Question

我不确定这是如何工作的/它意味着什么......

my ($value) = ($out =~ /currentvalue[^>]*>([^<]+)/);

基本上，这是CURL / PERL脚本的一部分，它会进入www.example.com，并在页面html中找到<{1}}
。

脚本的<span id="currentvalue"> GETS THIS VALUE </span>部分到底是做什么的？它是否定义了它寻找span id =＆＃34; ..＆＃34; ？

我在哪里可以了解有关[^＆gt;] *＆gt;（[^＆lt;] +）/）函数的更多信息？

Answer 1

/.../又名m/.../是匹配运算符。它检查其操作数（在=~的LHS上）是否与文字中的正则表达式匹配。运营商记录在perlop中。（转到“m / PATTERN /”。）正则表达式记录在perlre。

中

至于这里使用的正则表达式，

$ perl -MYAPE::Regex::Explain \
   -e'print YAPE::Regex::Explain->new($ARGV[0])->explain' \
      'currentvalue[^>]*>([^<]+)'
The regular expression:

(?-imsx:currentvalue[^>]*>([^<]+))

matches as follows:

NODE                     EXPLANATION
----------------------------------------------------------------------
(?-imsx:                 group, but do not capture (case-sensitive)
                         (with ^ and $ matching normally) (with . not
                         matching \n) (matching whitespace and #
                         normally):
----------------------------------------------------------------------
  currentvalue             'currentvalue'
----------------------------------------------------------------------
  [^>]*                    any character except: '>' (0 or more times
                           (matching the most amount possible))
----------------------------------------------------------------------
  >                        '>'
----------------------------------------------------------------------
  (                        group and capture to \1:
----------------------------------------------------------------------
    [^<]+                    any character except: '<' (1 or more
                             times (matching the most amount
                             possible))
----------------------------------------------------------------------
  )                        end of \1
----------------------------------------------------------------------
)                        end of grouping
----------------------------------------------------------------------

Answer 2

这是普通的Perilla regexp。见tutorial

  /              # Start of regexp  
  currentvalue   # Matches the string 'currentvalue'
  [^>]*          # Matches 0 or more characters which is not '>'
  >              # Matches >
  (              # Captures match enclosed in () to Perl built-in variable $1 
  [^<]+          # Matches 1 or more characters which  is not '<'  
  )              # End of group $1 
  /              # End of regexp

Perl / Curl脚本中的Perl正则表达式

2 个答案: