Question

我的条件可能是我的字符串：

test23 @ testbee：在/ var /蜂/

或

testbee：/var/bee/test.html

我需要在这里提取三个字符串：test23（如果可用），testbee和test.html

所以，在Perl中，

($user, $sys, $file) = ($source =~ /(\S*?)\@?(\S+?):?[^:]*?([^\/]+)$/);

for 1. this give，$ user =，$ sys = test @ testbee，$ file = test.html for 2. give，$ user =，$ sys = test，$ file = test.html

有没有办法，我可以使用一个表达式来获取用户'test'（如果它存在），如果不存在则没有。

Answer 1

更易于维护的解决方案：

select T.number, max(T.MOST_FREQUENT) max_val, W.MOST_FREQUENT, W.Type
  from (

  SELECT *, SUM(quantity) AS MOST_FREQUENT
       FROM datas
       WHERE date_status=1
       GROUP BY number,type
       ORDER BY SUM(quantity) DESC LIMIT 200 ) T 
  INNER JOIN (
  SELECT *, SUM(quantity) AS MOST_FREQUENT
           FROM datas
           WHERE date_status=1
           GROUP BY number,type
           ORDER BY SUM(quantity) DESC LIMIT 200
  ) W ON T.number = W.number 
  group by T.number, , W.MOST_FREQUENT, W.Type
  ORDER BY  concat(lpad(max(T.MOST_FREQUENT), 10, '0'), T.number)  DESC
           , (concat(max(T.MOST_FREQUENT, T.number))= concat(W.MOST_FREQUENT, T.number)) DESC
           ,  W.MOST_FREQUENT
           , W.Type

Answer 2

此处总是将可选部分与第1组匹配，有时$1或$3将为空：

(?:(\w+)@)?(\w+):(?:\/\w+){2}\/((?:\w|\.)*)

演示：regex101

如果您想跳过更多子目录，请将{2}替换为*。

可选字符匹配正则表达式

2 个答案: