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Lesson 8Perl e modifier
Objective 'e' modifier is placed at the end of the substitution expression.

Perl e modifier

The e modifier is used if you want the right-hand side of the substitution to be evaluated as code, instead of being treated as a string.
For example,
s/$(\w+)//e;

If there is a need to substitute the substring with a replacement string which is a regular expression to be evaluated, the 'e' modifier is used. The 'e' modifier is placed at the end of the substitution expression.
s/To_be_replaced/Regular_Expression/e;

That will replace anything that looks like a Perl scalar variable with the contents of that variable. This is extremely useful for embedding values in a text file.
Let us look at this example more closely:


Perl e-substitution Modifier