text: #! /usr/local/bin/python
  
  # NOTE: the above "/usr/local/bin/python" is NOT a mistake.  It is
  # intentionally NOT "/usr/bin/env python".  On many systems
  # (e.g. Solaris), /usr/local/bin is not in $PATH as passed to CGI
  # scripts, and /usr/local/bin is the default directory where Python is
  # installed, so /usr/bin/env would be unable to find python.  Granted,
  # binary installations by Linux vendors often install Python in
  # /usr/bin.  So let those vendors patch cgi.py to match their choice
  # of installation.
  
  """Support module for CGI (Common Gateway Interface) scripts.
  
  This module defines a number of utilities for use by CGI scripts
  written in Python.
  """
  
  # History
  # -------
  #
  # Michael McLay started this module.  Steve Majewski changed the
  # interface to SvFormContentDict and FormContentDict.  The multipart
  # parsing was inspired by code submitted by Andreas Paepcke.  Guido van
  # Rossum rewrote, reformatted and documented the module and is currently
  # responsible for its maintenance.
  #
  
  __version__ = "2.6"
  
  
  # Imports
  # =======
  
  from io import StringIO, BytesIO, TextIOWrapper
  from collections.abc import Mapping
  import sys
  import os
  import urllib.parse
  from email.parser import FeedParser
  from email.message import Message
  import html
  import locale
  import tempfile
  
  __all__ = ["MiniFieldStorage", "FieldStorage", "parse", "parse_multipart",
             "parse_header", "test", "print_exception", "print_environ",
             "print_form", "print_directory", "print_arguments",
             "print_environ_usage"]
  
  # Logging support
  # ===============
  
  logfile = ""            # Filename to log to, if not empty
  logfp = None            # File object to log to, if not None
  
  def initlog(*allargs):
      """Write a log message, if there is a log file.
  
      Even though this function is called initlog(), you should always
      use log(); log is a variable that is set either to initlog
      (initially), to dolog (once the log file has been opened), or to
      nolog (when logging is disabled).
  
      The first argument is a format string; the remaining arguments (if
      any) are arguments to the % operator, so e.g.
          log("%s: %s", "a", "b")
      will write "a: b" to the log file, followed by a newline.
  
      If the global logfp is not None, it should be a file object to
      which log data is written.
  
      If the global logfp is None, the global logfile may be a string
      giving a filename to open, in append mode.  This file should be
      world writable!!!  If the file can't be opened, logging is
      silently disabled (since there is no safe place where we could
      send an error message).
  
      """
      global log, logfile, logfp
      if logfile and not logfp:
          try:
              logfp = open(logfile, "a")
          except OSError:
              pass
      if not logfp:
          log = nolog
      else:
          log = dolog
      log(*allargs)
  
  def dolog(fmt, *args):
      """Write a log message to the log file.  See initlog() for docs."""
      logfp.write(fmt%args + "\n")
  
  def nolog(*allargs):
      """Dummy function, assigned to log when logging is disabled."""
      pass
  
  def closelog():
      """Close the log file."""
      global log, logfile, logfp
      logfile = ''
      if logfp:
          logfp.close()
          logfp = None
      log = initlog
  
  log = initlog           # The current logging function
  
  
  # Parsing functions
  # =================
  
  # Maximum input we will accept when REQUEST_METHOD is POST
  # 0 ==> unlimited input
  maxlen = 0
  
  def parse(fp=None, environ=os.environ, keep_blank_values=0,
            strict_parsing=0, separator='&'):
      """Parse a query in the environment or from a file (default stdin)
  
          Arguments, all optional:
  
          fp              : file pointer; default: sys.stdin.buffer
  
          environ         : environment dictionary; default: os.environ
  
          keep_blank_values: flag indicating whether blank values in
              percent-encoded forms should be treated as blank strings.
              A true value indicates that blanks should be retained as
              blank strings.  The default false value indicates that
              blank values are to be ignored and treated as if they were
              not included.
  
          strict_parsing: flag indicating what to do with parsing errors.
              If false (the default), errors are silently ignored.
              If true, errors raise a ValueError exception.
  
          separator: str. The symbol to use for separating the query arguments.
              Defaults to &.
      """
      if fp is None:
          fp = sys.stdin
  
      # field keys and values (except for files) are returned as strings
      # an encoding is required to decode the bytes read from self.fp
      if hasattr(fp,'encoding'):
          encoding = fp.encoding
      else:
          encoding = 'latin-1'
  
