给出（相对较长的）字符串：
string = "Checks for load balancers with listeners that do not use recommended security configurations for encrypted communication. AWS recommends using a secure protocol (HTTPS or SSL), up-to-date security policies, and ciphers and protocols that are secure.<br/>\nWhen you use a secure protocol for a front-end connection (client to load balancer), the requests are encrypted between your clients and the load balancer, which is more secure.<br/>\nElastic Load Balancing provides predefined security policies with ciphers and protocols that adhere to AWS security best practices. New versions of predefined policies are released as new configurations become available. <br/><br/>\n<b>Alert Criteria</b><br/>\nYellow: A load balancer has no listener that uses a secure protocol (HTTPS or SSL). <br/>\nYellow: A load balancer listener uses an outdated predefined SSL security policy. <br/>\nYellow: A load balancer listener uses a cipher or protocol that is not recommended. <br/>\nRed: A load balancer listener uses an insecure cipher or protocol.<br/><br/>\n<b>Recommended Action</b>\n<ul><li>If the traffic to your load balancer must be secure, use either the HTTPS or the SSL protocol for the front-end connection.</li>\n<li>Upgrade your load balancer to the latest version of the predefined SSL security policy.</li> \n<li>Use only the recommended ciphers and protocols.</li> </ul>\nFor more information, see <a target=\"_blank\" href=\"https://docs.aws.amazon.com/ElasticLoadBalancing/latest/DeveloperGuide/elb-listener-config.html\">Listener Configurations for Elastic Load Balancing</a>.<br/><br/>\n<b>Additional Resources</b><br/>\n<a target=\"_blank\" href=\"https://docs.aws.amazon.com/ElasticLoadBalancing/latest/DeveloperGuide/using-elb-listenerconfig-quickref.html\">Listener Configurations Quick Reference</a><br/>\n<a target=\"_blank\" href=\"https://docs.aws.amazon.com/ElasticLoadBalancing/latest/DeveloperGuide/ssl-config-update.html\">Update SSL Negotiation Configuration of Your Load Balancer</a><br/>\n<a target=\"_blank\" href=\"https://docs.aws.amazon.com/ElasticLoadBalancing/latest/DeveloperGuide/elb-ssl-security-policy.html\">SSL Negotiation Configurations for Elastic Load Balancing</a><br/>\n<a target=\"_blank\" href=\"https://docs.aws.amazon.com/ElasticLoadBalancing/latest/DeveloperGuide/elb-security-policy-table.html\">SSL Security Policy Table</a><br/>\n"
我想有一个方法，我将其中一个状态作为参数传递：
'Green' 'Yellow' 'Red' 这将返回一个完整的sencentes数组，跟随这个字符串（无论是多少次出现的字符串）。
def status_description(string, status)
# manipulate string and return status description(s)
end
使用上面的字符串，我希望
status_description(string, 'Yellow')
返回
[
'A load balancer has no listener that uses a secure protocol (HTTPS or SSL).',
'A load balancer listener uses an outdated predefined SSL security policy.',
'A load balancer listener uses a cipher or protocol that is not recommended.'
]
和
status_description(string, 'Red')
返回
['A load balancer listener uses an insecure cipher or protocol.']
字符串将始终具有相同的结构，这意味着状态描述始终遵循此部分：
\n<b>Alert Criteria</b><br/>
如果你可以让方法返回一个包含所有状态的哈希值（通常是前面提到的三个中的一部分或全部），那么它的'描述就完美了！类似的东西：
{
'Green' => ['some green desc']
'Yellow' => ['some yellow desc', 'another yellow desc'],
'Red' => ['some red desc']
}
我还需要获取'Recommended Action'的数组：
[
'If the traffic to your load balancer must be secure, use either the HTTPS or the SSL protocol for the front-end connection.',
'Upgrade your load balancer to the latest version of the predefined SSL security policy.',
'Use only the recommended ciphers and protocols.'
]
我对正则表达式几乎没有经验，在这种情况下可能不是那么简单。
非常感谢你的帮助！
答案 0 :(得分：7)
def status_description(str, color)
str.scan(/(?<=#{color}:\s).*?[.!?]/i)
end
status_description(string, "yellow")
#=> ["A load balancer has no listener that uses a secure protocol (HTTPS or SSL).",
# "A load balancer listener uses an outdated predefined SSL security policy.",
# "A load balancer listener uses a cipher or protocol that is not recommended."]
status_description(string, "green")
#=> []
status_description(string, "red")
#=> ["A load balancer listener uses an insecure cipher or protocol."]
