#!/usr/bin/perl
use strict;
use warnings;
use File::Spec;

my $somepath = "/var/log/../../home/poletti/../../etc/passwd";

print "starting path: [$somepath]\n";
print "wanted path: [/etc/passwd]";
print "canonpath: [", File::Spec->canonpath($somepath), "]\n";
print "rel2abs: [", File::Spec->rel2abs($somepath), "]\n";
print "abs2rel: [", File::Spec->rel2abs($somepath, "/"), "]\n";
my @portions = File::Spec->splitpath($somepath);
print "splitpath + catpath: [", File::Spec->catpath(@portions), "]\n";
__END__

__output__
starting path: [/var/log/../../home/poletti/../../etc/passwd]
wanted path: [/etc/passwd]
canonpath: [/var/log/../../home/poletti/../../etc/passwd]
rel2abs: [/var/log/../../home/poletti/../../etc/passwd]
abs2rel: [/var/log/../../home/poletti/../../etc/passwd]
splitpath + catpath: [/var/log/../../home/poletti/../../etc/passwd]