      # fp.read() must return bytes
      if isinstance(fp, TextIOWrapper):
          fp = fp.buffer
  
      if not 'REQUEST_METHOD' in environ:
          environ['REQUEST_METHOD'] = 'GET'       # For testing stand-alone
      if environ['REQUEST_METHOD'] == 'POST':
          ctype, pdict = parse_header(environ['CONTENT_TYPE'])
          if ctype == 'multipart/form-data':
              return parse_multipart(fp, pdict, separator=separator)
          elif ctype == 'application/x-www-form-urlencoded':
              clength = int(environ['CONTENT_LENGTH'])
              if maxlen and clength > maxlen:
                  raise ValueError('Maximum content length exceeded')
              qs = fp.read(clength).decode(encoding)
          else:
              qs = ''                     # Unknown content-type
          if 'QUERY_STRING' in environ:
              if qs: qs = qs + '&'
              qs = qs + environ['QUERY_STRING']
          elif sys.argv[1:]:
              if qs: qs = qs + '&'
              qs = qs + sys.argv[1]
          environ['QUERY_STRING'] = qs    # XXX Shouldn't, really
      elif 'QUERY_STRING' in environ:
          qs = environ['QUERY_STRING']
      else:
          if sys.argv[1:]:
              qs = sys.argv[1]
          else:
              qs = ""
          environ['QUERY_STRING'] = qs    # XXX Shouldn't, really
      return urllib.parse.parse_qs(qs, keep_blank_values, strict_parsing,
                                   encoding=encoding, separator=separator)
  
  
  def parse_multipart(fp, pdict, encoding="utf-8", errors="replace", separator='&'):
      """Parse multipart input.
  
      Arguments:
      fp   : input file
      pdict: dictionary containing other parameters of content-type header
      encoding, errors: request encoding and error handler, passed to
          FieldStorage
  
      Returns a dictionary just like parse_qs(): keys are the field names, each
      value is a list of values for that field. For non-file fields, the value
      is a list of strings.
      """
      # RFC 2026, Section 5.1 : The "multipart" boundary delimiters are always
      # represented as 7bit US-ASCII.
      boundary = pdict['boundary'].decode('ascii')
      ctype = "multipart/form-data; boundary={}".format(boundary)
      headers = Message()
      headers.set_type(ctype)
      try:
          headers['Content-Length'] = pdict['CONTENT-LENGTH']
      except KeyError:
          pass
      fs = FieldStorage(fp, headers=headers, encoding=encoding, errors=errors,
          environ={'REQUEST_METHOD': 'POST'}, separator=separator)
      return {k: fs.getlist(k) for k in fs}
  
  def _parseparam(s):
      while s[:1] == ';':
          s = s[1:]
          end = s.find(';')
          while end > 0 and (s.count('"', 0, end) - s.count('\\"', 0, end)) % 2:
              end = s.find(';', end + 1)
          if end < 0:
              end = len(s)
          f = s[:end]
          yield f.strip()
          s = s[end:]
  
  def parse_header(line):
      """Parse a Content-type like header.
  
      Return the main content-type and a dictionary of options.
  
      """
      parts = _parseparam(';' + line)
      key = parts.__next__()
      pdict = {}
      for p in parts:
          i = p.find('=')
          if i >= 0:
              name = p[:i].strip().lower()
              value = p[i+1:].strip()
              if len(value) >= 2 and value[0] == value[-1] == '"':
                  value = value[1:-1]
                  value = value.replace('\\\\', '\\').replace('\\"', '"')
              pdict[name] = value
      return key, pdict
  
  
  # Classes for field storage
  # =========================
  
  class MiniFieldStorage:
  
      """Like FieldStorage, for use when no file uploads are possible."""
  
      # Dummy attributes
      filename = None
      list = None
      type = None
      file = None
      type_options = {}
      disposition = None
      disposition_options = {}
      headers = {}
  
      def __init__(self, name, value):
          """Constructor from field name and value."""
          self.name = name
          self.value = value
          # self.file = StringIO(value)
  
      def __repr__(self):
          """Return printable representation."""
          return "MiniFieldStorage(%r, %r)" % (self.name, self.value)
  
  
  class FieldStorage:
  
      """Store a sequence of fields, reading multipart/form-data.
  
