| Ka-Ping Yee | 6b5a48d | 2001-08-18 04:04:50 +0000 | [diff] [blame^] | 1 | """Handle exceptions in CGI scripts by formatting tracebacks into nice HTML. |
| 2 | |
| 3 | To enable this module, do: |
| 4 | |
| 5 | import cgitb; cgitb.enable() |
| 6 | |
| 7 | at the top of your CGI script. The optional arguments to enable() are: |
| 8 | |
| 9 | display - if true, tracebacks are displayed in the web browser |
| 10 | logdir - if set, tracebacks are written to files in this directory |
| 11 | |
| 12 | By default, tracebacks are displayed but not written to files. |
| 13 | |
| 14 | Alternatively, if you have caught an exception and want cgitb to display it |
| 15 | for you, call cgitb.handle(). The optional argument to handle() is a 3-item |
| 16 | tuple (etype, evalue, etb) just like the value of sys.exc_info().""" |
| 17 | |
| 18 | __author__ = 'Ka-Ping Yee' |
| 19 | __version__ = '$Revision$' |
| 20 | |
| 21 | def reset(): |
| 22 | """Return a string that resets the CGI and browser to a known state.""" |
| 23 | return '''<!--: spam |
| 24 | Content-Type: text/html |
| 25 | |
| 26 | <body bgcolor="#f0f0ff"><font color="#f0f0ff" size="-5"> --> |
| 27 | <body bgcolor="#f0f0ff"><font color="#f0f0ff" size="-5"> --> --> |
| 28 | </font> </font> </font> </script> </object> </blockquote> </pre> |
| 29 | </table> </table> </table> </table> </table> </font> </font> </font>''' |
| 30 | |
| 31 | def html(etype, evalue, etb, context=5): |
| 32 | """Return a nice HTML document describing the traceback.""" |
| 33 | import sys, os, types, time, traceback |
| 34 | import keyword, tokenize, linecache, inspect, pydoc |
| 35 | |
| 36 | if type(etype) is types.ClassType: |
| 37 | etype = etype.__name__ |
| 38 | pyver = 'Python ' + sys.version.split()[0] + ': ' + sys.executable |
| 39 | date = time.ctime(time.time()) |
| 40 | head = '<body bgcolor="#f0f0ff">' + pydoc.html.heading( |
| 41 | '<big><big><strong>%s</strong></big></big>' % str(etype), |
| 42 | '#ffffff', '#aa55cc', pyver + '<br>' + date) + ''' |
| 43 | <p>A problem occurred in a Python script. |
| 44 | Here is the sequence of function calls leading up to |
| 45 | the error, with the most recent (innermost) call last.''' |
| 46 | |
| 47 | indent = '<tt><small>' + ' ' * 5 + '</small> </tt>' |
| 48 | frames = [] |
| 49 | records = inspect.getinnerframes(etb, context) |
| 50 | for frame, file, lnum, func, lines, index in records: |
| 51 | file = file and os.path.abspath(file) or '?' |
| 52 | link = '<a href="file:%s">%s</a>' % (file, pydoc.html.escape(file)) |
| 53 | args, varargs, varkw, locals = inspect.getargvalues(frame) |
| 54 | if func == '?': |
| 55 | call = '' |
| 56 | else: |
| 57 | def eqrepr(value): return '=' + pydoc.html.repr(value) |
| 58 | call = 'in <strong>%s</strong>' % func + inspect.formatargvalues( |
| 59 | args, varargs, varkw, locals, formatvalue=eqrepr) |
| 60 | |
| 61 | names = [] |
| 62 | def tokeneater(type, token, start, end, line): |
| 63 | if type == tokenize.NAME and token not in keyword.kwlist: |
| 64 | if token not in names: names.append(token) |
| 65 | if type == tokenize.NEWLINE: raise IndexError |
| 66 | def linereader(lnum=[lnum]): |
| 67 | line = linecache.getline(file, lnum[0]) |
| 68 | lnum[0] += 1 |
| 69 | return line |
| 70 | |
| 71 | try: |
| 72 | tokenize.tokenize(linereader, tokeneater) |
| 73 | except IndexError: pass |
| 74 | lvals = [] |
| 75 | for name in names: |
| 76 | if name in frame.f_code.co_varnames: |
| 77 | if locals.has_key(name): |
| 78 | value = pydoc.html.repr(locals[name]) |
| 79 | else: |
| 80 | value = '<em>undefined</em>' |
| 81 | name = '<strong>%s</strong>' % name |
| 82 | else: |
| 83 | if frame.f_globals.has_key(name): |
| 84 | value = pydoc.html.repr(frame.f_globals[name]) |
