You have a couple of bugs in your regex. You are missing the closing '/'.

You need an e flag to evaluate the substitution expression. However as it stands that gets messy because of the mixture of string litteral characters and characters that represent a calculation. No way Perl can disambiguate that!

I'd be inclined to do it like this:

use strict;
use warnings;

my $str = "<tag1>Complete</tag1><tag2>3386</tag2><tag3>77844</tag3><ta
+g4>11</tag4><tag5>30</tag5><tag6>4.7</tag6>";

if ($str =~ m|<tag1>Complete</tag1>|) {
     $str =~ s|(?<=<tag6>)(.*?)(?=</tag6>)|$1 * 100|e;
}

print $str;

[download]

Prints:

<tag1>Complete</tag1><tag2>3386</tag2><tag3>77844</tag3><tag4>11</tag4
+><tag5>30</tag5><tag6>470</tag6>

[download]

Note the use of strictures (use strict; use warnings;). The regex uses a look behind and a look ahead assertion to anchor the capture group so that the replaced text is only the number. The /e then gets the calculation done in the substitution.

DWIM is Perl's answer to Gödel

In reply to Re: Manipulating a string in a tagged file by GrandFather
in thread Manipulating a string in a tagged file by rsriram

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