      This class provides naming, typing, files stored on disk, and
      more.  At the top level, it is accessible like a dictionary, whose
      keys are the field names.  (Note: None can occur as a field name.)
      The items are either a Python list (if there's multiple values) or
      another FieldStorage or MiniFieldStorage object.  If it's a single
      object, it has the following attributes:
  
      name: the field name, if specified; otherwise None
  
      filename: the filename, if specified; otherwise None; this is the
          client side filename, *not* the file name on which it is
          stored (that's a temporary file you don't deal with)
  
      value: the value as a *string*; for file uploads, this
          transparently reads the file every time you request the value
          and returns *bytes*
  
      file: the file(-like) object from which you can read the data *as
          bytes* ; None if the data is stored a simple string
  
      type: the content-type, or None if not specified
  
      type_options: dictionary of options specified on the content-type
          line
  
      disposition: content-disposition, or None if not specified
  
      disposition_options: dictionary of corresponding options
  
      headers: a dictionary(-like) object (sometimes email.message.Message or a
          subclass thereof) containing *all* headers
  
      The class is subclassable, mostly for the purpose of overriding
      the make_file() method, which is called internally to come up with
      a file open for reading and writing.  This makes it possible to
      override the default choice of storing all files in a temporary
      directory and unlinking them as soon as they have been opened.
  
      """
      def __init__(self, fp=None, headers=None, outerboundary=b'',
                   environ=os.environ, keep_blank_values=0, strict_parsing=0,
                   limit=None, encoding='utf-8', errors='replace',
                   max_num_fields=None, separator='&'):
          """Constructor.  Read multipart/* until last part.
  
          Arguments, all optional:
  
          fp              : file pointer; default: sys.stdin.buffer
              (not used when the request method is GET)
              Can be :
              1. a TextIOWrapper object
              2. an object whose read() and readline() methods return bytes
  
          headers         : header dictionary-like object; default:
              taken from environ as per CGI spec
  
          outerboundary   : terminating multipart boundary
              (for internal use only)
  
          environ         : environment dictionary; default: os.environ
  
          keep_blank_values: flag indicating whether blank values in
              percent-encoded forms should be treated as blank strings.
              A true value indicates that blanks should be retained as
              blank strings.  The default false value indicates that
              blank values are to be ignored and treated as if they were
              not included.
  
          strict_parsing: flag indicating what to do with parsing errors.
              If false (the default), errors are silently ignored.
              If true, errors raise a ValueError exception.
  
          limit : used internally to read parts of multipart/form-data forms,
              to exit from the reading loop when reached. It is the difference
              between the form content-length and the number of bytes already
              read
  
          encoding, errors : the encoding and error handler used to decode the
              binary stream to strings. Must be the same as the charset defined
              for the page sending the form (content-type : meta http-equiv or
              header)
  
          max_num_fields: int. If set, then __init__ throws a ValueError
              if there are more than n fields read by parse_qsl().
  
          """
          method = 'GET'
          self.keep_blank_values = keep_blank_values
          self.strict_parsing = strict_parsing
          self.max_num_fields = max_num_fields
          self.separator = separator
          if 'REQUEST_METHOD' in environ:
              method = environ['REQUEST_METHOD'].upper()
          self.qs_on_post = None
          if method == 'GET' or method == 'HEAD':
              if 'QUERY_STRING' in environ:
                  qs = environ['QUERY_STRING']
              elif sys.argv[1:]:
                  qs = sys.argv[1]
              else:
                  qs = ""
              qs = qs.encode(locale.getpreferredencoding(), 'surrogateescape')
              fp = BytesIO(qs)
              if headers is None:
                  headers = {'content-type':
                             "application/x-www-form-urlencoded"}
          if headers is None:
              headers = {}
              if method == 'POST':
                  # Set default content-type for POST to what's traditional
                  headers['content-type'] = "application/x-www-form-urlencoded"
              if 'CONTENT_TYPE' in environ:
                  headers['content-type'] = environ['CONTENT_TYPE']
              if 'QUERY_STRING' in environ:
                  self.qs_on_post = environ['QUERY_STRING']
              if 'CONTENT_LENGTH' in environ:
                  headers['content-length'] = environ['CONTENT_LENGTH']
          else:
              if not (isinstance(headers, (Mapping, Message))):
                  raise TypeError("headers must be mapping or an instance of "
                                  "email.message.Message")
          self.headers = headers
          if fp is None:
              self.fp = sys.stdin.buffer
          # self.fp.read() must return bytes
          elif isinstance(fp, TextIOWrapper):
              self.fp = fp.buffer
          else:
              if not (hasattr(fp, 'read') and hasattr(fp, 'readline')):
                  raise TypeError("fp must be file pointer")
              self.fp = fp
  
