Security Layer in PIR for PL/Parrot

Parrot

.namespace ["PLParrot"]

.sub open :method
    .param pmc args :slurpy
    print "Attempt to open "
    $S1 = args[0]
    say $S1
.end

.sub copy :method
    .param pmc from
    .param pmc to
    print from
    print "="
    say to
.end

.sub rename :method
    .param pmc from
    .param pmc to
    print "Attempt to copy file "
    print from
    print " to "
    say to
.end

.namespace []
.sub _ :load :init :anon
    load_bytecode 'P6object.pbc'

    .local pmc p6meta, interp, classes, classid
    p6meta = get_root_global ["parrot"], "P6metaclass"
    p6meta.'new_class'('PLParrot')

    interp = getinterp
    classes = interp[0]
    classid = classes['PLParrot']
    set classes['FileHandle'], classid
    set classes['File'], classid
.end

.sub main :main
    .local pmc fh, file
    new fh, 'FileHandle'
    fh.'open'("/etc/passwd")

    new file, 'File'
    file.'rename'('foo','bar')
.end


The above code prints:

Attempt to open /etc/passwd
Attempt to copy file foo to bar