text: import glob
  import os
  import re
  import string
  
  
  import vim
  
  
  def catFile(filename):
      """ assigns a local variable retval to the contents of a file """
      try:
          fp = open(filename)
          lines = fp.read()
          fp.close()
      except FileNotFoundError:
          lines = ''
  
      # escape double quotes and backslashes before quoting the string so
      # everything passes throught.
      vim.command("""let retval = "%s" """ % re.sub(r'"|\\', r'\\\g<0>', lines))
      return lines
  
  
  def isPresentInFile(regexp, filename):
      """ check if regexp is present in the file """
      try:
          fp = open(filename)
          fcontents = fp.read()
          fp.close()
          if re.search(regexp, fcontents):
              vim.command('let retval = 1')
              return 1
          else:
              vim.command('let retval = 0')
              return None
      except FileNotFoundError:
          vim.command('let retval = 0')
          return None
  
  
  def deleteFile(filepattern):
      """ deletes a file if present
  
         If the file does not exist, check if its a filepattern rather than a
         filename. If its a pattern, then deletes all files matching the pattern.
      """
      try:
          if os.path.isfile(filepattern):
              os.remove(filepattern)
          else:
              if glob.glob(filepattern):
                  for filename in glob.glob(filepattern):
                      os.remove(filename)
              else:
                  vim.command('let retval = -1')
      except:
          vim.command('let retval = -1')
  
  # vim:ff=unix:noet:ts=4:sw=4:nowrap
  