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.
  """
  
  # XXX Perhaps there should be a slimmed version that doesn't contain
  # all those backwards compatible and debugging classes and functions?
  
  # 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 operator import attrgetter
  import sys
  import os
  import urllib
  import UserDict
  import urlparse
  
  from warnings import filterwarnings, catch_warnings, warn
  with catch_warnings():
      if sys.py3kwarning:
          filterwarnings("ignore", ".*mimetools has been removed",
                         DeprecationWarning)
          filterwarnings("ignore", ".*rfc822 has been removed",
                         DeprecationWarning)
      import mimetools
      import rfc822
  
  try:
      from cStringIO import StringIO
  except ImportError:
      from StringIO import StringIO
  
  __all__ = ["MiniFieldStorage", "FieldStorage", "FormContentDict",
             "SvFormContentDict", "InterpFormContentDict", "FormContent",
             "parse", "parse_qs", "parse_qsl", "parse_multipart",
             "parse_header", "print_exception", "print_environ",
             "print_form", "print_directory", "print_arguments",
             "print_environ_usage", "escape"]
  
  # 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 logfp, log
      if logfile and not logfp:
          try:
              logfp = open(logfile, "a")
          except IOError:
              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
  
  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):
      """Parse a query in the environment or from a file (default stdin)
  
          Arguments, all optional:
  
          fp              : file pointer; default: sys.stdin
  
          environ         : environment dictionary; default: os.environ
  
          keep_blank_values: flag indicating whether blank values in
              URL 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.
      """
      if fp is None:
          fp = sys.stdin
      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)
          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)
          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 urlparse.parse_qs(qs, keep_blank_values, strict_parsing)
  
  
  # parse query string function called from urlparse,
  # this is done in order to maintain backward compatiblity.
  
  def parse_qs(qs, keep_blank_values=0, strict_parsing=0):
      """Parse a query given as a string argument."""
      warn("cgi.parse_qs is deprecated, use urlparse.parse_qs instead",
           PendingDeprecationWarning, 2)
      return urlparse.parse_qs(qs, keep_blank_values, strict_parsing)
  
  
  def parse_qsl(qs, keep_blank_values=0, strict_parsing=0):
      """Parse a query given as a string argument."""
      warn("cgi.parse_qsl is deprecated, use urlparse.parse_qsl instead",
           PendingDeprecationWarning, 2)
      return urlparse.parse_qsl(qs, keep_blank_values, strict_parsing)
  
  def parse_multipart(fp, pdict):
      """Parse multipart input.
  
      Arguments:
      fp   : input file
      pdict: dictionary containing other parameters of content-type header
  
      Returns a dictionary just like parse_qs(): keys are the field names, each
      value is a list of values for that field.  This is easy to use but not
      much good if you are expecting megabytes to be uploaded -- in that case,
      use the FieldStorage class instead which is much more flexible.  Note
      that content-type is the raw, unparsed contents of the content-type
      header.
  
      XXX This does not parse nested multipart parts -- use FieldStorage for
      that.
  
      XXX This should really be subsumed by FieldStorage altogether -- no
      point in having two implementations of the same parsing algorithm.
      Also, FieldStorage protects itself better against certain DoS attacks
      by limiting the size of the data read in one chunk.  The API here
      does not support that kind of protection.  This also affects parse()
      since it can call parse_multipart().
  
      """
      boundary = ""
      if 'boundary' in pdict:
          boundary = pdict['boundary']
      if not valid_boundary(boundary):
          raise ValueError,  ('Invalid boundary in multipart form: %r'
                              % (boundary,))
  
      nextpart = "--" + boundary
      lastpart = "--" + boundary + "--"
      partdict = {}
      terminator = ""
  
      while terminator != lastpart:
          bytes = -1
          data = None
          if terminator:
              # At start of next part.  Read headers first.
              headers = mimetools.Message(fp)
              clength = headers.getheader('content-length')
              if clength:
                  try:
                      bytes = int(clength)
                  except ValueError:
                      pass
              if bytes > 0:
                  if maxlen and bytes > maxlen:
                      raise ValueError, 'Maximum content length exceeded'
                  data = fp.read(bytes)
              else:
                  data = ""
          # Read lines until end of part.
          lines = []
          while 1:
              line = fp.readline()
              if not line:
                  terminator = lastpart # End outer loop
                  break
              if line[:2] == "--":
                  terminator = line.strip()
                  if terminator in (nextpart, lastpart):
                      break
              lines.append(line)
          # Done with part.
          if data is None:
              continue
          if bytes < 0:
              if lines:
                  # Strip final line terminator
                  line = lines[-1]
                  if line[-2:] == "\r\n":
                      line = line[:-2]
                  elif line[-1:] == "\n":
                      line = line[:-1]
                  lines[-1] = line
                  data = "".join(lines)
          line = headers['content-disposition']
          if not line:
              continue
          key, params = parse_header(line)
          if key != 'form-data':
              continue
          if 'name' in params:
              name = params['name']
          else:
              continue
          if name in partdict:
              partdict[name].append(data)
          else:
              partdict[name] = [data]
  
