code: def perl_dash_pie(oldstr, newstr, dry_run=None):
      r"""Use perl to replace the oldstr with the newstr.
  
      Examples
      --------
  
      # To replace all occurrences of 'import numpy as N' with 'import numpy as np'
      from nipy.utils import perlpie
      perlpie.perl_dash_pie(r'import\s+numpy\s+as\s+N', 'import numpy as np')
      grind | xargs perl -pi -e 's/import\s+numpy\s+as\s+N/import numpy as np/g'
  
      """
  
      if dry_run:
          cmd = f"grind | xargs perl -p -e 's/{oldstr}/{newstr}/g'"
      else:
          cmd = f"grind | xargs perl -pi -e 's/{oldstr}/{newstr}/g'"
      print(cmd)
  
      try:
          subprocess.check_call(cmd, shell=True)
      except subprocess.CalledProcessError as err:
          msg = f"""
          Error while executing perl_dash_pie command:
          {cmd}
          Error:
          {str(err)}
          """
          raise Exception(msg)
  
imports: import subprocess
  from optparse import OptionParser
label_desc: Use image node_id 2 for calling a global function with example usage: perl_dash_pie(oldstr, newstr, dry_run) without return types