检查一个字符串是否以使用正则表达式的数字开头

Question

如果一行以03:32:33（时间戳）之类的数字开头，我正在匹配时正在写入filebeat配置。我目前正在做 -

\d 

但它没有得到承认，有什么我应该做的。我不是特别好/有正则表达式的经验。帮助将不胜感激。

Answer 1

真正的问题是filebeatdoes not support \d。

替换\d通过[0-9]您的正则表达式将工作。

我建议你看看filebeat的Supported Patterns。

此外，请确定您使用的是^，它代表字符串的开头。

Answer 2

Regex: (^\d) 

1st Capturing group (^\d) 
    ^Match at the start of the string 
    \d match a digit [0-9] 

Answer 3

您可以使用：

^\d{2}:\d{2}:\d{2} 

字符^一行的开头匹配。

Answer 4

你可以使用这个表达式：

^([0-9]{2}:?){3}

---

DEMO

---

Assert position at the beginning of the string «^» 
Match the regex below and capture its match into backreference number 1 «([0-9]{2}:?){3}» 
    Exactly 3 times «{3}» 
     You repeated the capturing group itself. The group will capture only the last iteration. Put a capturing group around the repeated group to capture all iterations. «{3}» 
     Or, if you don’t want to capture anything, replace the capturing group with a non-capturing group to make your regex more efficient. 
    Match a single character in the range between “0” and “9” «[0-9]{2}» 
     Exactly 2 times «{2}» 
    Match the character “:” literally «:?» 
     Between zero and one times, as many times as possible, giving back as needed (greedy) «?»