      return partdict
  
  
  def _parseparam(s):
      while s[:1] == ';':
          s = s[1:]
          end = s.find(';')
          while end > 0 and 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
  
      file: the file(-like) object from which you can read the data;
          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 rfc822.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="",
                   environ=os.environ, keep_blank_values=0, strict_parsing=0):
          """Constructor.  Read multipart/* until last part.
  
          Arguments, all optional:
  
          fp              : file pointer; default: sys.stdin
              (not used when the request method is GET)
  
          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
              URL 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.
  
          """
          method = 'GET'
          self.keep_blank_values = keep_blank_values
          self.strict_parsing = strict_parsing
          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 = ""
              fp = StringIO(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']
          self.fp = fp or sys.stdin
          self.headers = headers
          self.outerboundary = outerboundary
  
          # 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']
  
          # 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
          self.innerboundary = ""
          if 'boundary' in pdict:
              self.innerboundary = pdict['boundary']
          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
  
          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 __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 type(value) is type([]):
                  return map(attrgetter('value'), 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 type(value) is type([]):
                  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 type(value) is type([]):
                  return map(attrgetter('value'), 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 has_key(self, key):
          """Dictionary style has_key() method."""
          if self.list is None:
              raise TypeError, "not indexable"
          return any(item.name == key 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 __nonzero__(self):
          return bool(self.list)
  
      def read_urlencoded(self):
          """Internal: read data in query string format."""
          qs = self.fp.read(self.length)
          if self.qs_on_post:
              qs += '&' + self.qs_on_post
          self.list = list = []
          for key, value in urlparse.parse_qsl(qs, self.keep_blank_values,
                                              self.strict_parsing):
              list.append(MiniFieldStorage(key, value))
          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:
              for key, value in urlparse.parse_qsl(self.qs_on_post,
                                  self.keep_blank_values, self.strict_parsing):
                  self.list.append(MiniFieldStorage(key, value))
              FieldStorageClass = None
  
          klass = self.FieldStorageClass or self.__class__
          part = klass(self.fp, {}, ib,
                       environ, keep_blank_values, strict_parsing)
          # Throw first part away
          while not part.done:
              headers = rfc822.Message(self.fp)
              part = klass(self.fp, headers, ib,
                           environ, keep_blank_values, strict_parsing)
              self.list.append(part)
          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('b')
          todo = self.length
          if todo >= 0:
              while todo > 0:
                  data = self.fp.read(min(todo, self.bufsize))
                  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."""
          self.file = self.__file = StringIO()
          if self.outerboundary:
              self.read_lines_to_outerboundary()
          else:
              self.read_lines_to_eof()
  
      def __write(self, line):
          if self.__file is not None:
              if self.__file.tell() + len(line) > 1000:
                  self.file = self.make_file('')
                  self.file.write(self.__file.getvalue())
                  self.__file = None
          self.file.write(line)
  
      def read_lines_to_eof(self):
          """Internal: read lines until EOF."""
          while 1:
              line = self.fp.readline(1<<16)
              if not line:
                  self.done = -1
                  break
              self.__write(line)
  
      def read_lines_to_outerboundary(self):
          """Internal: read lines until outerboundary."""
          next = "--" + self.outerboundary
          last = next + "--"
          delim = ""
          last_line_lfend = True
          while 1:
              line = self.fp.readline(1<<16)
              if not line:
                  self.done = -1
                  break
              if line[:2] == "--" and last_line_lfend:
                  strippedline = line.strip()
                  if strippedline == next:
                      break
                  if strippedline == last:
                      self.done = 1
                      break
              odelim = delim
              if line[-2:] == "\r\n":
                  delim = "\r\n"
                  line = line[:-2]
                  last_line_lfend = True
              elif line[-1] == "\n":
                  delim = "\n"
                  line = line[:-1]
                  last_line_lfend = True
              else:
                  delim = ""
                  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 = "--" + self.outerboundary
          last = next + "--"
          last_line_lfend = True
          while 1:
              line = self.fp.readline(1<<16)
              if not line:
                  self.done = -1
                  break
              if line[:2] == "--" and last_line_lfend:
                  strippedline = line.strip()
                  if strippedline == next:
                      break
                  if strippedline == last:
                      self.done = 1
                      break
              last_line_lfend = line.endswith('\n')
  
      def make_file(self, binary=None):
          """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 'binary' argument is unused -- the file is always opened
          in binary mode.
  
