)
        newattr=self.save_attr[:]
        newattr[3] &= ~tty.ECHO & ~tty.ICANON
        tty.tcsetattr(self.file, tty.TCSANOW, newattr)
    
    def __del__(self):
        # restoring stdin:
        import tty  # required this import here
        tty.tcsetattr(self.file, tty.TCSADRAIN, self.save_attr)
    
    def getch(self):
        if select([self.file],[],[],0)[0]:
            return self.file.read(1)
        return ""


def do(command):
    ssw( "[%s] Running `%s'..." % (time.strftime('%X %Y-%m-%d'),command) ); ssf()
    os.system("%s" % (command))
    ssw( ' done\n' ); ssf()

def get_filelist(args):
    files = set()
    for arg in args:
        files |= set(glob(arg))
    return sorted(files)

def parse_command(cmd,files):
    """check if special % mode is in use"""
    if len(files) == 1 and cmd.strip()[-1] == "%":
        cmd = cmd.replace("%", files[0])
    return cmd

def pretty_files_str(files):
    files_str = ", ".join(files)
    if len(files_str) > 75:
        return "%s [...] %s" % (files[0],files[-1])
    return files_str

def clear_line():
    ssw( "\r" + " "*100 + "\r" ); ssf()

def print_paused(paused, files_str):
    if paused:
        ssw( "===  Paused  ===" ); ssf()
    else:
        ssw( "===  Watching %s  ===" % files_str ); ssf()
    

if __name__ == '__main__':
    usage = 'usage: %prog -c "command" file1 file2 ...'
    parser = OptionParser(usage=usage)
    parser.add_option("-c", "--command", dest='command', help="command to be executed")
    
    (options, args) = parser.parse_args()
    if not options.command:
        parser.error('-c option is needed.')
    sleep_time = 0.2
    
    signal.signal(signal.SIGINT, end_handler)
    print "MONEX: press p to pause/unpause, r/f to force the command, and q to quit..."
    s = TerminalFile( sys.stdin )
    paused = False
    
    
    files     = get_filelist(args)
    files_str = pretty_files_str(files)
    command   = parse_command( options.command.strip('"'), files )
    
    old_timestamps = [ -1 for x in files]
    while True:

        char = s.getch()
        if char == 'q':
            end_handler(0,0)
        elif char == 'p':
            clear_line()
            paused = (not paused)
            print_paused(paused, files_str)
        elif char == 'r' or char == 'f':
            clear_line()
            do(command)
            print_paused(paused, files_str)
        
        if not paused:
            curr_timestamps = [os.stat(x).st_mtime for x in files]
            if any(curr != old for curr, old in izip(curr_timestamps, old_timestamps)):
                clear_line()
                do(command)
                ssw( "===  Watching %s  ===" % files_str ); ssf()
                old_timestamps = curr_timestamps
        
        time.sleep( sleep_time )

Now supports keypresses to pause/unpause/quit