#!/usr/bin/perl -w

use strict;

sub checkit {
    my $file = shift;
    return (-e $file && -w _);  # the _ is a shortcut for checking on the same file instead of making another stat call
}

my $ret = checkit("/home/monk/hello");
if ($ret) { print "File exists with write perm\n" }
else { print "File does not exist or no write perm\n"; }