          self.encoding = encoding
          self.errors = errors
  
          if not isinstance(outerboundary, bytes):
              raise TypeError('outerboundary must be bytes, not %s'
                              % type(outerboundary).__name__)
          self.outerboundary = outerboundary
  
          self.bytes_read = 0
          self.limit = limit
  
          # Process content-disposition header
          cdisp, pdict = "", {}
          if 'content-disposition' in self.headers:
              cdisp, pdict = parse_header(self.headers['content-disposition'])
          self.disposition = cdisp
          self.disposition_options = pdict
          self.name = None
          if 'name' in pdict:
              self.name = pdict['name']
          self.filename = None
          if 'filename' in pdict:
              self.filename = pdict['filename']
          self._binary_file = self.filename is not None
  
          # Process content-type header
          #
          # Honor any existing content-type header.  But if there is no
          # content-type header, use some sensible defaults.  Assume
          # outerboundary is "" at the outer level, but something non-false
          # inside a multi-part.  The default for an inner part is text/plain,
          # but for an outer part it should be urlencoded.  This should catch
          # bogus clients which erroneously forget to include a content-type
          # header.
          #
          # See below for what we do if there does exist a content-type header,
          # but it happens to be something we don't understand.
          if 'content-type' in self.headers:
              ctype, pdict = parse_header(self.headers['content-type'])
          elif self.outerboundary or method != 'POST':
              ctype, pdict = "text/plain", {}
          else:
              ctype, pdict = 'application/x-www-form-urlencoded', {}
          self.type = ctype
          self.type_options = pdict
          if 'boundary' in pdict:
              self.innerboundary = pdict['boundary'].encode(self.encoding,
                                                            self.errors)
          else:
              self.innerboundary = b""
  
          clen = -1
          if 'content-length' in self.headers:
              try:
                  clen = int(self.headers['content-length'])
              except ValueError:
                  pass
              if maxlen and clen > maxlen:
                  raise ValueError('Maximum content length exceeded')
          self.length = clen
          if self.limit is None and clen >= 0:
              self.limit = clen
  
          self.list = self.file = None
          self.done = 0
          if ctype == 'application/x-www-form-urlencoded':
              self.read_urlencoded()
          elif ctype[:10] == 'multipart/':
              self.read_multi(environ, keep_blank_values, strict_parsing)
          else:
              self.read_single()
  
      def __del__(self):
          try:
              self.file.close()
          except AttributeError:
              pass
  
      def __enter__(self):
          return self
  
      def __exit__(self, *args):
          self.file.close()
  
      def __repr__(self):
          """Return a printable representation."""
          return "FieldStorage(%r, %r, %r)" % (
                  self.name, self.filename, self.value)
  
      def __iter__(self):
          return iter(self.keys())
  
      def __getattr__(self, name):
          if name != 'value':
              raise AttributeError(name)
          if self.file:
              self.file.seek(0)
              value = self.file.read()
              self.file.seek(0)
          elif self.list is not None:
              value = self.list
          else:
              value = None
          return value
  
      def __getitem__(self, key):
          """Dictionary style indexing."""
          if self.list is None:
              raise TypeError("not indexable")
          found = []
          for item in self.list:
              if item.name == key: found.append(item)
          if not found:
              raise KeyError(key)
          if len(found) == 1:
              return found[0]
          else:
              return found
  
      def getvalue(self, key, default=None):
          """Dictionary style get() method, including 'value' lookup."""
          if key in self:
              value = self[key]
              if isinstance(value, list):
                  return [x.value for x in value]
              else:
                  return value.value
          else:
              return default
  
      def getfirst(self, key, default=None):
          """ Return the first value received."""
          if key in self:
              value = self[key]
              if isinstance(value, list):
                  return value[0].value
              else:
                  return value.value
          else:
              return default
  
      def getlist(self, key):
          """ Return list of received values."""
          if key in self:
              value = self[key]
              if isinstance(value, list):
                  return [x.value for x in value]
              else:
                  return [value.value]
          else:
              return []
  
      def keys(self):
          """Dictionary style keys() method."""
          if self.list is None:
              raise TypeError("not indexable")
          return list(set(item.name for item in self.list))
  
