Gitiles
Code Review Sign In
gerrit-public.fairphone.software / platform / external / python / cpython3 / fa78d0fbe45a7f16d5d30c3d4e3ad30dc4933e8f / . / Lib / cgitb.py
blob: 619bdfc25a1b27d1fa5a32f56fdde7d9a18da5a0 [file] [log] [blame]
Ka-Ping Yee6b5a48d2001-08-18 04:04:50 +0000[diff] [blame]1"""Handle exceptions in CGI scripts by formatting tracebacks into nice HTML.
2
3To enable this module, do:
4
5 import cgitb; cgitb.enable()
6
7at 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
Ka-Ping Yee83205972001-08-21 06:53:01 +0000[diff] [blame]11 context - number of lines of source code to show for each stack frame
Ka-Ping Yee6b5a48d2001-08-18 04:04:50 +0000[diff] [blame]12
Ka-Ping Yee83205972001-08-21 06:53:01 +0000[diff] [blame]13By default, tracebacks are displayed but not saved, and context is 5.
Ka-Ping Yee6b5a48d2001-08-18 04:04:50 +0000[diff] [blame]14
15Alternatively, if you have caught an exception and want cgitb to display it
16for you, call cgitb.handle(). The optional argument to handle() is a 3-item
17tuple (etype, evalue, etb) just like the value of sys.exc_info()."""
18
19__author__ = 'Ka-Ping Yee'
20__version__ = '$Revision$'
21
Ka-Ping Yeefa78d0f2001-12-04 18:45:17 +0000[diff] [blame^]22import sys
23
Ka-Ping Yee6b5a48d2001-08-18 04:04:50 +0000[diff] [blame]24def reset():
25 """Return a string that resets the CGI and browser to a known state."""
26 return '''<!--: spam
27Content-Type: text/html
28
Ka-Ping Yee83205972001-08-21 06:53:01 +0000[diff] [blame]29<body bgcolor="#f0f0f8"><font color="#f0f0f8" size="-5"> -->
30<body bgcolor="#f0f0f8"><font color="#f0f0f8" size="-5"> --> -->
Ka-Ping Yee6b5a48d2001-08-18 04:04:50 +0000[diff] [blame]31</font> </font> </font> </script> </object> </blockquote> </pre>
32</table> </table> </table> </table> </table> </font> </font> </font>'''
33
Ka-Ping Yee83205972001-08-21 06:53:01 +0000[diff] [blame]34__UNDEF__ = [] # a special sentinel object
35def small(text): return '<small>' + text + '</small>'
36def strong(text): return '<strong>' + text + '</strong>'
37def grey(text): return '<font color="#909090">' + text + '</font>'
38
39def 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
47def 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
69def html((etype, evalue, etb), context=5):
70 """Return a nice HTML document describing a given traceback."""
Ka-Ping Yeefa78d0f2001-12-04 18:45:17 +0000[diff] [blame^]71 import os, types, time, traceback, linecache, inspect, pydoc
Ka-Ping Yee6b5a48d2001-08-18 04:04:50 +0000[diff] [blame]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())
Ka-Ping Yee83205972001-08-21 06:53:01 +0000[diff] [blame]77 head = '<body bgcolor="#f0f0f8">' + pydoc.html.heading(
Ka-Ping Yee6b5a48d2001-08-18 04:04:50 +0000[diff] [blame]78 '<big><big><strong>%s</strong></big></big>' % str(etype),
Ka-Ping Yee83205972001-08-21 06:53:01 +0000[diff] [blame]79 '#ffffff', '#6622aa', pyver + '<br>' + date) + '''
80<p>A problem occurred in a Python script. Here is the sequence of
81function calls leading up to the error, in the order they occurred.'''
Ka-Ping Yee6b5a48d2001-08-18 04:04:50 +0000[diff] [blame]82
Ka-Ping Yee83205972001-08-21 06:53:01 +0000[diff] [blame]83 indent = '<tt>' + small('&nbsp;' * 5) + '&nbsp;</tt>'
Ka-Ping Yee6b5a48d2001-08-18 04:04:50 +0000[diff] [blame]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 '?'
