Regular Expressions

Variable interpolation

You may write variable names inside a regular expression, and they will be interpolated into their values.

Example

  $name = "Danny";
  if ($text =~ /$name is here/) {  }

# same as:
# if ($text =~ /Danny is here/) {  }

Meta-characters

As we have seen before, the following characters have special meaning inside regular expressions. If you want to use them literally, add a backslash before them.

\ | ( ) [ { ^ $ * + ? .

Example

To match "5*(12+7)=45. right?" write: 
$text =~ /5\*\(12\+7\)=45\. right\?/;

Note:

Closing HTML tags require a backlash inside regular expressions: 
$html =~ /<H1>.*<\/H1>/;

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