861 lines
36 KiB
Python
861 lines
36 KiB
Python
|
import os
|
||
|
|
import sys
|
||
|
|
import time
|
||
|
|
import pty
|
||
|
|
import tty
|
||
|
|
import errno
|
||
|
|
import signal
|
||
|
|
from contextlib import contextmanager
|
||
|
|
|
||
|
|
import ptyprocess
|
||
|
|
from ptyprocess.ptyprocess import use_native_pty_fork
|
||
|
|
|
||
|
|
from .exceptions import ExceptionPexpect, EOF, TIMEOUT
|
||
|
|
from .spawnbase import SpawnBase
|
||
|
|
from .utils import (
|
||
|
|
which, split_command_line, select_ignore_interrupts, poll_ignore_interrupts
|
||
|
|
)
|
||
|
|
|
||
|
|
@contextmanager
|
||
|
|
def _wrap_ptyprocess_err():
|
||
|
|
"""Turn ptyprocess errors into our own ExceptionPexpect errors"""
|
||
|
|
try:
|
||
|
|
yield
|
||
|
|
except ptyprocess.PtyProcessError as e:
|
||
|
|
raise ExceptionPexpect(*e.args)
|
||
|
|
|
||
|
|
PY3 = (sys.version_info[0] >= 3)
|
||
|
|
|
||
|
|
class spawn(SpawnBase):
|
||
|
|
'''This is the main class interface for Pexpect. Use this class to start
|
||
|
|
and control child applications. '''
|
||
|
|
|
||
|
|
# This is purely informational now - changing it has no effect
|
||
|
|
use_native_pty_fork = use_native_pty_fork
|
||
|
|
|
||
|
|
def __init__(self, command, args=[], timeout=30, maxread=2000,
|
||
|
|
searchwindowsize=None, logfile=None, cwd=None, env=None,
|
||
|
|
ignore_sighup=False, echo=True, preexec_fn=None,
|
||
|
|
encoding=None, codec_errors='strict', dimensions=None,
|
||
|
|
use_poll=False):
|
||
|
|
'''This is the constructor. The command parameter may be a string that
|
||
|
|
includes a command and any arguments to the command. For example::
|
||
|
|
|
||
|
|
child = pexpect.spawn('/usr/bin/ftp')
|
||
|
|
child = pexpect.spawn('/usr/bin/ssh user@example.com')
|
||
|
|
child = pexpect.spawn('ls -latr /tmp')
|
||
|
|
|
||
|
|
You may also construct it with a list of arguments like so::
|
||
|
|
|
||
|
|
child = pexpect.spawn('/usr/bin/ftp', [])
|
||
|
|
child = pexpect.spawn('/usr/bin/ssh', ['user@example.com'])
|
||
|
|
child = pexpect.spawn('ls', ['-latr', '/tmp'])
|
||
|
|
|
||
|
|
After this the child application will be created and will be ready to
|
||
|
|
talk to. For normal use, see expect() and send() and sendline().
|
||
|
|
|
||
|
|
Remember that Pexpect does NOT interpret shell meta characters such as
|
||
|
|
redirect, pipe, or wild cards (``>``, ``|``, or ``*``). This is a
|
||
|
|
common mistake. If you want to run a command and pipe it through
|
||
|
|
another command then you must also start a shell. For example::
|
||
|
|
|
||
|
|
child = pexpect.spawn('/bin/bash -c "ls -l | grep LOG > logs.txt"')
|
||
|
|
child.expect(pexpect.EOF)
|
||
|
|
|
||
|
|
The second form of spawn (where you pass a list of arguments) is useful
|
||
|
|
in situations where you wish to spawn a command and pass it its own
|
||
|
|
argument list. This can make syntax more clear. For example, the
|
||
|
|
following is equivalent to the previous example::
|
||
|
|
|
||
|
|
shell_cmd = 'ls -l | grep LOG > logs.txt'
|
||
|
|
child = pexpect.spawn('/bin/bash', ['-c', shell_cmd])
|
||
|
|
child.expect(pexpect.EOF)
|
||
|
|
|
||
|
|
The maxread attribute sets the read buffer size. This is maximum number
|
||
|
|
of bytes that Pexpect will try to read from a TTY at one time. Setting
|
||
|
|
the maxread size to 1 will turn off buffering. Setting the maxread
|
||
|
|
value higher may help performance in cases where large amounts of
|
||
|
|
output are read back from the child. This feature is useful in
|
||
|
|
conjunction with searchwindowsize.
