Python:将/etc/services 文件导入字典

Question

所以我必须创建一个 python 脚本来导入 /etc/services 文件并将其写入字典。

目标是端口/协议(protocol)将成为键，服务成为值。我希望能够打印输入关键信息的字典并查看服务返回结果:

print(yourdictionaryname["22/tcp"])
ssh

这个脚本是我能得到的最远的。我在网上找到它并且效果很好，但它旨在仅显示未使用的端口。似乎无法修改它来做我需要的:

# set the file name depending on the operating system
if sys.platform == 'win32':
file = r'C:\WINDOWS\system32\drivers\etc\services'
else:
file = '/etc/services'

# Create an empty dictionary
ports = dict()

# Iterate through the file, one line at a time
for line in open(file):

# Ignore lines starting with '#' and those containing only whitespace
if line[0:1] != '#' and not line.isspace():

   # Extract the second field (seperated by \s+)
   pp = line.split(None, 1)[1]

   # Extract the port number from port/protocol
   port = pp.split ('/', 1)[0]

   # Convert to int, then store as a dictionary key
   port = int(port)
   ports[port] = None

   # Give up after port 200
   if port > 200: break

# Print any port numbers not present as a dictionary key
for num in xrange(1,201):
if not num in ports:
    print "Unused port", num

Answer 1

根据您要完成的任务，socket模块可能足以满足您的需求，其 getservbyname 和 getservbyport 功能:

>>> socket.getservbyport(22)
'ssh'
>>> socket.getservbyport(22, 'udp')
'ssh'
>>> socket.getservbyport(22, 'tcp')
'ssh'
>>> socket.getservbyname('http')
80
>>> socket.getservbyname('http', 'tcp')
80
>>> socket.getservbyname('http', 'udp')
80

如果您真的需要字典，您可以使用 getservbyport 遍历 range(1, 65536)。