Ka-Ping Yee83205972001-08-21 06:53:01 +0000[diff] [blame]88 link = '<a href="file://%s">%s</a>' % (file, pydoc.html.escape(file))
Ka-Ping Yee6b5a48d2001-08-18 04:04:50 +0000[diff] [blame]89 args, varargs, varkw, locals = inspect.getargvalues(frame)
Ka-Ping Yee83205972001-08-21 06:53:01 +0000[diff] [blame]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))
Ka-Ping Yee6b5a48d2001-08-18 04:04:50 +0000[diff] [blame]95
Ka-Ping Yee83205972001-08-21 06:53:01 +0000[diff] [blame]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)
Ka-Ping Yee6b5a48d2001-08-18 04:04:50 +0000[diff] [blame]102
Ka-Ping Yee83205972001-08-21 06:53:01 +0000[diff] [blame]103 rows = ['<tr><td bgcolor="#d8bbff">%s%s %s</td></tr>' %
104 ('<big>&nbsp;</big>', link, call)]
Ka-Ping Yee6b5a48d2001-08-18 04:04:50 +0000[diff] [blame]105 if index is not None:
106 i = lnum - index
107 for line in lines:
Ka-Ping Yee83205972001-08-21 06:53:01 +0000[diff] [blame]108 num = small('&nbsp;' * (5-len(str(i))) + str(i)) + '&nbsp;'
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
Ka-Ping Yee6b5a48d2001-08-18 04:04:50 +0000[diff] [blame]115
Ka-Ping Yee83205972001-08-21 06:53:01 +0000[diff] [blame]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&nbsp;= %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))]
Ka-Ping Yee6b5a48d2001-08-18 04:04:50 +0000[diff] [blame]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&nbsp;=\n%s' % (indent, name, value))
138
139 import traceback
Ka-Ping Yee6b5a48d2001-08-18 04:04:50 +0000[diff] [blame]140 return head + ''.join(frames) + ''.join(exception) + '''
141
142
Ka-Ping Yee83205972001-08-21 06:53:01 +0000[diff] [blame]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:
Ka-Ping Yee6b5a48d2001-08-18 04:04:50 +0000[diff] [blame]146
147%s
148-->
Ka-Ping Yee83205972001-08-21 06:53:01 +0000[diff] [blame]149''' % ''.join(traceback.format_exception(etype, evalue, etb))
Ka-Ping Yee6b5a48d2001-08-18 04:04:50 +0000[diff] [blame]150
151class Hook:
Ka-Ping Yee83205972001-08-21 06:53:01 +0000[diff] [blame]152 """A hook to replace sys.excepthook that shows tracebacks in HTML."""
153
Ka-Ping Yeefa78d0f2001-12-04 18:45:17 +0000[diff] [blame^]154 def __init__(self, display=1, logdir=None, context=5, file=None):
Ka-Ping Yee6b5a48d2001-08-18 04:04:50 +0000[diff] [blame]155 self.display = display # send tracebacks to browser if true
156 self.logdir = logdir # log tracebacks to files if not None
Ka-Ping Yee83205972001-08-21 06:53:01 +0000[diff] [blame]157 self.context = context # number of source code lines per frame
Ka-Ping Yeefa78d0f2001-12-04 18:45:17 +0000[diff] [blame^]158 self.file = file or sys.stdout # place to send the output
Ka-Ping Yee6b5a48d2001-08-18 04:04:50 +0000[diff] [blame]159
160 def __call__(self, etype, evalue, etb):
Ka-Ping Yee6b5a48d2001-08-18 04:04:50 +0000[diff] [blame]161 self.handle((etype, evalue, etb))
162
163 def handle(self, info=None):
Ka-Ping Yee6b5a48d2001-08-18 04:04:50 +0000[diff] [blame]164 info = info or sys.exc_info()
Ka-Ping Yeefa78d0f2001-12-04 18:45:17 +0000[diff] [blame^]165 self.file.write(reset())
Ka-Ping Yee6b5a48d2001-08-18 04:04:50 +0000[diff] [blame]166
167 try:
Ka-Ping Yee83205972001-08-21 06:53:01 +0000[diff] [blame]168 text, doc = 0, html(info, self.context)
Ka-Ping Yee6b5a48d2001-08-18 04:04:50 +0000[diff] [blame]169 except: # just in case something goes wrong
170 import traceback
Ka-Ping Yee83205972001-08-21 06:53:01 +0000[diff] [blame]171 text, doc = 1, ''.join(traceback.format_exception(*info))
Ka-Ping Yee6b5a48d2001-08-18 04:04:50 +0000[diff] [blame]172
173 if self.display:
174 if text:
175 doc = doc.replace('&', '&amp;').replace('<', '&lt;')
Ka-Ping Yeefa78d0f2001-12-04 18:45:17 +0000[diff] [blame^]176 self.file.write('<pre>' + doc + '</pre>\n')
Ka-Ping Yee6b5a48d2001-08-18 04:04:50 +0000[diff] [blame]177 else:
Ka-Ping Yeefa78d0f2001-12-04 18:45:17 +0000[diff] [blame^]178 self.file.write(doc + '\n')
Ka-Ping Yee6b5a48d2001-08-18 04:04:50 +0000[diff] [blame]179 else:
Ka-Ping Yeefa78d0f2001-12-04 18:45:17 +0000[diff] [blame^]180 self.file.write('<p>A problem occurred in a Python script.\n')
Ka-Ping Yee6b5a48d2001-08-18 04:04:50 +0000[diff] [blame]181
182 if self.logdir is not None:
Ka-Ping Yee83205972001-08-21 06:53:01 +0000[diff] [blame]183 import os, tempfile
Ka-Ping Yee6b5a48d2001-08-18 04:04:50 +0000[diff] [blame]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()
Ka-Ping Yeefa78d0f2001-12-04 18:45:17 +0000[diff] [blame^]190 msg = '<p> %s contains the description of this error.' % path
Ka-Ping Yee6b5a48d2001-08-18 04:04:50 +0000[diff] [blame]191 except:
Ka-Ping Yeefa78d0f2001-12-04 18:45:17 +0000[diff] [blame^]192 msg = '<p> Tried to save traceback to %s, but failed.' % path
193 self.file.write(msg + '\n')
194 try:
195 self.file.flush()
196 except: pass
Ka-Ping Yee6b5a48d2001-08-18 04:04:50 +0000[diff] [blame]197
198handler = Hook().handle
Ka-Ping Yee83205972001-08-21 06:53:01 +0000[diff] [blame]199def 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."""
Ka-Ping Yee83205972001-08-21 06:53:01 +0000[diff] [blame]205 sys.excepthook = Hook(display, logdir, context)