/usr/lib/python3/dist-packages/pexpect/spawnbase.py is in python3-pexpect 4.2.1-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 | import codecs
import os
import sys
import re
import errno
from .exceptions import ExceptionPexpect, EOF, TIMEOUT
from .expect import Expecter, searcher_string, searcher_re
PY3 = (sys.version_info[0] >= 3)
text_type = str if PY3 else unicode
class _NullCoder(object):
"""Pass bytes through unchanged."""
@staticmethod
def encode(b, final=False):
return b
@staticmethod
def decode(b, final=False):
return b
class SpawnBase(object):
"""A base class providing the backwards-compatible spawn API for Pexpect.
This should not be instantiated directly: use :class:`pexpect.spawn` or
:class:`pexpect.fdpexpect.fdspawn`.
"""
encoding = None
pid = None
flag_eof = False
def __init__(self, timeout=30, maxread=2000, searchwindowsize=None,
logfile=None, encoding=None, codec_errors='strict'):
self.stdin = sys.stdin
self.stdout = sys.stdout
self.stderr = sys.stderr
self.searcher = None
self.ignorecase = False
self.before = None
self.after = None
self.match = None
self.match_index = None
self.terminated = True
self.exitstatus = None
self.signalstatus = None
# status returned by os.waitpid
self.status = None
# the child file descriptor is initially closed
self.child_fd = -1
self.timeout = timeout
self.delimiter = EOF
self.logfile = logfile
# input from child (read_nonblocking)
self.logfile_read = None
# output to send (send, sendline)
self.logfile_send = None
# max bytes to read at one time into buffer
self.maxread = maxread
# This is the read buffer. See maxread.
self.buffer = bytes() if (encoding is None) else text_type()
# Data before searchwindowsize point is preserved, but not searched.
self.searchwindowsize = searchwindowsize
# Delay used before sending data to child. Time in seconds.
# Set this to None to skip the time.sleep() call completely.
self.delaybeforesend = 0.05
# Used by close() to give kernel time to update process status.
# Time in seconds.
self.delayafterclose = 0.1
# Used by terminate() to give kernel time to update process status.
# Time in seconds.
self.delayafterterminate = 0.1
# Delay in seconds to sleep after each call to read_nonblocking().
# Set this to None to skip the time.sleep() call completely: that
# would restore the behavior from pexpect-2.0 (for performance
# reasons or because you don't want to release Python's global
# interpreter lock).
self.delayafterread = 0.0001
self.softspace = False
self.name = '<' + repr(self) + '>'
self.closed = True
# Unicode interface
self.encoding = encoding
self.codec_errors = codec_errors
if encoding is None:
# bytes mode (accepts some unicode for backwards compatibility)
self._encoder = self._decoder = _NullCoder()
self.string_type = bytes
self.crlf = b'\r\n'
if PY3:
self.allowed_string_types = (bytes, str)
self.linesep = os.linesep.encode('ascii')
def write_to_stdout(b):
try:
return sys.stdout.buffer.write(b)
except AttributeError:
# If stdout has been replaced, it may not have .buffer
return sys.stdout.write(b.decode('ascii', 'replace'))
self.write_to_stdout = write_to_stdout
else:
self.allowed_string_types = (basestring,) # analysis:ignore
self.linesep = os.linesep
self.write_to_stdout = sys.stdout.write
else:
# unicode mode
self._encoder = codecs.getincrementalencoder(encoding)(codec_errors)
self._decoder = codecs.getincrementaldecoder(encoding)(codec_errors)
self.string_type = text_type
self.crlf = u'\r\n'
self.allowed_string_types = (text_type, )
if PY3:
self.linesep = os.linesep
else:
self.linesep = os.linesep.decode('ascii')
# This can handle unicode in both Python 2 and 3
self.write_to_stdout = sys.stdout.write
def _log(self, s, direction):
if self.logfile is not None:
self.logfile.write(s)
self.logfile.flush()
second_log = self.logfile_send if (direction=='send') else self.logfile_read
if second_log is not None:
second_log.write(s)
second_log.flush()
