自动下载并合并Hosts文件，在Fedora23上测试通过

README.md

自动下载并合并Hosts文件

hosts.py [--download] [--apply] [--addhosts url] [--pid]

• --download 下载Hosts文件（合并至hosts.tmp）
• --apply 应用至系统（/etc/hosts）
• --addhosts url 添加URL到HOSTS源列表（hosts.json）
• --pid 显示pid

默认携带的HOSTS源：

• https://coding.net/u/Elaine_ni/p/hosts/git/raw/master/hosts.txt
• https://raw.githubusercontent.com/lack006/Android-Hosts-L/master/hosts_files/2016_hosts/RE_full
• https://raw.githubusercontent.com/racaljk/hosts/master/hosts
• https://raw.githubusercontent.com/sy618/hosts/master/ADFQ

还有一个要强调的： 没有自动备份！没有自动备份！没有自动备份！

ChangeLog:

• Revision 5
• • 修复readall方法部分平台没有的问题
• Revision 4
• • 添加ChangLog和提示
• Revision 3
• • 添加README.md
• Revision 2
• • 修改注解
• Revision 1
• • 首次发布

hosts.py

#!python3
#coding=utf-8

"""
Download and apply hosts.

@anthor: thislight
"""

import os
import sys
import json
import os.path as path
import urllib.request as request


cmdline = {}


SYS_HOSTS_PATH = "/etc/hosts"


TMP_HOSTS_PATH = "./hosts.tmp"


arg_map = {
    "--addlist" : "add_list",
    "--apply" : "apply",
    "--download" : "download",
    "--addhosts" : "add_hosts",
    "--removechange" : "remove_change",
    "--pid" : "show_pid",
    "-d" : "download",
    "-r" : "remove_change",
    "-a" : "apply"
    }


CONFIG_PATH = "./hosts.json"


DEFAULT_HOSTS = [
    "https://coding.net/u/Elaine_ni/p/hosts/git/raw/master/hosts.txt",
    "https://raw.githubusercontent.com/lack006/Android-Hosts-L/master/hosts_files/2016_hosts/RE_full",
    "https://raw.githubusercontent.com/racaljk/hosts/master/hosts",
    "https://raw.githubusercontent.com/sy618/hosts/master/ADFQ"
    ]

global config
config = []


def is_arg_op(s):
    return s.startswith("--") or s.startswith("-")


def get_true_op(s):
    return arg_map[s]


def parse_cmdline():
    """
    Parse cmd line arg.
    """
    ops = [ v for v in sys.argv if (is_arg_op(v) and (v in arg_map)) ]
    for v in ops:
        index = sys.argv.index(v)
        if len(sys.argv)>index+1:
            tmp = sys.argv[index+1]
        else:
            tmp = 'True'
        if not is_arg_op(tmp):
            cmdline[get_true_op(v)] = tmp
        else:
            cmdline[get_true_op(v)] = True


def when_error(e,*arg):
    print("A Error happened!\n",e,"\n",repr(arg))


def get_file(url):
    """
    download file.
    @param url: file url
    """
    try:
        with request.urlopen(url) as f:
            return f.read()
    except request.HTTPError as e:
        when_error(e,url)
    except request.URLError as e:
        when_error(e,url)
    except ValueError as e:
        when_error(e,url)


def _save_config(l):
    json.dump(l,open(CONFIG_PATH,mode="w"))


def save_config():
    """
    Save config to disk.
    """
    _save_config(config)


def read_config():
    """
    Read config to disk.
    """
    return json.load(open(CONFIG_PATH,mode="r"))


def load_config():
    """
    Load config
    """
    global config
    config = read_config()


def check_has_file():
    """
    Check config file exists.
    """
    if not path.exists(CONFIG_PATH):
        _save_config(DEFAULT_HOSTS)
        config = DEFAULT_HOSTS


def join_hosts(*args):
    """
    @return: str
    """
    return ''.join(args)


def write_hosts(s):
    """
    Write to system hosts.
    Need root permission.
    """
    with open(SYS_HOSTS_PATH,mode="wb") as f:
        f.write(s)


def onload():
    """
    Call when start
    """
    parse_cmdline()
    check_has_file()
    load_config()


def onexit():
    """
    Call when exit.
    """
    save_config()


def add_list():
    pass


def apply():
    with open(TMP_HOSTS_PATH,mode="rb") as f:
        write_hosts(f.read())
    print("Apply to %s finished." % SYS_HOSTS_PATH)


def download():
    print("Start download..")
    with open(TMP_HOSTS_PATH,mode="wb") as f:
        for v in config:
            print("Downloading file %s from %s." % (path.split(v)[-1],v))
            f.write(get_file(v))
            f.write(b"\n")
            print("Downloaded file %s from %s." % (path.split(v)[-1],v))
            print("-"*6)
    print("Finished")


def add_hosts():
    config.append(cmdline.get("add_hosts"))
    print("Added %s" % cmdline.get("add_hosts"))


def remove_change():
    write_hosts("")
    print("Removed.")


def show_pid():
    print("Pid : %s" % os.getpid())


def main():
    for k in cmdline: print("%s -> %s" % (k,cmdline[k]))
    for k in cmdline:
        eval("%s()" % k,globals())


if __name__ == "__main__":
    onload()
    main()
    onexit()