download.py

#! /usr/bin/env python
# vim: set fileencoding=utf-8

"""
download softwares
"""

import os, sys

p = os.path

if p.dirname(p.abspath(sys.argv[0])) != os.getcwd():
    print "Usage: ./download.py"
    sys.exit(1)

wget = os.popen('which wget').read() # 返回值里包含"\n"
if not len(wget):
    print "* wget not found."
    sys.exit(2)

wget = wget.replace('\n', '')

# urls to download softwares
urls = (
        'http://www.python.org/ftp/python/3.0.1/Python-3.0.1.tar.bz2',
        'http://monkey.org/~provos/libevent-1.4.9-stable.tar.gz',
        'http://sysoev.ru/nginx/nginx-0.6.35.tar.gz'
       )

to_download = filter(lambda x: not os.path.exists(x.split('/')[-1:][0]), urls)

if len(to_download):
    for cmd in map(lambda x: wget + ' ' + x, to_download):
        os.system(cmd)
else:
    print "* nothing to download."