# For backwards compatibility, in bytes mode (when encoding is None)
# unicode is accepted for send and expect. Unicode mode is strictly unicode
# only.
def _coerce_expect_string(self, s):
if self.encoding is None and not isinstance(s, bytes):
return s.encode('ascii')
return s
def _coerce_send_string(self, s):
if self.encoding is None and not isinstance(s, bytes):
return s.encode('utf-8')
return s
def read_nonblocking(self, size=1, timeout=None):
"""This reads data from the file descriptor.
This is a simple implementation suitable for a regular file. Subclasses using ptys or pipes should override it.
The timeout parameter is ignored.
"""
try:
s = os.read(self.child_fd, size)
except OSError as err:
if err.args[0] == errno.EIO:
# Linux-style EOF
self.flag_eof = True
raise EOF('End Of File (EOF). Exception style platform.')
raise
if s == b'':
# BSD-style EOF
self.flag_eof = True
raise EOF('End Of File (EOF). Empty string style platform.')
s = self._decoder.decode(s, final=False)
self._log(s, 'read')
return s
def _pattern_type_err(self, pattern):
raise TypeError('got {badtype} ({badobj!r}) as pattern, must be one'
' of: {goodtypes}, pexpect.EOF, pexpect.TIMEOUT'\
.format(badtype=type(pattern),
badobj=pattern,
goodtypes=', '.join([str(ast)\
for ast in self.allowed_string_types])
)
)
def compile_pattern_list(self, patterns):
'''This compiles a pattern-string or a list of pattern-strings.
Patterns must be a StringType, EOF, TIMEOUT, SRE_Pattern, or a list of
those. Patterns may also be None which results in an empty list (you
might do this if waiting for an EOF or TIMEOUT condition without
expecting any pattern).
This is used by expect() when calling expect_list(). Thus expect() is
nothing more than::
cpl = self.compile_pattern_list(pl)
return self.expect_list(cpl, timeout)
If you are using expect() within a loop it may be more
efficient to compile the patterns first and then call expect_list().
This avoid calls in a loop to compile_pattern_list()::
cpl = self.compile_pattern_list(my_pattern)
while some_condition:
...
i = self.expect_list(cpl, timeout)
...
'''
if patterns is None:
return []
if not isinstance(patterns, list):
patterns = [patterns]
# Allow dot to match \n
compile_flags = re.DOTALL
if self.ignorecase:
compile_flags = compile_flags | re.IGNORECASE
compiled_pattern_list = []
for idx, p in enumerate(patterns):
if isinstance(p, self.allowed_string_types):
p = self._coerce_expect_string(p)
compiled_pattern_list.append(re.compile(p, compile_flags))
elif p is EOF:
compiled_pattern_list.append(EOF)
elif p is TIMEOUT:
compiled_pattern_list.append(TIMEOUT)
elif isinstance(p, type(re.compile(''))):
compiled_pattern_list.append(p)
else:
self._pattern_type_err(p)
return compiled_pattern_list
def expect(self, pattern, timeout=-1, searchwindowsize=-1, async=False):
'''This seeks through the stream until a pattern is matched. The
pattern is overloaded and may take several types. The pattern can be a
StringType, EOF, a compiled re, or a list of any of those types.
Strings will be compiled to re types. This returns the index into the
pattern list. If the pattern was not a list this returns index 0 on a
successful match. This may raise exceptions for EOF or TIMEOUT. To
avoid the EOF or TIMEOUT exceptions add EOF or TIMEOUT to the pattern
list. That will cause expect to match an EOF or TIMEOUT condition
instead of raising an exception.
