How do I convert a full path to a relative path using perl?

Question

I have the full path to a file and the full path to one of its parent directories in two variables in Perl program.

What is a safe way to calculate the relative path of the file relative to the parent directory. Needs to work on windows and unix.

eg

$filePath = "/full/path/to/my/file";
$parentPath = "/full";
$relativePath = ??? # should be "path/to/my/file"

Answer 1

Use File::Spec

They have a abs2rel function

my $relativePath = File::Spec->abs2rel ($filePath,  $parentPath);

Will work on both Windows and Linux

Answer 2

use Path::Class;
my $full = file( "/full/path/to/my/file" );
my $relative = $full->relative( "/full" );