      def __contains__(self, key):
          """Dictionary style __contains__ method."""
          if self.list is None:
              raise TypeError("not indexable")
          return any(item.name == key for item in self.list)
  
      def __len__(self):
          """Dictionary style len(x) support."""
          return len(self.keys())
  
      def __bool__(self):
          if self.list is None:
              raise TypeError("Cannot be converted to bool.")
          return bool(self.list)
  
      def read_urlencoded(self):
          """Internal: read data in query string format."""
          qs = self.fp.read(self.length)
          if not isinstance(qs, bytes):
              raise ValueError("%s should return bytes, got %s" \
                               % (self.fp, type(qs).__name__))
          qs = qs.decode(self.encoding, self.errors)
          if self.qs_on_post:
              qs += '&' + self.qs_on_post
          query = urllib.parse.parse_qsl(
              qs, self.keep_blank_values, self.strict_parsing,
              encoding=self.encoding, errors=self.errors,
              max_num_fields=self.max_num_fields, separator=self.separator)
          self.list = [MiniFieldStorage(key, value) for key, value in query]
          self.skip_lines()
  
      FieldStorageClass = None
  
      def read_multi(self, environ, keep_blank_values, strict_parsing):
          """Internal: read a part that is itself multipart."""
          ib = self.innerboundary
          if not valid_boundary(ib):
              raise ValueError('Invalid boundary in multipart form: %r' % (ib,))
          self.list = []
          if self.qs_on_post:
              query = urllib.parse.parse_qsl(
                  self.qs_on_post, self.keep_blank_values, self.strict_parsing,
                  encoding=self.encoding, errors=self.errors,
                  max_num_fields=self.max_num_fields, separator=self.separator)
              self.list.extend(MiniFieldStorage(key, value) for key, value in query)
  
          klass = self.FieldStorageClass or self.__class__
          first_line = self.fp.readline() # bytes
          if not isinstance(first_line, bytes):
              raise ValueError("%s should return bytes, got %s" \
                               % (self.fp, type(first_line).__name__))
          self.bytes_read += len(first_line)
  
          # Ensure that we consume the file until we've hit our inner boundary
          while (first_line.strip() != (b"--" + self.innerboundary) and
                  first_line):
              first_line = self.fp.readline()
              self.bytes_read += len(first_line)
  
          # Propagate max_num_fields into the sub class appropriately
          max_num_fields = self.max_num_fields
          if max_num_fields is not None:
              max_num_fields -= len(self.list)
  
          while True:
              parser = FeedParser()
              hdr_text = b""
              while True:
                  data = self.fp.readline()
                  hdr_text += data
                  if not data.strip():
                      break
              if not hdr_text:
                  break
              # parser takes strings, not bytes
              self.bytes_read += len(hdr_text)
              parser.feed(hdr_text.decode(self.encoding, self.errors))
              headers = parser.close()
  
              # Some clients add Content-Length for part headers, ignore them
              if 'content-length' in headers:
                  del headers['content-length']
  
              limit = None if self.limit is None \
                  else self.limit - self.bytes_read
              part = klass(self.fp, headers, ib, environ, keep_blank_values,
                           strict_parsing, limit,
                           self.encoding, self.errors, max_num_fields, self.separator)
  
              if max_num_fields is not None:
                  max_num_fields -= 1
                  if part.list:
                      max_num_fields -= len(part.list)
                  if max_num_fields < 0:
                      raise ValueError('Max number of fields exceeded')
  
              self.bytes_read += part.bytes_read
              self.list.append(part)
              if part.done or self.bytes_read >= self.length > 0:
                  break
          self.skip_lines()
  
      def read_single(self):
          """Internal: read an atomic part."""
          if self.length >= 0:
              self.read_binary()
              self.skip_lines()
          else:
              self.read_lines()
          self.file.seek(0)
  
      bufsize = 8*1024            # I/O buffering size for copy to file
  
      def read_binary(self):
          """Internal: read binary data."""
          self.file = self.make_file()
          todo = self.length
          if todo >= 0:
              while todo > 0:
                  data = self.fp.read(min(todo, self.bufsize)) # bytes
                  if not isinstance(data, bytes):
                      raise ValueError("%s should return bytes, got %s"
                                       % (self.fp, type(data).__name__))
                  self.bytes_read += len(data)
                  if not data:
                      self.done = -1
                      break
                  self.file.write(data)
                  todo = todo - len(data)
  
