If I run it with perl -w (ActiveState 5.8), I get:

Unrecognized escape \g passed through at testfile line 3.
Unrecognized escape \g passed through at testfile line 3.
Unrecognized escape \g passed through at testfile line 3.
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You need to either use single quotes

  open (FOO,'>c:\gpp\gpp\gpp') ||die;
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or escape the backslashes

  open (FOO,">c:\\gpp\\gpp\\gpp") ||die;
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or use forward slashes:

  open (FOO,'>c:/gpp/gpp/gpp') ||die;
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