Ruby：将转义字符串写入YAML
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require 'yaml' test = "I'm a b&d string" File.open('test.yaml', 'w') do |out| out.write(test.to_yaml) end ……输出……
--- this is a b&d string
我怎样才能输出它
--- 'this is a b&d string'
???
如果要在YAML中存储转义字符串， #inspect在将其转换为YAML之前使用#inspect对其进行#inspect ：
irb> require 'yaml' => true irb> str = %{This string's a little complicated, but it "does the job" (man, I hate scare quotes)} => "This string's a little complicated, but it \"does the job\" (man, I hate scare quotes)" irb> puts str This string's a little complicated, but it "does the job" (man, I hate scare quotes) => nil irb> puts str.inspect "This string's a little complicated, but it \"does the job\" (man, I hate scare quotes)" => nil irb> puts str.to_yaml --- This string's a little complicated, but it "does the job" (man, I hate scare quotes) => nil irb> puts str.inspect.to_yaml --- "\"This string's a little complicated, but it \\\"does the job\\\" (man, I hate scare quotes)\"" => nil
除非必须，YAML不引用字符串。 它引用了字符串，如果它们包含了它会在未加引号存储的情况下会丢失的东西 – 比如周围的引号字符或尾随或前导空格：
irb> puts (str + " ").to_yaml --- "This string's a little complicated, but it \"does the job\" (man, I hate scare quotes) " => nil irb> puts %{"#{str}"}.to_yaml --- "\"This string's a little complicated, but it \"does the job\" (man, I hate scare quotes)\"" => nil irb> puts (" " + str).to_yaml --- " This string's a little complicated, but it \"does the job\" (man, I hate scare quotes)" => nil
但是，作为YAML消费者，字符串是否引用对您来说无关紧要。 你永远不应该自己解析YAML文本 – 把它留给库。 如果你需要在YAML文件中引用字符串，那对我来说闻起来很糟糕。
你的字符串中是否包含“＆”并不重要，YAML会保留字符串：
irb> test = "I'm a b&d string" => "I'm a b&d string" irb> YAML::load(YAML::dump(test)) => "I'm a b&d string" irb> YAML::load(YAML::dump(test)) == test => true
根据YAML 1.2规范 ，JSON文档是有效的YAML文档。
此修订的主要目标是使YAML符合JSON作为官方子集。
因此，有效的JSON字符串是有效的YAML字符串。
require 'json' 'my string'.to_json # => produces a valid YAML string
这对于富含ERB语法的YAML文件非常有用，其中string.to_yaml在许多情况下不起作用。
例：
# openvpn.yml.erb openvpn: cert: <%= ENV.fetch('OPENVPN_CERT').to_json %> key: <%= ENV.fetch('OPENVPN_KEY').to_json %>