use strict;
my $str = '<category name="Content Server Categories:FOLDER:test category">
<attribute name="test attribuut"><![CDATA[test]]></attribute>
<attribute name="test attribuut1"><![CDATA[test1]]></attribute>
</category>
<category name="Content Server Categories:FOLDER1:FOLDER2:test category">
<attribute name="test attribuut"><![CDATA[test]]></attribute>
<attribute name="test attribuut1"><![CDATA[test1]]></attribute>
</category>
<category name="Content Server Categories:FOLDER NAME:test category">
<attribute name="test attribuut"><![CDATA[test]]></attribute>
<attribute name="test attribuut1"><![CDATA[test1]]></attribute>
</category>
<category name="Content Server Categories:FOLDER NAME: FOLDER NAME1:test category">
<attribute name="test attribuut"><![CDATA[test]]></attribute>
<attribute name="test attribuut1"><![CDATA[test1]]></attribute>
</category>
<category name="Content Server Categories:FOLDER:test category name">
<attribute name="test attribuut"><![CDATA[test]]></attribute>
<attribute name="test attribuut1"><![CDATA[test1]]></attribute>
</category>';
my $regex = qr`(?s)<(category) name="Content Server Categories:(.+?)">(.+?)</(category)>`mp;
my $subst = '<$1-$2 name="Content Server Categories:$2">$3</$1-$2>';
my $result = $str =~ s`$regex`$subst`rg;
print "The result of the substitution is' $result\n";
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Perl, please visit: http://perldoc.perl.org/perlre.html