Try File::Spec, namely its rel2abs() function:
It's not a function, it's a class method. If you want a function — and I can understand that, try File::Spec::Functions (also standard) instead. 
use File::Spec::Functions qw(rel2abs);

$abs_path = rel2abs( $path );

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In reply to Re^2: How to get a file's full path? by bart
in thread How to get a file's full path? by Bog

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