|
||
|
|
|
||
|
|
When the keyword argument *searchwindowsize* is None (default), the
|
||
|
|
full buffer is searched at each iteration of receiving incoming data.
|
||
|
|
The default number of bytes scanned at each iteration is very large
|
||
|
|
and may be reduced to collaterally reduce search cost. After
|
||
|
|
:meth:`~.expect` returns, the full buffer attribute remains up to
|
||
|
|
size *maxread* irrespective of *searchwindowsize* value.
|
||
|
|
|
||
|
|
When the keyword argument ``timeout`` is specified as a number,
|
||
|
|
(default: *30*), then :class:`TIMEOUT` will be raised after the value
|
||
|
|
specified has elapsed, in seconds, for any of the :meth:`~.expect`
|
||
|
|
family of method calls. When None, TIMEOUT will not be raised, and
|
||
|
|
:meth:`~.expect` may block indefinitely until match.
|
||
|
|
|
||
|
|
|
||
|
|
The logfile member turns on or off logging. All input and output will
|
||
|
|
be copied to the given file object. Set logfile to None to stop
|
||
|
|
logging. This is the default. Set logfile to sys.stdout to echo
|
||
|
|
everything to standard output. The logfile is flushed after each write.
|
||
|
|
|
||
|
|
Example log input and output to a file::
|
||
|
|
|
||
|
|
child = pexpect.spawn('some_command')
|
||
|
|
fout = open('mylog.txt','wb')
|
||
|
|
child.logfile = fout
|
||
|
|
|
||
|
|
Example log to stdout::
|
||
|
|
|
||
|
|
# In Python 2:
|
||
|
|
child = pexpect.spawn('some_command')
|
||
|
|
child.logfile = sys.stdout
|
||
|
|
|
||
|
|
# In Python 3, we'll use the ``encoding`` argument to decode data
|
||
|
|
# from the subprocess and handle it as unicode:
|
||
|
|
child = pexpect.spawn('some_command', encoding='utf-8')
|
||
|
|
child.logfile = sys.stdout
|
||
|
|
|
||
|
|
The logfile_read and logfile_send members can be used to separately log
|
||
|
|
the input from the child and output sent to the child. Sometimes you
|
||
|
|
don't want to see everything you write to the child. You only want to
|
||
|
|
log what the child sends back. For example::
|
||
|
|
|
||
|
|
child = pexpect.spawn('some_command')
|
||
|
|
child.logfile_read = sys.stdout
|
||
|
|
|
||
|
|
You will need to pass an encoding to spawn in the above code if you are
|
||
|
|
using Python 3.
|
||
|
|
|
||
|
|
To separately log output sent to the child use logfile_send::
|
||
|
|
|
||
|
|
child.logfile_send = fout
|
||
|
|
|
||
|
|
If ``ignore_sighup`` is True, the child process will ignore SIGHUP
|
||
|
|
signals. The default is False from Pexpect 4.0, meaning that SIGHUP
|
||
|
|
will be handled normally by the child.
|
||
|
|
|
||
|
|
The delaybeforesend helps overcome a weird behavior that many users
|
||
|
|
were experiencing. The typical problem was that a user would expect() a
|
||
|
|
"Password:" prompt and then immediately call sendline() to send the
|
||
|
|
password. The user would then see that their password was echoed back
|
||
|
|
to them. Passwords don't normally echo. The problem is caused by the
|
||
|
|
fact that most applications print out the "Password" prompt and then
|
||
|
|
turn off stdin echo, but if you send your password before the
|
||
|
|
application turned off echo, then you get your password echoed.
|
||
|
|
Normally this wouldn't be a problem when interacting with a human at a
|
||
|
|
real keyboard. If you introduce a slight delay just before writing then
|
||
|
|
this seems to clear up the problem. This was such a common problem for
|
||
|
|
many users that I decided that the default pexpect behavior should be
|
||
|
|
to sleep just before writing to the child application. 1/20th of a
|
||
|
|
second (50 ms) seems to be enough to clear up the problem. You can set
|
||
|
|
delaybeforesend to None to return to the old behavior.
|
||
|
|
|
||
|
|
Note that spawn is clever about finding commands on your path.
|
||
|
|
It uses the same logic that "which" uses to find executables.
