Mercurial > cpython-lru_cache-weakref
annotate Lib/cgitb.py @ 25838:8540887bcec6 2.2
Backport of 2.183:
Fix memory leak in add_subclass() found by NealN with valgrind.
| author | Guido van Rossum <guido@python.org> |
|---|---|
| date | Fri, 18 Oct 2002 13:42:21 +0000 |
| parents | 21c7d7565977 |
| children | dab8701bd3fa |
| rev | line source |
|---|---|
| 19365 | 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 | |
| 19421 | 11 context - number of lines of source code to show for each stack frame |
| 19365 | 12 |
| 19421 | 13 By default, tracebacks are displayed but not saved, and context is 5. |
| 19365 | 14 |
| 15 Alternatively, if you have caught an exception and want cgitb to display it | |
|
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16 for you, call cgitb.handler(). The optional argument to handler() is a 3-item |
| 19365 | 17 tuple (etype, evalue, etb) just like the value of sys.exc_info().""" |
| 18 | |
| 19 __author__ = 'Ka-Ping Yee' | |
| 20 __version__ = '$Revision$' | |
| 21 | |
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22 import sys |
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23 |
| 19365 | 24 def reset(): |
| 25 """Return a string that resets the CGI and browser to a known state.""" | |
| 26 return '''<!--: spam | |
| 27 Content-Type: text/html | |
| 28 | |
| 19421 | 29 <body bgcolor="#f0f0f8"><font color="#f0f0f8" size="-5"> --> |
| 30 <body bgcolor="#f0f0f8"><font color="#f0f0f8" size="-5"> --> --> | |
| 19365 | 31 </font> </font> </font> </script> </object> </blockquote> </pre> |
| 32 </table> </table> </table> </table> </table> </font> </font> </font>''' | |
| 33 | |
| 19421 | 34 __UNDEF__ = [] # a special sentinel object |
| 35 def small(text): return '<small>' + text + '</small>' | |
| 36 def strong(text): return '<strong>' + text + '</strong>' | |
| 37 def grey(text): return '<font color="#909090">' + text + '</font>' | |
| 38 | |
| 39 def lookup(name, frame, locals): | |
| 40 """Find the value for a given name in the given environment.""" | |
| 41 if name in locals: | |
| 42 return 'local', locals[name] | |
| 43 if name in frame.f_globals: | |
| 44 return 'global', frame.f_globals[name] | |
| 45 return None, __UNDEF__ | |
| 46 | |
| 47 def scanvars(reader, frame, locals): | |
| 48 """Scan one logical line of Python and look up values of variables used.""" | |
| 49 import tokenize, keyword | |
| 50 vars, lasttoken, parent, prefix = [], None, None, '' | |
| 51 for ttype, token, start, end, line in tokenize.generate_tokens(reader): | |
| 52 if ttype == tokenize.NEWLINE: break | |
| 53 if ttype == tokenize.NAME and token not in keyword.kwlist: | |
| 54 if lasttoken == '.': | |
| 55 if parent is not __UNDEF__: | |
| 56 value = getattr(parent, token, __UNDEF__) | |
| 57 vars.append((prefix + token, prefix, value)) | |
| 58 else: | |
| 59 where, value = lookup(token, frame, locals) | |
| 60 vars.append((token, where, value)) | |
| 61 elif token == '.': | |
| 62 prefix += lasttoken + '.' | |
| 63 parent = value | |
| 64 else: | |
| 65 parent, prefix = None, '' | |
| 66 lasttoken = token | |
| 67 return vars | |
| 68 | |
| 69 def html((etype, evalue, etb), context=5): | |
| 70 """Return a nice HTML document describing a given traceback.""" | |
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71 import os, types, time, traceback, linecache, inspect, pydoc |
| 19365 | 72 |
| 73 if type(etype) is types.ClassType: | |
| 74 etype = etype.__name__ | |
| 75 pyver = 'Python ' + sys.version.split()[0] + ': ' + sys.executable | |
| 76 date = time.ctime(time.time()) | |
| 19421 | 77 head = '<body bgcolor="#f0f0f8">' + pydoc.html.heading( |
| 19365 | 78 '<big><big><strong>%s</strong></big></big>' % str(etype), |
| 19421 | 79 '#ffffff', '#6622aa', pyver + '<br>' + date) + ''' |
| 80 <p>A problem occurred in a Python script. Here is the sequence of | |
| 81 function calls leading up to the error, in the order they occurred.''' | |
| 19365 | 82 |
| 19421 | 83 indent = '<tt>' + small(' ' * 5) + ' </tt>' |
| 19365 | 84 frames = [] |
| 85 records = inspect.getinnerframes(etb, context) | |
| 86 for frame, file, lnum, func, lines, index in records: | |
| 87 file = file and os.path.abspath(file) or '?' | |
| 19421 | 88 link = '<a href="file://%s">%s</a>' % (file, pydoc.html.escape(file)) |
| 19365 | 89 args, varargs, varkw, locals = inspect.getargvalues(frame) |
| 19421 | 90 call = '' |
| 91 if func != '?': | |
| 92 call = 'in ' + strong(func) + \ | |
| 93 inspect.formatargvalues(args, varargs, varkw, locals, | |
| 94 formatvalue=lambda value: '=' + pydoc.html.repr(value)) | |
| 19365 | 95 |
| 19421 | 96 highlight = {} |
| 97 def reader(lnum=[lnum]): | |
| 98 highlight[lnum[0]] = 1 | |
| 99 try: return linecache.getline(file, lnum[0]) | |
| 100 finally: lnum[0] += 1 | |
| 101 vars = scanvars(reader, frame, locals) | |
| 19365 | 102 |
| 19421 | 103 rows = ['<tr><td bgcolor="#d8bbff">%s%s %s</td></tr>' % |
