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cgi.py
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executable file
·992 lines (854 loc) · 32.8 KB
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#! /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):
"""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.
"""
if fp is None:
fp = sys.stdin
# field keys and values (except for files) are returned as strings
# an encoding is required to deco
FBC8
de 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)
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)
def parse_multipart(fp, pdict, encoding="utf-8", errors="replace"):
"""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)
headers['Content-Length'] = pdict['CONTENT-LENGTH']
fs = FieldStorage(fp, headers=headers, encoding=encoding, errors=errors,
environ={'REQUEST_METHOD': 'POST'})
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):
"""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
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)
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)
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_n
FF8
um_fields)
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):
FBC8
"""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 _read >= self.limit:
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()