需要一种从文件中获取信息并跳过信息是否在另一个文件中的方法

Question

我有一个名为 skip.txt 的文件，其中包含以下信息：

stackoverflow.com 
github.com 
www.sa-k.net 
yoursearch.me 
search1.speedbit.com 
duckfm.net
search.clearch.org 
webcache.googleusercontent.com

我还有一个名为 information.txt 的文件，其中包含以下信息：

http://search.clearch.org/?a=web&q=Viewcat_h.php%3Fidcategory%3D%20%3Cstrong%3ESite%3C%2Fstrong%3E%20.pl%20
https://moodle.org/mod/forum/discuss.php?d=246409
http://webcache.googleusercontent.com/search?q=cache:oqPwN7FtDWgJ
http://www.aquariumist.com.ua/spr.php?id=7
http://search.clearch.org/?a%3Dweb%26q%3DViewcat_h.php%253Fidcategory%253D%2520%253Cstrong%253ESite%253C%252Fstrong%253E%2520.pl%2520%2Binurl:viewCat_h.php?idCategory%3D&hl=en&gbv=1&ct=clnk
http://www.astbury.leeds.ac.uk/research/spr.php
http://www.media4play.li/s/spr+php+id.html
http://v.virscan.org/SPR/PHP.ID.html
http://search.clearch.org/?a=images&q=Viewcat_h.php%3Fidcategory%3D+
http://search.clearch.org/?a=web&q=Inurl%20Viewcat_h.php%3Fidcategory%3D%20Site%20Clinsp=%3Fpvaid%3D97f2b2aa136c4af0936453a19d9ab1b2%26fcoid%3D302363
http://webcache.googleusercontent.com/search?q=cache:5qNE1JBqUeIJ
http://search.clearch.org/?a%3Dweb%26q%3DInurl%2520Viewcat_h.php%253Fidcategory%253D%2520Site%2520Cl%26insp%3D%253Fpvaid%253D97f2b2aa136c4af0936453a19d9ab1b2%2526fcoid%253D302363%2Binurl:viewCat_h.php?idCategory%3D&hl=en&gbv=1&ct=clnk

我想要一种方法来获取此信息并移动到next url，有没有一种方法可以从skip.txt 文件中读取，如果information.txt 文件包含该skip.txt 文件中的任何内容，请移动到文件中的下一个 url？

预期输出：

http://www.astbury.leeds.ac.uk/research/spr.php
http://www.media4play.li/s/spr+php+id.html
http://v.virscan.org/SPR/PHP.ID.html
https://moodle.org/mod/forum/discuss.php?d=246409
http://www.aquariumist.com.ua/spr.php?id=7

我做了一些研究，发现了 grep 函数，但这需要一个复杂的正则表达式，我不是很好。所以如果你能帮助我找到一种方法来跳过skip.txt 中的信息，或者帮助我使用一个很棒的正则表达式！提前谢谢你。

Answer 1

假设您将跳过文件读入变量skip，将信息文件读入变量info_file。那么

skip_arr = skip.split("\n").map(&:strip)
  #=> ["stackoverflow.com", "github.com", "www.sa-k.net", "yoursearch.me",
  #    "search1.speedbit.com", "duckfm.net", "search.clearch.org",
  #    "webcache.googleusercontent.com"]

.map(&:strip)（您可以将其视为.map { |s| s.strip }）使用String#strip 删除围绕skip.split("\n") 生成的数组元素的所有空格。这可能没有必要，但预防措施无害。

info_arr = info.split("\n")
  #=> ["http://search.clearch.org/?a=web&q=Viewcat_h...,
  #    "https://moodle.org/mod/forum/discuss.php?d=246409",
  #    "http://webcache.googleusercontent.com/search?q=cache:oqPwN7FtDWgJ",
  #    "http://www.aquariumist.com.ua/spr.php?id=7",
  #    "http://search.clearch.org/?a%3Dweb%26q%3DViewcat_h.php...,
  #    "http://www.astbury.leeds.ac.uk/research/spr.php",
  #    "http://www.media4play.li/s/spr+php+id.html",
  #    "http://v.virscan.org/SPR/PHP.ID.html",
  #    "http://search.clearch.org/?a=images&q=Viewcat_h.php%3Fidcategory%3D+",
  #    "http://search.clearch.org/?a=web&q=Inurl%20Viewcat_h.php...,
  #    "http://webcache.googleusercontent.com/search?q=cache:5qNE1JBqUeIJ",
  #    "http://search.clearch.org/?a%3Dweb%26q%3DInurl%2520Viewcat_h.php...]

接下来我们定义一个正则表达式。

r = / 
    (?<=\/\/)  # match two forward slashes in a positive lookbehind
    #{ Regexp.union(skip_arr) } # match any element of skip_arr
    (?=\/)     # match a forward slash in a positive lookahead
    /x         # free-spacing regex definition mode
#=> / 
    (?<=\/\/)  # match two forward slashes in a positive lookbehind
    (?-mix:stackoverflow\.com|github\.com|www\.sa\-k\.net|yoursearch\.me|
      search1\.speedbit\.com|duckfm\.net|search\.clearch\.org|
      webcache\.googleusercontent\.com) # match any element of skip_arr
    (?=\/)     # match a forward slash in a positive lookahead
    /x 

最后，使用Array#reject 方法删除info.arr 中匹配此“正则表达式”的元素：

info_arr.reject { |s| s =~ r }
  #=> ["https://moodle.org/mod/forum/discuss.php?d=246409",
  #    "http://www.aquariumist.com.ua/spr.php?id=7", 
  #    "http://www.astbury.leeds.ac.uk/research/spr.php",
  #    "http://www.media4play.li/s/spr+php+id.html",
  #    "http://v.virscan.org/SPR/PHP.ID.html"]