Is there any reason you're not wanting to use the Rename procedure that's   
   part of the fpc system library?   
      
   www.freepascal.org/docs-html/rtl/system/rename.html   
      
   One problem with your code is that it would depend on a *nix style operating   
   system, and that the 'mv' command is available at your specified path.   
   Obviously that makes your code less portable. That might not matter, but if   
   it's potentially a concern it's worth noting.   
      
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