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SF Patch 569574 - enhancements to cgitb for plain text display

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This commit is contained in:
Skip Montanaro 2003-06-17 12:58:31 +00:00
parent d05abdec7b
commit 364ca40c2a
3 changed files with 108 additions and 18 deletions
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14
Doc/lib/libcgitb.tex
View file

@ -12,9 +12,12 @@
\index{exceptions!in CGI scripts}
\index{tracebacks!in CGI scripts}
The \module{cgitb} module provides a special exception handler for CGI
scripts. After this module is activated, if an uncaught exception occurs,
a detailed, formatted report will be sent to the Web browser. The report
The \module{cgitb} module provides a special exception handler for Python
scripts. (It's name is a bit misleading. It was originally designed to
display extensive traceback information in HTML for CGI scripts. It was
later generalized to also display this information in plain text.) After
this module is activated, if an uncaught exception occurs, a detailed,
formatted report will be displayed. The report
includes a traceback showing excerpts of the source code for each level,
as well as the values of the arguments and local variables to currently
running functions, to help you debug the problem. Optionally, you can
@ -32,7 +35,7 @@ to a file for later analysis.
\begin{funcdesc}{enable}{\optional{display\optional{, logdir\optional{,
context}}}}
context\optional{, format}}}}}
This function causes the \module{cgitb} module to take over the
interpreter's default handling for exceptions by setting the
value of \code{\refmodule{sys}.excepthook}.
@ -46,6 +49,9 @@ to a file for later analysis.
The optional argument \var{context} is the number of lines of
context to display around the current line of source code in the
traceback; this defaults to \code{5}.
If the optional argument \var{format} is \code{"html"}, the output is
formatted as HTML. Any other value forces plain text output. The default
value is \code{"html"}.
\end{funcdesc}
\begin{funcdesc}{handler}{\optional{info}}

