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  Case fold a given set of files either UP or down 
  
  USAGE : sh_casefold -dir <U or d> -files <list> -z
  
          <U or d> Case fold UP (U), down (d) 
          <list>   The names of file names to be casefolded (wild cards OK)
          <z> If you do NOT want to keep the upper case .Z compressed extention
  
  Example : sh_casefold -dir d -files *.98o
  
  Note: -files must be last argument on the command line.
        DEFAULT: Any .Z extension will remain upper case when folding down (-dir d)
  
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