Depends on your system. 
use File::Spec;
print File::Spec->canonpath("foo/../bar/../baz/")."\n";

[download]
\baz

[download]

On system without symlinks, canonpath collapses x/../y (although not always correctly, as shown above).

Update: Technically, NTFS does have symlinks, but most software act as if they don't exist, including File::Spec.

In reply to Re^3: Collapsing paths by ikegami
in thread Collapsing paths by rvosa

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