109
Lib/cgitb.py
View file

@ -1,20 +1,25 @@
"""Handle exceptions in CGI scripts by formatting tracebacks into nice HTML.
"""More comprehensive traceback formatting for Python scripts.
To enable this module, do:
import cgitb; cgitb.enable()
at the top of your CGI script. The optional arguments to enable() are:
at the top of your script. The optional arguments to enable() are:
display - if true, tracebacks are displayed in the web browser
logdir - if set, tracebacks are written to files in this directory
context - number of lines of source code to show for each stack frame
format - 'text' or 'html' controls the output format
By default, tracebacks are displayed but not saved, and context is 5.
By default, tracebacks are displayed but not saved, the context is 5 lines
and the output format is 'html' (for backwards compatibility with the
original use of this module)
Alternatively, if you have caught an exception and want cgitb to display it
for you, call cgitb.handler(). The optional argument to handler() is a 3-item
tuple (etype, evalue, etb) just like the value of sys.exc_info()."""
for you, call cgitb.handler(). The optional argument to handler() is a
3-item tuple (etype, evalue, etb) just like the value of sys.exc_info().
The default handler displays output as HTML.
"""
__author__ = 'Ka-Ping Yee'
__version__ = '$Revision$'
@ -160,30 +165,105 @@ def reader(lnum=[lnum]):
-->
''' % ''.join(traceback.format_exception(etype, evalue, etb))
def text((etype, evalue, etb), context=5):
"""Return a plain text document describing a given traceback."""
import os, types, time, traceback, linecache, inspect, pydoc
if type(etype) is types.ClassType:
etype = etype.__name__
pyver = 'Python ' + sys.version.split()[0] + ': ' + sys.executable
date = time.ctime(time.time())
head = "%s\n%s\n%s\n" % (str(etype), pyver, date) + '''
A problem occurred in a Python script. Here is the sequence of
function calls leading up to the error, in the order they occurred.
'''
frames = []
records = inspect.getinnerframes(etb, context)
for frame, file, lnum, func, lines, index in records:
file = file and os.path.abspath(file) or '?'
args, varargs, varkw, locals = inspect.getargvalues(frame)
call = ''
if func != '?':
call = 'in ' + func + \
inspect.formatargvalues(args, varargs, varkw, locals,
formatvalue=lambda value: '=' + pydoc.text.repr(value))
highlight = {}
def reader(lnum=[lnum]):
highlight[lnum[0]] = 1
try: return linecache.getline(file, lnum[0])
finally: lnum[0] += 1
vars = scanvars(reader, frame, locals)
rows = [' %s %s' % (file, call)]
if index is not None:
i = lnum - index
for line in lines:
num = '%5d ' % i
rows.append(num+line.rstrip())
i += 1
done, dump = {}, []
for name, where, value in vars:
if name in done: continue
done[name] = 1
if value is not __UNDEF__:
if where == 'global': name = 'global ' + name
elif where == 'local': name = name
else: name = where + name.split('.')[-1]
dump.append('%s = %s' % (name, pydoc.text.repr(value)))
else:
dump.append(name + ' undefined')
rows.append('\n'.join(dump))
frames.append('\n%s\n' % '\n'.join(rows))
exception = ['%s: %s' % (str(etype), str(evalue))]
if type(evalue) is types.InstanceType:
for name in dir(evalue):
value = pydoc.text.repr(getattr(evalue, name))
exception.append('\n%s%s = %s' % (" "*4, name, value))
import traceback
return head + ''.join(frames) + ''.join(exception) + '''
The above is a description of an error in a Python program. Here is
the original traceback:
%s
''' % ''.join(traceback.format_exception(etype, evalue, etb))
class Hook:
"""A hook to replace sys.excepthook that shows tracebacks in HTML."""
def __init__(self, display=1, logdir=None, context=5, file=None):
def __init__(self, display=1, logdir=None, context=5, file=None,
format="html"):
self.display = display # send tracebacks to browser if true
self.logdir = logdir # log tracebacks to files if not None
self.context = context # number of source code lines per frame
self.file = file or sys.stdout # place to send the output
self.format = format
def __call__(self, etype, evalue, etb):
self.handle((etype, evalue, etb))
def handle(self, info=None):
info = info or sys.exc_info()
self.file.write(reset())
if self.format == "html":
self.file.write(reset())
formatter = (self.format=="html") and html or text
plain = False
try:
text, doc = 0, html(info, self.context)
doc = formatter(info, self.context)
except: # just in case something goes wrong
import traceback
text, doc = 1, ''.join(traceback.format_exception(*info))
doc = ''.join(traceback.format_exception(*info))
plain = True
if self.display:
if text:
if plain:
doc = doc.replace('&', '&amp;').replace('<', '&lt;')
self.file.write('<pre>' + doc + '</pre>\n')
else:
@ -193,8 +273,8 @@ def handle(self, info=None):
if self.logdir is not None:
import os, tempfile
(fd, path) = tempfile.mkstemp(suffix=['.html', '.txt'][text],
dir=self.logdir)
suffix = ['.html', '.txt'][self.format=="html"]
(fd, path) = tempfile.mkstemp(suffix=suffix, dir=self.logdir)
try:
file = os.fdopen(fd, 'w')
file.write(doc)
@ -208,10 +288,11 @@ def handle(self, info=None):
except: pass
handler = Hook().handle
def enable(display=1, logdir=None, context=5):
def enable(display=1, logdir=None, context=5, format="html"):
"""Install an exception handler that formats tracebacks as HTML.
The optional argument 'display' can be set to 0 to suppress sending the
traceback to the browser, and 'logdir' can be set to a directory to cause
tracebacks to be written to files there."""
sys.excepthook = Hook(display, logdir, context)
sys.excepthook = Hook(display=display, logdir=logdir,
context=context, format=format)

3
Misc/NEWS
View file

@ -83,6 +83,9 @@ Extension modules
Library
-------
- The cgitb module has been extended to support plain text display (SF patch
569574).
- A brand new version of IDLE (from the IDLEfork project at
SourceForge) is now included as Lib/idlelib. The old Tools/idle is
no more.