Python - プロセスとシステムサービス: 限界を超える(os module, fork method, プロセスID, 親プロセス, 子プロセス)

Programming Python
( O'Reilly Media)
Mark Lutz(著)

開発環境

• OS X Mavericks - Apple(OS)
• Emacs (CUI)、BBEdit - Bare Bones Software, Inc. (GUI) (Text Editor)
• Python 3.4 (プログラミング言語)

Head First C ―頭とからだで覚えるCの基本(David Griffiths (著)、Dawn Griffiths (著) 中田 秀基(監訳)(翻訳)、木下 哲也 (翻訳)、オライリージャパン)の9章(プロセスとシステムサービス: 限界を超える)、エクササイズ(p.417)をpythonで考えてみる。

エクササイズ(p.417)

コード(BBEdit, Emacs)

newshound.py

#!/usr/bin/env python3
#-*- coding: utf-8 -*-

import os
import sys

feeds = ["http://rss.cnn.com/rss/edition.rss",
         "http://rss.cnn.com/rss/edition_world.rss",
         "http://rss.cnn.com/rss/edition_africa.rss",
         "http://rss.cnn.com/rss/edition_americas.rss",
         "http://rss.cnn.com/rss/edition_asia.rss",
         "http://rss.cnn.com/rss/edition_europe.rss",
         "http://rss.cnn.com/rss/edition_meast.rss",
         "http://rss.cnn.com/rss/edition_us.rss"]
phrase = sys.argv[1]

for feed in feeds:
    env = dict(RSS_FEED=feed)
    try:
        pid = os.fork()
    except Exception as err:
        print(type(err), err)
    else:
        if pid != 0:
            try:
                os.execle('/usr/bin/python', '/usr/bin/python', 'rssgossip.py',
                          phrase, env)
            except Exception as err:
                print(type(err), err)

入出力結果(Terminal, IPython)

$ cp newshound.py  old_newshound.py
$ ./old_newshound.py 'world'
World's weirdest plane turns 20
Zakaria: Is the world going nuts?
World's most frustrating objects
World's strangest-looking plane turns 20
Are these the world's sexiest accents?
Can the world stop Ebola?
World's 15 best rivers for travelers
$ ./newshound.py 'world'
Building the world's tallest tower
Post-9/11 world of threats
World's biggest record collection
World-class Caribbean carnival
And the world's busiest airport is ...
The world's sexiest accents
Spreading ethio-jazz to the world
The world of Somalian literature
Can this school save the world?
CNN.com - World
CNN.com - World
What's the world's sexiest accent?
World's weirdest plane turns 20
Zakaria: Is the world going nuts?
World's most frustrating objects
World's strangest-looking plane turns 20
Are these the world's sexiest accents?
Can the world stop Ebola?
World's 15 best rivers for travelers
$