#! /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)

    import mimetools

    if sys.py3kwarning:

        filterwarnings("ignore", ".*rfc822 has been removed", DeprecationWarning)

    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 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()

