opun.py - open with default app and keep file associations

opun.py

#!/usr/bin/env python

import optparse
import os
import sys

# Change this to whatever app you want to open by default.
DEFAULT_APP = "Coda"

def main(args):
    parser = optparse.OptionParser()
    
    # These are just wrappers for the OS X "open" command and will all be passed when it is run.
    parser.add_option('-a', '--app', metavar="APPLICATION", default=DEFAULT_APP, dest="app",
                    help="Opens with the specified application. Default is %s" % DEFAULT_APP,)
    parser.add_option('-w', '--wait', action="store_true", default=False, dest='wait',
                    help="Blocks until the used application is closed (even if they were already running).")
    parser.add_option('-n', '--new', default=False, action="store_true", dest="new",
                    help="Open a new instance of the application even if one is already running")
    parser.add_option('-g', '--background', default=False, action="store_true", dest="background",
                    help="Does not bring not bring the application to the foreground.")
                    
    (opts, args) = parser.parse_args(args)

    switches = ""
    switches += 'W' if opts.wait else ""
    switches += 'n' if opts.new else ""
    switches += 'g' if opts.background else ""
    
    # If we have switches add the tack.
    switches = "-" + switches if switches else ""

    # Create files if any filenames passed in do not exits.
    [open(f, 'w') for f in args if not os.path.isfile(f)]
    
    # Run OS X "open" command.
    cmd = "open %s -a %s %s" % (switches, opts.app, " ".join(args))
    os.system(cmd)
    
if __name__ == "__main__":
    main(sys.argv[1:])