Perl正则表达式

Question

I'm reading some code that involves regular expression and having some trouble. 我正在阅读一些涉及正则表达式的代码，遇到了一些麻烦。

Can someone please explain it and give an example of text it would parse? 有人可以解释一下，并举例说明它可以解析的文本吗？

if(/\|\s*STUFF(\d+)\s*\|\s*STUFF(\d+)/) 
{
        $a = $1;
        $b = $2;
}

Answer 1

One string it matches against is |STUFF1|STUFF2 . 与之匹配的一个字符串是|STUFF1|STUFF2 。

YAPE::Regex::Explain YAPE :: Regex :::说明

(?-imsx:\|\s*STUFF(\d+)\s*\|\s*STUFF(\d+))

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):
----------------------------------------------------------------------
  \|                       '|'
----------------------------------------------------------------------
  \s*                      whitespace (\n, \r, \t, \f, and " ") (0 or
                           more times (matching the most amount
                           possible))
----------------------------------------------------------------------
  STUFF                    'STUFF'
----------------------------------------------------------------------
  (                        group and capture to \1:
----------------------------------------------------------------------
    \d+                      digits (0-9) (1 or more times (matching
                             the most amount possible))
----------------------------------------------------------------------
  )                        end of \1
----------------------------------------------------------------------
  \s*                      whitespace (\n, \r, \t, \f, and " ") (0 or
                           more times (matching the most amount
                           possible))
----------------------------------------------------------------------
  \|                       '|'
----------------------------------------------------------------------
  \s*                      whitespace (\n, \r, \t, \f, and " ") (0 or
                           more times (matching the most amount
                           possible))
----------------------------------------------------------------------
  STUFF                    'STUFF'
----------------------------------------------------------------------
  (                        group and capture to \2:
----------------------------------------------------------------------
    \d+                      digits (0-9) (1 or more times (matching
                             the most amount possible))
----------------------------------------------------------------------
  )                        end of \2
----------------------------------------------------------------------
)                        end of grouping
----------------------------------------------------------------------

Answer 2

\|\s*STUFF(\d+)\s*\|\s*STUFF(\d+)

\\| look for a literal pipe character | 寻找文字管道字符| . 。

\\s* look for any number (zero or more) whitespace characters. \\s*寻找任何数字（零个或多个）空白字符。

STUFF look for the string STUFF STUFF查找字符串STUFF

(\\d+) look for any number of digits (one or more), and save them to $1 . (\\d+)查找任意位数（一个或多个），并将其保存到$1 。

\\s* look for any number of whitespace characters (zero or more) \\s*查找任意数量的空格字符（零个或多个）

then repeat once, and save the next digit sequence in $2 . 然后重复一次，并将下一个数字序列保存在$2 。

If the regex matches, we know that $1 and $2 must be defined (ie they have a value). 如果正则表达式匹配，我们知道必须定义$1和$2 （即它们具有值）。

In that case, we assign $1 to the variable $a and $2 to $b . 在这种情况下，我们将$1分配给变量$a ，将$2分配给$b 。

As no explicit string to match against is provided, the $_ variable is implicitly used. 由于没有提供要匹配的显式字符串，因此将隐式使用$_变量。

Example text: 示例文字：

foo bar |STUFF123|STUFF456 baz bar foo

and 和

foo |

  STUFF0 
|STUFF1234567890bar

Perl正则表达式

问题描述

2 个解决方案

解决方案1
2 已采纳 2012-09-21 01:59:01

解决方案2
2 2012-09-21 01:59:27

Perl正则表达式

问题描述

2 个解决方案

解决方案1 2 已采纳 2012-09-21 01:59:01

解决方案2 2 2012-09-21 01:59:27

解决方案1
2 已采纳 2012-09-21 01:59:01

解决方案2
2 2012-09-21 01:59:27