| 85 | else: |
| 86 | value = '<em>undefined</em>' |
| 87 | name = '<em>global</em> <strong>%s</strong>' % name |
| 88 | lvals.append('%s = %s' % (name, value)) |
| 89 | if lvals: |
| 90 | lvals = indent + ''' |
| 91 | <small><font color="#909090">%s</font></small><br>''' % (', '.join(lvals)) |
| 92 | else: |
| 93 | lvals = '' |
| 94 | |
| 95 | level = ''' |
| 96 | <table width="100%%" bgcolor="#d8bbff" cellspacing=0 cellpadding=2 border=0> |
| 97 | <tr><td>%s %s</td></tr></table>\n''' % (link, call) |
| 98 | excerpt = [] |
| 99 | if index is not None: |
| 100 | i = lnum - index |
| 101 | for line in lines: |
| 102 | num = '<small><font color="#909090">%s</font></small>' % ( |
| 103 | ' ' * (5-len(str(i))) + str(i)) |
| 104 | line = '<tt>%s %s</tt>' % (num, pydoc.html.preformat(line)) |
| 105 | if i == lnum: |
| 106 | line = ''' |
| 107 | <table width="100%%" bgcolor="#ffccee" cellspacing=0 cellpadding=0 border=0> |
| 108 | <tr><td>%s</td></tr></table>\n''' % line |
| 109 | excerpt.append('\n' + line) |
| 110 | if i == lnum: |
| 111 | excerpt.append(lvals) |
| 112 | i = i + 1 |
| 113 | frames.append('<p>' + level + '\n'.join(excerpt)) |
| 114 | |
| 115 | exception = ['<p><strong>%s</strong>: %s' % (str(etype), str(evalue))] |
| 116 | if type(evalue) is types.InstanceType: |
| 117 | for name in dir(evalue): |
| 118 | value = pydoc.html.repr(getattr(evalue, name)) |
| 119 | exception.append('\n<br>%s%s =\n%s' % (indent, name, value)) |
| 120 | |
| 121 | import traceback |
| 122 | plaintrace = ''.join(traceback.format_exception(etype, evalue, etb)) |
| 123 | |
| 124 | return head + ''.join(frames) + ''.join(exception) + ''' |
| 125 | |
| 126 | |
| 127 | <!-- The above is a description of an error that occurred in a Python program. |
| 128 | It is formatted for display in a Web browser because it appears that |
| 129 | we are running in a CGI environment. In case you are viewing this |
| 130 | message outside of a Web browser, here is the original error traceback: |
| 131 | |
| 132 | %s |
| 133 | --> |
| 134 | ''' % plaintrace |
| 135 | |
| 136 | class Hook: |
| 137 | def __init__(self, display=1, logdir=None): |
| 138 | self.display = display # send tracebacks to browser if true |
| 139 | self.logdir = logdir # log tracebacks to files if not None |
| 140 | |
| 141 | def __call__(self, etype, evalue, etb): |
| 142 | """This hook can replace sys.excepthook (for Python 2.1 or higher).""" |
| 143 | self.handle((etype, evalue, etb)) |
| 144 | |
| 145 | def handle(self, info=None): |
| 146 | import sys, os |
| 147 | info = info or sys.exc_info() |
| 148 | text = 0 |
| 149 | print reset() |
| 150 | |
| 151 | try: |
| 152 | doc = html(*info) |
| 153 | except: # just in case something goes wrong |
| 154 | import traceback |
| 155 | doc = ''.join(traceback.format_exception(*info)) |
| 156 | text = 1 |
| 157 | |
| 158 | if self.display: |
| 159 | if text: |
| 160 | doc = doc.replace('&', '&').replace('<', '<') |
| 161 | print '<pre>', doc, '</pre>' |
| 162 | else: |
| 163 | print doc |
| 164 | else: |
| 165 | print '<p>A problem occurred in a Python script.' |
| 166 | |
| 167 | if self.logdir is not None: |
| 168 | import tempfile |
| 169 | name = tempfile.mktemp(['.html', '.txt'][text]) |
| 170 | path = os.path.join(self.logdir, os.path.basename(name)) |
| 171 | try: |
| 172 | file = open(path, 'w') |
| 173 | file.write(doc) |
| 174 | file.close() |
| 175 | print '<p>%s contains the description of this error.' % path |
| 176 | except: |
| 177 | print '<p>Tried to write to %s, but failed.' % path |
| 178 | |
| 179 | handler = Hook().handle |
| 180 | def enable(display=1, logdir=None): |
| 181 | import sys |
| 182 | sys.excepthook = Hook(display, logdir) |