my $verbose = 1;
my $r_cat = 'ssh %s cat "%s" |'; # host, file

sub r_open {
    my ($spec) = @_;
    my ($host,$file) = split /:/, $spec,2;
    my $cmd = sprintf $r_cat, $host, $file;
    print "Opening [$cmd]\n" if $verbose;
    open my $fh, $cmd
        or die "Couldn't open remote file: $cmd: $!/$?";
    $fh
};

my $fh = r_open('user@host:some/file');
while (<$fh>) {
    chomp;
    print "I read line '$_'\n";
};