有关
color = "yellow"
正则表达式
r = /
(?<= # begin a positive lookbehind
#{color} # match the value of the variable `color`
:\s # match a colon followed by whitespace
) # close positive lookbehind
.*? # match any number of any characters, lazily
[.!?] # match a character that terminates a sentence
/ix # case-indifference and free-spacing regex definition modes
#=> /
#=> (?<= # begin a positive lookbehind
# yellow # match the value of the variable `color`
# :\s # match a colon followed by whitespace
# ) # close positive lookbehind
# .*? # match any number of any characters, lazily
# [.!?] # match a character that terminates a sentence
# /ix
或者，根据要求，
["green", "yellow", "red"].each_with_object({}) { |c,h|
h[c] = status_description(string, c) }
#=> {"green" =>[],
# "yellow"=>[
# "A load balancer has no listener that uses a secure protocol (HTTPS or SSL).",
# "A load balancer listener uses an outdated predefined SSL security policy.",
# "A load balancer listener uses a cipher or protocol that is not recommended."
# ],
# "red"=>["A load balancer listener uses an insecure cipher or protocol."]
# }
您可以执行以下操作来提取包含“建议操作”的句子。 1
r0 = /
\n<b>Recommended\sAction<\/b>\n<ul><li> # match string
\K # discard everything matched so far
.+? # match any number of any character, lazily (?)
(?=<\/li>\s<\/ul>) # match string
/mx # multiline and free-spacing regex definition modes
r1 = /<\/li>\s*\n\s*<li>/ # match string
string[r0].split(r1)
#=> ["If the traffic to your load balancer must be secure, use either the \
# HTTPS or the SSL protocol for the front-end connection.",
# "Upgrade your load balancer to the latest version of the predefined \
# SSL security policy.",
# "Use only the recommended ciphers and protocols."]
请注意
string[r0]
#=> "If the traffic to your load balancer must be secure, use either \
# the HTTPS or the SSL protocol for the front-end connection.\
# </li>\n<li>Upgrade your load balancer to the latest version of the \
# predefined SSL security policy.</li> \n<li>Use only the recommended \
# ciphers and protocols."
1。在构建r0时，我将"Recommended Action"和"(?=<\/li> <\/ul>)"中的单个空格替换为\s。只有在以自由间隔模式（/x）定义正则表达式时才需要这样做，它忽略空格。此外，\n<b>Recommended\sAction<\/b>\n<ul><li>\K可以替换为正面的后视：(?<=\n<b>Recommended\sAction<\/b>\n<ul><li>)。最后，我格式化了返回字符串，因此无需水平滚动即可读取。
答案 1 :(得分：1)
你可以试试这个：
[^.]*Yellow:([^.]*).
使用方法中的变量更改黄色。 第1组将返回您想要的描述。
示例Ruby代码：
re = /[^.]*Yellow:([^.]*)./m
str = 'your large string goes here ................'
str.scan(re) do |match|
puts match.to_s
end
输出：
[" A load balancer has no listener that uses a secure protocol (HTTPS or SSL)"]
[" A load balancer listener uses an outdated predefined SSL security policy"]
[" A load balancer listener uses a cipher or protocol that is not recommended"]
答案 2 :(得分：1)
试试这些
颜色的正则表达式：
Yellow:\s*.*?\.
Red:\s*.*?\.
Green:\s*.*?\.
演示：https://regex101.com/r/IxoPB0/2
给定字符串中的推荐操作的正则表达式。
(?<=Recommended Action)<.*?li>(.*?)<\/li>.*?li>(.*?)<\/li>.*?li>(.*?)<\/li>
答案 3 :(得分：1)
由于此文本实际上是HTML，因此解析器（例如Nokogiri）比Regex更好。唯一的问题是这个HTML结构不是树，所以它使得解析起来有点困难。
String#split在这个例子中走了很长的路，完全不需要任何正则表达式。
代码首先将大字符串拆分为多个文本块（＆＃34;警报标准＆＃34;，＆＃34;推荐操作＆＃34;，...）。
对于＆＃34;警报标准＆＃34;阻止，它会在:周围分割每一行以获取颜色和文本，并创建一个数组哈希。
对于＆＃34;推荐操作＆＃34;，它只查找<li>和</li>之间的文字。
blocks = string.split("<br/><br/>\n").map do |block|
block.split('<br/>').map(&:strip)
end
### Analyzing criterias
criterias_block = blocks.find { |block| block.first.include?('Alert Criteria') }
criterias_hash = Hash.new { |h, k| h[k] = [] }
if criterias_block
header, *criterias = criterias_block
criterias.each_with_object(criterias_hash) do |line, hash|
color, criteria = line.split(': ')
hash[color] << criteria
end
end
pp criterias_hash
# {"Yellow"=>
# ["A load balancer has no listener that uses a secure protocol (HTTPS or SSL).",
# "A load balancer listener uses an outdated predefined SSL security policy.",
# "A load balancer listener uses a cipher or protocol that is not recommended."],
# "Red"=>["A load balancer listener uses an insecure cipher or protocol."]}
### Recommend actions
actions_block = blocks.find { |block| block.first.include?('Recommended Action') }
if actions_block
require 'nokogiri'
actions_html = Nokogiri::HTML(actions_block.first)
pp actions_html.css('li').map(&:text)
end
# ["If the traffic to your load balancer must be secure, use either the HTTPS or the SSL protocol for the front-end connection.",
# "Upgrade your load balancer to the latest version of the predefined SSL security policy.",
# "Use only the recommended ciphers and protocols."]