This is a common problem for people with a PHP background attempting to code in Perl.

The philosophy in PHP was to pack as much functionality into the core as possible. Given that it was designed pretty much exclusively as a web application language, there is plenty of support for HTML / HTTP, etc type functionality such as the htmlentities() function. This worked pretty well for PHP, since it meant once it was installed on a webserver, you had most of the tools you needed to write basic web apps.

As Perl is a much more general purpose language, it doesn't make sense to include such functionality in the core. But that doesn't mean it doesn't exist. There is a huge amount of this functionality (and much much more) on CPAN.

However, many PHP programmers might search the core docs of Perl, find that an equivelent function isn't there, and assume it must not exist. Once you get used to looking at CPAN for a solution, you start to realise the full potential of Perl.