      def read_lines(self):
          """Internal: read lines until EOF or outerboundary."""
          if self._binary_file:
              self.file = self.__file = BytesIO() # store data as bytes for files
          else:
              self.file = self.__file = StringIO() # as strings for other fields
          if self.outerboundary:
              self.read_lines_to_outerboundary()
          else:
              self.read_lines_to_eof()
  
      def __write(self, line):
          """line is always bytes, not string"""
          if self.__file is not None:
              if self.__file.tell() + len(line) > 1000:
                  self.file = self.make_file()
                  data = self.__file.getvalue()
                  self.file.write(data)
                  self.__file = None
          if self._binary_file:
              # keep bytes
              self.file.write(line)
          else:
              # decode to string
              self.file.write(line.decode(self.encoding, self.errors))
  
      def read_lines_to_eof(self):
          """Internal: read lines until EOF."""
          while 1:
              line = self.fp.readline(1<<16) # bytes
              self.bytes_read += len(line)
              if not line:
                  self.done = -1
                  break
              self.__write(line)
  
      def read_lines_to_outerboundary(self):
          """Internal: read lines until outerboundary.
          Data is read as bytes: boundaries and line ends must be converted
          to bytes for comparisons.
          """
          next_boundary = b"--" + self.outerboundary
          last_boundary = next_boundary + b"--"
          delim = b""
          last_line_lfend = True
          _read = 0
          while 1:
  
              if self.limit is not None and 0 <= self.limit <= _read:
                  break
              line = self.fp.readline(1<<16) # bytes
              self.bytes_read += len(line)
              _read += len(line)
              if not line:
                  self.done = -1
                  break
              if delim == b"\r":
                  line = delim + line
                  delim = b""
              if line.startswith(b"--") and last_line_lfend:
                  strippedline = line.rstrip()
                  if strippedline == next_boundary:
                      break
                  if strippedline == last_boundary:
                      self.done = 1
                      break
              odelim = delim
              if line.endswith(b"\r\n"):
                  delim = b"\r\n"
                  line = line[:-2]
                  last_line_lfend = True
              elif line.endswith(b"\n"):
                  delim = b"\n"
                  line = line[:-1]
                  last_line_lfend = True
              elif line.endswith(b"\r"):
                  # We may interrupt \r\n sequences if they span the 2**16
                  # byte boundary
                  delim = b"\r"
                  line = line[:-1]
                  last_line_lfend = False
              else:
                  delim = b""
                  last_line_lfend = False
              self.__write(odelim + line)
  
      def skip_lines(self):
          """Internal: skip lines until outer boundary if defined."""
          if not self.outerboundary or self.done:
              return
          next_boundary = b"--" + self.outerboundary
          last_boundary = next_boundary + b"--"
          last_line_lfend = True
          while True:
              line = self.fp.readline(1<<16)
              self.bytes_read += len(line)
              if not line:
                  self.done = -1
                  break
              if line.endswith(b"--") and last_line_lfend:
                  strippedline = line.strip()
                  if strippedline == next_boundary:
                      break
                  if strippedline == last_boundary:
                      self.done = 1
                      break
              last_line_lfend = line.endswith(b'\n')
  
      def make_file(self):
          """Overridable: return a readable & writable file.
  
          The file will be used as follows:
          - data is written to it
          - seek(0)
          - data is read from it
  
          The file is opened in binary mode for files, in text mode
          for other fields
  
          This version opens a temporary file for reading and writing,
          and immediately deletes (unlinks) it.  The trick (on Unix!) is
          that the file can still be used, but it can't be opened by
          another process, and it will automatically be deleted when it
          is closed or when the current process terminates.
  
          If you want a more permanent file, you derive a class which
          overrides this method.  If you want a visible temporary file
          that is nevertheless automatically deleted when the script
          terminates, try defining a __del__ method in a derived class
          which unlinks the temporary files you have created.
  
          """
          if self._binary_file:
              return tempfile.TemporaryFile("wb+")
          else:
              return tempfile.TemporaryFile("w+",
                  encoding=self.encoding, newline = '\n')
  
  
  # Test/debug code
  # ===============
  
  def test(environ=os.environ):
      """Robust test CGI script, usable as main program.
  
      Write minimal HTTP headers and dump all information provided to
      the script in HTML form.
  
