Regex: How to escape + sign?

[Vito Corleone]

Hi,

How can I escape + sign from regex? I want to change:
C++ to <b>C++</b>

Here is what I did:
#!/usr/bin/perl
$text = "C++";
$source = "Perl c++ c-- Java C-- C++";
$source =~ s#$text#<b>$text</b>#ig;
print $source . "\n";

[bk@wolverine bk]$ ./test.pl
Nested quantifiers in regex; marked by <-- HERE in m/C++ <-- HERE / at
../test.pl line 4.

How can I do that? Plese help.

--Vito

 

[Gunnar Hjalmarsson]

How can I escape + sign from regex?

------------^^^^^^

$source =~ s#$text#<b>$text</b>#ig;

Try:

$source =~ s#\Q$text#<b>$text</b>#ig;
-----------------^^

 

[Vito Corleone]

------------^^^^^^



Try:

$source =~ s#\Q$text#<b>$text</b>#ig;
-----------------^^

Wow, it works! Thanks Gunnar

--Vito

 

[J. Romano]

How can I escape + sign from regex?

Here is what I did:

$text = "C++";
$source = "Perl c++ c-- Java C-- C++";
$source =~ s#$text#<b>$text</b>#ig;

Vito,

Another way to do that is to change the line:

$text = "C++";

to:

$text = quotemeta("C++");

This will escape all non-alphanumeric characters so that the '+'
signs will match only to '+' signs if placed in a regular expression.
You can even print out $text after you set it to see what it looks
like -- it might help you understand what is happening.

-- Jean-Luc