|
||
|
|
|
||
|
|
If you wish to get the exit status of the child you must call the
|
||
|
|
close() method. The exit or signal status of the child will be stored
|
||
|
|
in self.exitstatus or self.signalstatus. If the child exited normally
|
||
|
|
then exitstatus will store the exit return code and signalstatus will
|
||
|
|
be None. If the child was terminated abnormally with a signal then
|
||
|
|
signalstatus will store the signal value and exitstatus will be None::
|
||
|
|
|
||
|
|
child = pexpect.spawn('some_command')
|
||
|
|
child.close()
|
||
|
|
print(child.exitstatus, child.signalstatus)
|
||
|
|
|
||
|
|
If you need more detail you can also read the self.status member which
|
||
|
|
stores the status returned by os.waitpid. You can interpret this using
|
||
|
|
os.WIFEXITED/os.WEXITSTATUS or os.WIFSIGNALED/os.TERMSIG.
|
||
|
|
|
||
|
|
The echo attribute may be set to False to disable echoing of input.
|
||
|
|
As a pseudo-terminal, all input echoed by the "keyboard" (send()
|
||
|
|
or sendline()) will be repeated to output. For many cases, it is
|
||
|
|
not desirable to have echo enabled, and it may be later disabled
|
||
|
|
using setecho(False) followed by waitnoecho(). However, for some
|
||
|
|
platforms such as Solaris, this is not possible, and should be
|
||
|
|
disabled immediately on spawn.
|
||
|
|
|
||
|
|
If preexec_fn is given, it will be called in the child process before
|
||
|
|
launching the given command. This is useful to e.g. reset inherited
|
||
|
|
signal handlers.
|
||
|
|
|
||
|
|
The dimensions attribute specifies the size of the pseudo-terminal as
|
||
|
|
seen by the subprocess, and is specified as a two-entry tuple (rows,
|
||
|
|
columns). If this is unspecified, the defaults in ptyprocess will apply.
|
||
|
|
|
||
|
|
The use_poll attribute enables using select.poll() over select.select()
|
||
|
|
for socket handling. This is handy if your system could have > 1024 fds
|
||
|
|
'''
|
||
|
|
super(spawn, self).__init__(timeout=timeout, maxread=maxread, searchwindowsize=searchwindowsize,
|
||
|
|
logfile=logfile, encoding=encoding, codec_errors=codec_errors)
|
||
|
|
self.STDIN_FILENO = pty.STDIN_FILENO
|
||
|
|
self.STDOUT_FILENO = pty.STDOUT_FILENO
|
||
|
|
self.STDERR_FILENO = pty.STDERR_FILENO
|
||
|
|
self.str_last_chars = 100
|
||
|
|
self.cwd = cwd
|
||
|
|
self.env = env
|
||
|
|
self.echo = echo
|
||
|
|
self.ignore_sighup = ignore_sighup
|
||
|
|
self.__irix_hack = sys.platform.lower().startswith('irix')
|
||
|
|
if command is None:
|
||
|
|
self.command = None
|
||
|
|
self.args = None
|
||
|
|
self.name = '<pexpect factory incomplete>'
|
||
|
|
else:
|
||
|
|
self._spawn(command, args, preexec_fn, dimensions)
|
||
|
|
self.use_poll = use_poll
|
||
|
|
|
||
|
|
def __str__(self):
|
||
|
|
'''This returns a human-readable string that represents the state of
|
||
|
|
the object. '''
|
||
|
|
|
||
|
|
s = []
|
||
|
|
s.append(repr(self))
|
||
|
|
s.append('command: ' + str(self.command))
|
||
|
|
s.append('args: %r' % (self.args,))
|
||
|
|
s.append('buffer (last %s chars): %r' % (self.str_last_chars,self.buffer[-self.str_last_chars:]))
|
||
|
|
s.append('before (last %s chars): %r' % (self.str_last_chars,self.before[-self.str_last_chars:] if self.before else ''))
|
||
|
|
s.append('after: %r' % (self.after,))
|
||
|
|
s.append('match: %r' % (self.match,))
|
||
|
|
s.append('match_index: ' + str(self.match_index))
|
||
|
|
s.append('exitstatus: ' + str(self.exitstatus))
|
||
|
|
if hasattr(self, 'ptyproc'):
|
||
|
|
s.append('flag_eof: ' + str(self.flag_eof))
|
||
|
|
s.append('pid: ' + str(self.pid))
|
||
|
|
s.append('child_fd: ' + str(self.child_fd))
|
||
|
|
