I second this.

use File::Spec::Functions;
my $path = catfile("xyzz", "qwen", "defs", "asd");
# $path is now "xyzz/qwen/defs/asd" on most systems,
# but on Windows it'll have backslashes instead
# and I think on old MacOS Classic systems it would
# have colons or something.  Don't ask about VMS.
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