code: def catFiles(filesToCat, catFile):
      
      if len(filesToCat) == 0: #We must handle this case or the cat call will hang waiting for input
          open(catFile, 'w').close()
          return
      maxCat = 25
      system("cat %s > %s" % (" ".join(filesToCat[:maxCat]), catFile))
      filesToCat = filesToCat[maxCat:]
      while len(filesToCat) > 0:
          system("cat %s >> %s" % (" ".join(filesToCat[:maxCat]), catFile))
          filesToCat = filesToCat[maxCat:]
docs: Cats a bunch of files into one file. Ensures a no more than maxCat files
      are concatenated at each step.