| 104 ('<big> </big>', link, call)] | |
| 19365 | 105 if index is not None: |
| 106 i = lnum - index | |
| 107 for line in lines: | |
| 19421 | 108 num = small(' ' * (5-len(str(i))) + str(i)) + ' ' |
| 109 line = '<tt>%s%s</tt>' % (num, pydoc.html.preformat(line)) | |
| 110 if i in highlight: | |
| 111 rows.append('<tr><td bgcolor="#ffccee">%s</td></tr>' % line) | |
| 112 else: | |
| 113 rows.append('<tr><td>%s</td></tr>' % grey(line)) | |
| 114 i += 1 | |
| 19365 | 115 |
| 19421 | 116 done, dump = {}, [] |
| 117 for name, where, value in vars: | |
| 118 if name in done: continue | |
| 119 done[name] = 1 | |
| 120 if value is not __UNDEF__: | |
| 121 if where == 'global': name = '<em>global</em> ' + strong(name) | |
| 122 elif where == 'local': name = strong(name) | |
| 123 else: name = where + strong(name.split('.')[-1]) | |
| 124 dump.append('%s = %s' % (name, pydoc.html.repr(value))) | |
| 125 else: | |
| 126 dump.append(name + ' <em>undefined</em>') | |
| 127 | |
| 128 rows.append('<tr><td>%s</td></tr>' % small(grey(', '.join(dump)))) | |
| 129 frames.append('''<p> | |
| 130 <table width="100%%" cellspacing=0 cellpadding=0 border=0> | |
| 131 %s</table>''' % '\n'.join(rows)) | |
| 132 | |
| 133 exception = ['<p>%s: %s' % (strong(str(etype)), str(evalue))] | |
| 19365 | 134 if type(evalue) is types.InstanceType: |
| 135 for name in dir(evalue): | |
| 136 value = pydoc.html.repr(getattr(evalue, name)) | |
| 137 exception.append('\n<br>%s%s =\n%s' % (indent, name, value)) | |
| 138 | |
| 139 import traceback | |
| 140 return head + ''.join(frames) + ''.join(exception) + ''' | |
| 141 | |
| 142 | |
| 19421 | 143 <!-- The above is a description of an error in a Python program, formatted |
| 144 for a Web browser because the 'cgitb' module was enabled. In case you | |
| 145 are not reading this in a Web browser, here is the original traceback: | |
| 19365 | 146 |
| 147 %s | |
| 148 --> | |
| 19421 | 149 ''' % ''.join(traceback.format_exception(etype, evalue, etb)) |
| 19365 | 150 |
| 151 class Hook: | |
| 19421 | 152 """A hook to replace sys.excepthook that shows tracebacks in HTML.""" |
| 153 | |
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154 def __init__(self, display=1, logdir=None, context=5, file=None): |
| 19365 | 155 self.display = display # send tracebacks to browser if true |
| 156 self.logdir = logdir # log tracebacks to files if not None | |
| 19421 | 157 self.context = context # number of source code lines per frame |
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158 self.file = file or sys.stdout # place to send the output |
| 19365 | 159 |
| 160 def __call__(self, etype, evalue, etb): | |
| 161 self.handle((etype, evalue, etb)) | |
| 162 | |
| 163 def handle(self, info=None): | |
| 164 info = info or sys.exc_info() | |
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165 self.file.write(reset()) |
| 19365 | 166 |
| 167 try: | |
| 19421 | 168 text, doc = 0, html(info, self.context) |
| 19365 | 169 except: # just in case something goes wrong |
| 170 import traceback | |
| 19421 | 171 text, doc = 1, ''.join(traceback.format_exception(*info)) |
| 19365 | 172 |
| 173 if self.display: | |
| 174 if text: | |
| 175 doc = doc.replace('&', '&').replace('<', '<') | |
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176 self.file.write('<pre>' + doc + '</pre>\n') |
| 19365 | 177 else: |
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178 self.file.write(doc + '\n') |
| 19365 | 179 else: |
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180 self.file.write('<p>A problem occurred in a Python script.\n') |
| 19365 | 181 |
| 182 if self.logdir is not None: | |
| 19421 | 183 import os, tempfile |
| 19365 | 184 name = tempfile.mktemp(['.html', '.txt'][text]) |
| 185 path = os.path.join(self.logdir, os.path.basename(name)) | |
| 186 try: | |
| 187 file = open(path, 'w') | |
| 188 file.write(doc) | |
| 189 file.close() | |
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190 msg = '<p> %s contains the description of this error.' % path |
| 19365 | 191 except: |
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192 msg = '<p> Tried to save traceback to %s, but failed.' % path |
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193 self.file.write(msg + '\n') |
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194 try: |
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195 self.file.flush() |
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196 except: pass |
| 19365 | 197 |
| 198 handler = Hook().handle | |
| 19421 | 199 def enable(display=1, logdir=None, context=5): |
| 200 """Install an exception handler that formats tracebacks as HTML. | |
| 201 | |
| 202 The optional argument 'display' can be set to 0 to suppress sending the | |
| 203 traceback to the browser, and 'logdir' can be set to a directory to cause | |
| 204 tracebacks to be written to files there.""" | |
| 205 sys.excepthook = Hook(display, logdir, context) |