Sunflower.py

#!/usr/bin/env python
#
#	Sunflower File Manager
#	http://sunflower-fm.org
#
#	Copyright (c) 2011. by Mladen (MeanEYE) Mijatov
#
#   This program is free software: you can redistribute it and/or modify
#   it under the terms of the GNU General Public License as published by
#   the Free Software Foundation, either version 3 of the License, or
#   (at your option) any later version.
#
#   This program is distributed in the hope that it will be useful,
#   but WITHOUT ANY WARRANTY; without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#   GNU General Public License for more details.
#
#   You should have received a copy of the GNU General Public License
#   along with this program.  If not, see <http://www.gnu.org/licenses/>.

import os
import sys
import subprocess

default_paths = os.pathsep.join(('/bin', '/usr/bin', '/usr/local/bin'))
search_paths = os.environ.get('PATH', default_paths).split(os.pathsep)
interpreter_list = ('python2.9', 'python2.8', 'python2.7', 'python2.6')
application_file = os.path.join(os.path.dirname(sys.argv[0]), 'application', 'main.py')

def _can_execute(path):
	"""Check if specified path can be executed"""
	return os.path.exists(path) and os.access(path, os.X_OK)

def _check_interpreter(interpreter):
	"""Check path for existing interpreters"""
	result = None

	for path in search_paths:
		full_path = os.path.join(path, interpreter)

		if _can_execute(full_path):
			# interpreter was found in specified directory
			result = full_path
			break

	return result

def _get_interpreters():
	"""Return available interpreters"""
	result = []

	# check every interpreter in the list
	for item in interpreter_list:
		full_path = _check_interpreter(item)

		if full_path is not None:
			result.append(full_path)

	return result


# get 2.x interpreter
interpreters = _get_interpreters()

if len(interpreters) > 0:
	code = 2

	# try with all interpreters
	for interpreter in interpreters:
		params = [os.path.abspath(sys.argv[0]), application_file]
		params.extend(sys.argv[1:])

		# execute interpreted
		process = subprocess.Popen(params, executable=interpreter)
		process.wait()

		if process.returncode == 0:
			# if interpreter manages to run
			# we don't need to execute others
			break

		else:
			# print interpreter error
			print("Failed running with {0}".format(os.path.basename(interpreter)))

	sys.exit(code)

else:
	# no valid interpreters found, notify user
	print("No valid Python 2.x interpreter was found!")
	sys.exit(2)