If you pass a list of patterns and more than one matches, the first
match in the stream is chosen. If more than one pattern matches at that
point, the leftmost in the pattern list is chosen. For example::
# the input is 'foobar'
index = p.expect(['bar', 'foo', 'foobar'])
# returns 1('foo') even though 'foobar' is a "better" match
Please note, however, that buffering can affect this behavior, since
input arrives in unpredictable chunks. For example::
# the input is 'foobar'
index = p.expect(['foobar', 'foo'])
# returns 0('foobar') if all input is available at once,
# but returs 1('foo') if parts of the final 'bar' arrive late
When a match is found for the given pattern, the class instance
attribute *match* becomes an re.MatchObject result. Should an EOF
or TIMEOUT pattern match, then the match attribute will be an instance
of that exception class. The pairing before and after class
instance attributes are views of the data preceding and following
the matching pattern. On general exception, class attribute
*before* is all data received up to the exception, while *match* and
*after* attributes are value None.
When the keyword argument timeout is -1 (default), then TIMEOUT will
raise after the default value specified by the class timeout
attribute. When None, TIMEOUT will not be raised and may block
indefinitely until match.
When the keyword argument searchwindowsize is -1 (default), then the
value specified by the class maxread attribute is used.
A list entry may be EOF or TIMEOUT instead of a string. This will
catch these exceptions and return the index of the list entry instead
of raising the exception. The attribute 'after' will be set to the
exception type. The attribute 'match' will be None. This allows you to
write code like this::
index = p.expect(['good', 'bad', pexpect.EOF, pexpect.TIMEOUT])
if index == 0:
do_something()
elif index == 1:
do_something_else()
elif index == 2:
do_some_other_thing()
elif index == 3:
do_something_completely_different()
instead of code like this::
try:
index = p.expect(['good', 'bad'])
if index == 0:
do_something()
elif index == 1:
do_something_else()
except EOF:
do_some_other_thing()
except TIMEOUT:
do_something_completely_different()
These two forms are equivalent. It all depends on what you want. You
can also just expect the EOF if you are waiting for all output of a
child to finish. For example::
p = pexpect.spawn('/bin/ls')
p.expect(pexpect.EOF)
print p.before
If you are trying to optimize for speed then see expect_list().
On Python 3.4, or Python 3.3 with asyncio installed, passing
``async=True`` will make this return an :mod:`asyncio` coroutine,
which you can yield from to get the same result that this method would
normally give directly. So, inside a coroutine, you can replace this code::
index = p.expect(patterns)
With this non-blocking form::
index = yield from p.expect(patterns, async=True)
'''
compiled_pattern_list = self.compile_pattern_list(pattern)
return self.expect_list(compiled_pattern_list,
timeout, searchwindowsize, async)
def expect_list(self, pattern_list, timeout=-1, searchwindowsize=-1,
async=False):
'''This takes a list of compiled regular expressions and returns the
index into the pattern_list that matched the child output. The list may
also contain EOF or TIMEOUT(which are not compiled regular
expressions). This method is similar to the expect() method except that
expect_list() does not recompile the pattern list on every call. This
may help if you are trying to optimize for speed, otherwise just use
the expect() method. This is called by expect().
Like :meth:`expect`, passing ``async=True`` will make this return an
asyncio coroutine.
'''
if timeout == -1:
timeout = self.timeout
exp = Expecter(self, searcher_re(pattern_list), searchwindowsize)
if async:
from .async import expect_async
return expect_async(exp, timeout)
else:
return exp.expect_loop(timeout)
def expect_exact(self, pattern_list, timeout=-1, searchwindowsize=-1,
async=False):
'''This is similar to expect(), but uses plain string matching instead
of compiled regular expressions in 'pattern_list'. The 'pattern_list'
may be a string; a list or other sequence of strings; or TIMEOUT and
EOF.
This call might be faster than expect() for two reasons: string
searching is faster than RE matching and it is possible to limit the
search to just the end of the input buffer.
This method is also useful when you don't want to have to worry about
escaping regular expression characters that you want to match.
