perl 正则表达式中的字符串变量含有中括号

wpeng18

请教一下各位，百思不得其解。
perl 正则表达式中的字符串变量含有中括号，结果就无法匹配成功。
$a="abc[0]";
$b="bc[0]";
$a=~/$b/;
这样的匹配怎么也不成功，如果b没有中括号就可以，请问b中带有中括号，我该怎么匹配呢。谢谢哥哥帮助。

ludio333

$a=~/\Q$b\E/;

kk861123

或者用quotemeta

xiyoulaoyuanjia

In Perl regular expressions, you can surround a subexpression with \Q and \E to indicate that you want that subexpression to be matched as a literal string even if there are metacharacters in there. You also have the quotemeta function that inserts exactly the right number of backslashes in a string so that if you subsequently interpolate that string into a regular expression, it will be matched literally, no matter what its contents were!

1. #!/usr/bin/perl -w
   
2. use strict;
   
3. use warnings;
   
4. 
   
5. 
   
6. my $a="abc[0]";
   
7. my $b="bc[0]";
   
8. my $c=quotemeta($b); # $c eq ‘bc\[0\]’;
   
9. if($a=~/$c/){print "match\n";} # results in “match” being printed.
   
10. if($a=~/\Q$b\E/){print "match\n";} # results in “match” being printed.
    
11. 
    

复制代码

kyotouni

4楼的太好太详细了 mark之