      """
      print("Content-type: text/html")
      print()
      sys.stderr = sys.stdout
      try:
          form = FieldStorage()   # Replace with other classes to test those
          print_directory()
          print_arguments()
          print_form(form)
          print_environ(environ)
          print_environ_usage()
          def f():
              exec("testing print_exception() -- <I>italics?</I>")
          def g(f=f):
              f()
          print("<H3>What follows is a test, not an actual exception:</H3>")
          g()
      except:
          print_exception()
  
      print("<H1>Second try with a small maxlen...</H1>")
  
      global maxlen
      maxlen = 50
      try:
          form = FieldStorage()   # Replace with other classes to test those
          print_directory()
          print_arguments()
          print_form(form)
          print_environ(environ)
      except:
          print_exception()
  
  def print_exception(type=None, value=None, tb=None, limit=None):
      if type is None:
          type, value, tb = sys.exc_info()
      import traceback
      print()
      print("<H3>Traceback (most recent call last):</H3>")
      list = traceback.format_tb(tb, limit) + \
             traceback.format_exception_only(type, value)
      print("<PRE>%s<B>%s</B></PRE>" % (
          html.escape("".join(list[:-1])),
          html.escape(list[-1]),
          ))
      del tb
  
  def print_environ(environ=os.environ):
      """Dump the shell environment as HTML."""
      keys = sorted(environ.keys())
      print()
      print("<H3>Shell Environment:</H3>")
      print("<DL>")
      for key in keys:
          print("<DT>", html.escape(key), "<DD>", html.escape(environ[key]))
      print("</DL>")
      print()
  
  def print_form(form):
      """Dump the contents of a form as HTML."""
      keys = sorted(form.keys())
      print()
      print("<H3>Form Contents:</H3>")
      if not keys:
          print("<P>No form fields.")
      print("<DL>")
      for key in keys:
          print("<DT>" + html.escape(key) + ":", end=' ')
          value = form[key]
          print("<i>" + html.escape(repr(type(value))) + "</i>")
          print("<DD>" + html.escape(repr(value)))
      print("</DL>")
      print()
  
  def print_directory():
      """Dump the current directory as HTML."""
      print()
      print("<H3>Current Working Directory:</H3>")
      try:
          pwd = os.getcwd()
      except OSError as msg:
          print("OSError:", html.escape(str(msg)))
      else:
          print(html.escape(pwd))
      print()
  
  def print_arguments():
      print()
      print("<H3>Command Line Arguments:</H3>")
      print()
      print(sys.argv)
      print()
  
  def print_environ_usage():
      """Dump a list of environment variables used by CGI as HTML."""
      print("""
  <H3>These environment variables could have been set:</H3>
  <UL>
  <LI>AUTH_TYPE
  <LI>CONTENT_LENGTH
  <LI>CONTENT_TYPE
  <LI>DATE_GMT
  <LI>DATE_LOCAL
  <LI>DOCUMENT_NAME
  <LI>DOCUMENT_ROOT
  <LI>DOCUMENT_URI
  <LI>GATEWAY_INTERFACE
  <LI>LAST_MODIFIED
  <LI>PATH
  <LI>PATH_INFO
  <LI>PATH_TRANSLATED
  <LI>QUERY_STRING
  <LI>REMOTE_ADDR
  <LI>REMOTE_HOST
  <LI>REMOTE_IDENT
  <LI>REMOTE_USER
  <LI>REQUEST_METHOD
  <LI>SCRIPT_NAME
  <LI>SERVER_NAME
  <LI>SERVER_PORT
  <LI>SERVER_PROTOCOL
  <LI>SERVER_ROOT
  <LI>SERVER_SOFTWARE
  </UL>
  In addition, HTTP headers sent by the server may be passed in the
  environment as well.  Here are some common variable names:
  <UL>
  <LI>HTTP_ACCEPT
  <LI>HTTP_CONNECTION
  <LI>HTTP_HOST
  <LI>HTTP_PRAGMA
  <LI>HTTP_REFERER
  <LI>HTTP_USER_AGENT
  </UL>
  """)
  
  
  # Utilities
  # =========
  
  def valid_boundary(s):
      import re
      if isinstance(s, bytes):
          _vb_pattern = b"^[ -~]{0,200}[!-~]$"
      else:
          _vb_pattern = "^[ -~]{0,200}[!-~]$"
      return re.match(_vb_pattern, s)
  
  # Invoke mainline
  # ===============
  
  # Call test() when this file is run as a script (not imported as a module)
  if __name__ == '__main__':
      test()
  