在Perl正则表达式中转义特殊字符 [英] Escaping special characters in Perl regex

问题描述

我正在尝试匹配Perl中的正则表达式。我的代码如下所示：

  my $ source =Hello_ [version]; Goodbye_ [version]; 
我的$ pattern =Hello_ [version]; 
 if（$ source =〜m / $ pattern /）{
 printMatch found！ 
} 
  

问题出现在括号中，表示一个字符类（或者我读到的）当Perl尝试匹配正则表达式时，匹配结果将失败。我知道我可以用 \ [或 \] 摆脱括号，但这将需要另一个代码通过字符串搜索括号。有没有一种方法可以自动忽略括号，而不会单独转义它们？

快速注意：我不能添加反斜杠，因为这只是一个例子。在我的真实代码中， $ source 和 $ pattern 都来自Perl代码外（URIEncoded或从文件）。

解决方案

您正在使用错误的工具作为。

你没有图案！ $ pattern中没有正则表达式
个字符！

您有一个文字字符串。

索引（）用于处理文字字符串...

  my $ source =Hello_ [version]; Goodbye_ [version] ; 
我的$ pattern =Hello_ [version]; 
 if（index（$ source，$ pattern）！= -1）{
 printMatch found！; 
} 
  

I'm trying to match a regular expression in Perl. My code looks like the following:

my $source = "Hello_[version]; Goodbye_[version]";
my $pattern = "Hello_[version]";
if ($source =~ m/$pattern/) {
  print "Match found!"
}

The problem arises in that brackets indicate a character class (or so I read) when Perl tries to match the regex, and the match ends up failing. I know that I can escape the brackets with \[ or \], but that would require another block of code to go through the string and search for the brackets. Is there a way to have the brackets automatically ignored without escaping them individually?

Quick note: I can't just add the backslash, as this is just an example. In my real code, $source and $pattern are both coming from outside the Perl code (either URIEncoded or from a file).

解决方案

You are using the Wrong Tool for the job.

You do not have a pattern! There are NO regex characters in $pattern!

You have a literal string.

index() is for working with literal strings...

my $source = "Hello_[version]; Goodbye_[version]";
my $pattern = "Hello_[version]";
if ( index($source, $pattern) != -1 ) {
    print "Match found!";
}

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