Like :meth:`expect`, passing ``async=True`` will make this return an
asyncio coroutine.
'''
if timeout == -1:
timeout = self.timeout
if (isinstance(pattern_list, self.allowed_string_types) or
pattern_list in (TIMEOUT, EOF)):
pattern_list = [pattern_list]
def prepare_pattern(pattern):
if pattern in (TIMEOUT, EOF):
return pattern
if isinstance(pattern, self.allowed_string_types):
return self._coerce_expect_string(pattern)
self._pattern_type_err(pattern)
try:
pattern_list = iter(pattern_list)
except TypeError:
self._pattern_type_err(pattern_list)
pattern_list = [prepare_pattern(p) for p in pattern_list]
exp = Expecter(self, searcher_string(pattern_list), searchwindowsize)
if async:
from .async import expect_async
return expect_async(exp, timeout)
else:
return exp.expect_loop(timeout)
def expect_loop(self, searcher, timeout=-1, searchwindowsize=-1):
'''This is the common loop used inside expect. The 'searcher' should be
an instance of searcher_re or searcher_string, which describes how and
what to search for in the input.
See expect() for other arguments, return value and exceptions. '''
exp = Expecter(self, searcher, searchwindowsize)
return exp.expect_loop(timeout)
def read(self, size=-1):
'''This reads at most "size" bytes from the file (less if the read hits
EOF before obtaining size bytes). If the size argument is negative or
omitted, read all data until EOF is reached. The bytes are returned as
a string object. An empty string is returned when EOF is encountered
immediately. '''
if size == 0:
return self.string_type()
if size < 0:
# delimiter default is EOF
self.expect(self.delimiter)
return self.before
# I could have done this more directly by not using expect(), but
# I deliberately decided to couple read() to expect() so that
# I would catch any bugs early and ensure consistant behavior.
# It's a little less efficient, but there is less for me to
# worry about if I have to later modify read() or expect().
# Note, it's OK if size==-1 in the regex. That just means it
# will never match anything in which case we stop only on EOF.
cre = re.compile(self._coerce_expect_string('.{%d}' % size), re.DOTALL)
# delimiter default is EOF
index = self.expect([cre, self.delimiter])
if index == 0:
### FIXME self.before should be ''. Should I assert this?
return self.after
return self.before
def readline(self, size=-1):
'''This reads and returns one entire line. The newline at the end of
line is returned as part of the string, unless the file ends without a
newline. An empty string is returned if EOF is encountered immediately.
This looks for a newline as a CR/LF pair (\\r\\n) even on UNIX because
this is what the pseudotty device returns. So contrary to what you may
expect you will receive newlines as \\r\\n.
If the size argument is 0 then an empty string is returned. In all
other cases the size argument is ignored, which is not standard
behavior for a file-like object. '''
if size == 0:
return self.string_type()
# delimiter default is EOF
index = self.expect([self.crlf, self.delimiter])
if index == 0:
return self.before + self.crlf
else:
return self.before
def __iter__(self):
'''This is to support iterators over a file-like object.
'''
return iter(self.readline, self.string_type())
def readlines(self, sizehint=-1):
'''This reads until EOF using readline() and returns a list containing
the lines thus read. The optional 'sizehint' argument is ignored.
Remember, because this reads until EOF that means the child
process should have closed its stdout. If you run this method on
a child that is still running with its stdout open then this
method will block until it timesout.'''
lines = []
while True:
line = self.readline()
if not line:
break
lines.append(line)
return lines
def fileno(self):
'''Expose file descriptor for a file-like interface
'''
return self.child_fd
def flush(self):
'''This does nothing. It is here to support the interface for a
File-like object. '''
pass
def isatty(self):
"""Overridden in subclass using tty"""
return False
# For 'with spawn(...) as child:'
def __enter__(self):
return self
def __exit__(self, etype, evalue, tb):
# We rely on subclasses to implement close(). If they don't, it's not
# clear what a context manager should do.
self.close()
|