You should really test your code before posting. All the \ dissapear from $str - use non-interpolating ' rather than " to fix that.

There is a missing / in the split regex and an extra ) following it.

Even after fixing those errors, when the code is run a "Use of uninitialized value in split" warning is issued and incorrect output is generated:

\source\test\test.c@@main\com\etc c:\temp\source\test\test1.c@@main\co
+m\test c:\temp\source\test\test3\test2.c@@main\com\etc\test
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