It's a little redundant to see if the string begins with a ~ and then remove it, when s/^~// will only return true if it replaced anything.

Also, it might be nice to fallback to the home directory returned by getpwuid just in case $ENV{'HOME'} isn't set ...

use File::Spec;

my $filename = '~/public_html/';

if ( $filename =~ s<^~([^/]*)/></> ) {
    my $homedir = $1  ? (getpwnam($1))[7] # specified user
      : $ENV{'HOME'} || (getpwuid($<))[7] # ourselves
    or die "Where's your home?\n";


    $filename = File::Spec->catfile($homedir, $filename);
}
[download]

Update: Fixed to account for jeffenstein's observation.

    --k.