          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.
  
          """
          import tempfile
          return tempfile.TemporaryFile("w+b")
  
  
  
  # Backwards Compatibility Classes
  # ===============================
  
  class FormContentDict(UserDict.UserDict):
      """Form content as dictionary with a list of values per field.
  
      form = FormContentDict()
  
      form[key] -> [value, value, ...]
      key in form -> Boolean
      form.keys() -> [key, key, ...]
      form.values() -> [[val, val, ...], [val, val, ...], ...]
      form.items() ->  [(key, [val, val, ...]), (key, [val, val, ...]), ...]
      form.dict == {key: [val, val, ...], ...}
  
      """
      def __init__(self, environ=os.environ, keep_blank_values=0, strict_parsing=0):
          self.dict = self.data = parse(environ=environ,
                                        keep_blank_values=keep_blank_values,
                                        strict_parsing=strict_parsing)
          self.query_string = environ['QUERY_STRING']
  
  
  class SvFormContentDict(FormContentDict):
      """Form content as dictionary expecting a single value per field.
  
      If you only expect a single value for each field, then form[key]
      will return that single value.  It will raise an IndexError if
      that expectation is not true.  If you expect a field to have
      possible multiple values, than you can use form.getlist(key) to
      get all of the values.  values() and items() are a compromise:
      they return single strings where there is a single value, and
      lists of strings otherwise.
  
      """
      def __getitem__(self, key):
          if len(self.dict[key]) > 1:
              raise IndexError, 'expecting a single value'
          return self.dict[key][0]
      def getlist(self, key):
          return self.dict[key]
      def values(self):
          result = []
          for value in self.dict.values():
              if len(value) == 1:
                  result.append(value[0])
              else: result.append(value)
          return result
      def items(self):
          result = []
          for key, value in self.dict.items():
              if len(value) == 1:
                  result.append((key, value[0]))
              else: result.append((key, value))
          return result
  
  
  class InterpFormContentDict(SvFormContentDict):
      """This class is present for backwards compatibility only."""
      def __getitem__(self, key):
          v = SvFormContentDict.__getitem__(self, key)
          if v[0] in '0123456789+-.':
              try: return int(v)
              except ValueError:
                  try: return float(v)
                  except ValueError: pass
          return v.strip()
      def values(self):
          result = []
          for key in self.keys():
              try:
                  result.append(self[key])
              except IndexError:
                  result.append(self.dict[key])
          return result
      def items(self):
          result = []
          for key in self.keys():
              try:
                  result.append((key, self[key]))
              except IndexError:
                  result.append((key, self.dict[key]))
          return result
  
  
  class FormContent(FormContentDict):
      """This class is present for backwards compatibility only."""
      def values(self, key):
          if key in self.dict :return self.dict[key]
          else: return None
      def indexed_value(self, key, location):
          if key in self.dict:
              if len(self.dict[key]) > location:
                  return self.dict[key][location]
              else: return None
          else: return None
      def value(self, key):
          if key in self.dict: return self.dict[key][0]
          else: return None
      def length(self, key):
          return len(self.dict[key])
      def stripped(self, key):
          if key in self.dict: return self.dict[key][0].strip()
          else: return None
      def pars(self):
          return self.dict
  
  
  # 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>" % (
          escape("".join(list[:-1])),
          escape(list[-1]),
          )
      del tb
  
  def print_environ(environ=os.environ):
      """Dump the shell environment as HTML."""
      keys = environ.keys()
      keys.sort()
      print
      print "<H3>Shell Environment:</H3>"
      print "<DL>"
      for key in keys:
          print "<DT>", escape(key), "<DD>", escape(environ[key])
      print "</DL>"
      print
  
  def print_form(form):
      """Dump the contents of a form as HTML."""
      keys = form.keys()
      keys.sort()
      print
      print "<H3>Form Contents:</H3>"
      if not keys:
          print "<P>No form fields."
      print "<DL>"
      for key in keys:
          print "<DT>" + escape(key) + ":",
          value = form[key]
          print "<i>" + escape(repr(type(value))) + "</i>"
          print "<DD>" + 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 os.error, msg:
          print "os.error:", escape(str(msg))
      else:
          print 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 escape(s, quote=None):
      '''Replace special characters "&", "<" and ">" to HTML-safe sequences.
      If the optional flag quote is true, the quotation mark character (")
      is also translated.'''
      s = s.replace("&", "&amp;") # Must be done first!
      s = s.replace("<", "&lt;")
      s = s.replace(">", "&gt;")
      if quote:
          s = s.replace('"', "&quot;")
      return s
  
  def valid_boundary(s, _vb_pattern="^[ -~]{0,200}[!-~]$"):
      import re
      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()
  