s.append('closed: ' + str(self.closed))
|
||
|
|
s.append('timeout: ' + str(self.timeout))
|
||
|
|
s.append('delimiter: ' + str(self.delimiter))
|
||
|
|
s.append('logfile: ' + str(self.logfile))
|
||
|
|
s.append('logfile_read: ' + str(self.logfile_read))
|
||
|
|
s.append('logfile_send: ' + str(self.logfile_send))
|
||
|
|
s.append('maxread: ' + str(self.maxread))
|
||
|
|
s.append('ignorecase: ' + str(self.ignorecase))
|
||
|
|
s.append('searchwindowsize: ' + str(self.searchwindowsize))
|
||
|
|
s.append('delaybeforesend: ' + str(self.delaybeforesend))
|
||
|
|
s.append('delayafterclose: ' + str(self.delayafterclose))
|
||
|
|
s.append('delayafterterminate: ' + str(self.delayafterterminate))
|
||
|
|
return '\n'.join(s)
|
||
|
|
|
||
|
|
def _spawn(self, command, args=[], preexec_fn=None, dimensions=None):
|
||
|
|
'''This starts the given command in a child process. This does all the
|
||
|
|
fork/exec type of stuff for a pty. This is called by __init__. If args
|
||
|
|
is empty then command will be parsed (split on spaces) and args will be
|
||
|
|
set to parsed arguments. '''
|
||
|
|
|
||
|
|
# The pid and child_fd of this object get set by this method.
|
||
|
|
# Note that it is difficult for this method to fail.
|
||
|
|
# You cannot detect if the child process cannot start.
|
||
|
|
# So the only way you can tell if the child process started
|
||
|
|
# or not is to try to read from the file descriptor. If you get
|
||
|
|
# EOF immediately then it means that the child is already dead.
|
||
|
|
# That may not necessarily be bad because you may have spawned a child
|
||
|
|
# that performs some task; creates no stdout output; and then dies.
|
||
|
|
|
||
|
|
# If command is an int type then it may represent a file descriptor.
|
||
|
|
if isinstance(command, type(0)):
|
||
|
|
raise ExceptionPexpect('Command is an int type. ' +
|
||
|
|
'If this is a file descriptor then maybe you want to ' +
|
||
|
|
'use fdpexpect.fdspawn which takes an existing ' +
|
||
|
|
'file descriptor instead of a command string.')
|
||
|
|
|
||
|
|
if not isinstance(args, type([])):
|
||
|
|
raise TypeError('The argument, args, must be a list.')
|
||
|
|
|
||
|
|
if args == []:
|
||
|
|
self.args = split_command_line(command)
|
||
|
|
self.command = self.args[0]
|
||
|
|
else:
|
||
|
|
# Make a shallow copy of the args list.
|
||
|
|
self.args = args[:]
|
||
|
|
self.args.insert(0, command)
|
||
|
|
self.command = command
|
||
|
|
|
||
|
|
command_with_path = which(self.command, env=self.env)
|
||
|
|
if command_with_path is None:
|
||
|
|
raise ExceptionPexpect('The command was not found or was not ' +
|
||
|
|
'executable: %s.' % self.command)
|
||
|
|
self.command = command_with_path
|
||
|
|
self.args[0] = self.command
|
||
|
|
|
||
|
|
self.name = '<' + ' '.join(self.args) + '>'
|
||
|
|
|
||
|
|
assert self.pid is None, 'The pid member must be None.'
|
||
|
|
assert self.command is not None, 'The command member must not be None.'
|
||
|
|
|
||
|
|
kwargs = {'echo': self.echo, 'preexec_fn': preexec_fn}
|
||
|
|
if self.ignore_sighup:
|
||
|
|
def preexec_wrapper():
|
||
|
|
"Set SIGHUP to be ignored, then call the real preexec_fn"
|
||
|
|
signal.signal(signal.SIGHUP, signal.SIG_IGN)
|
||
|
|
if preexec_fn is not None:
|
||
|
|
preexec_fn()
|
||
|
|
kwargs['preexec_fn'] = preexec_wrapper
|
||
|
|
|
||
|
|
if dimensions is not None:
|
||
|
|
kwargs['dimensions'] = dimensions
|
||
|
|
|
||
|
|
if self.encoding is not None:
|
||
|
|
# Encode command line using the specified encoding
|
||
|
|
self.args = [a if isinstance(a, bytes) else a.encode(self.encoding)
|
||
|
|
for a in self.args]
|
||
|
|
|
||
|
|
self.ptyproc = self._spawnpty(self.args, env=self.env,
|
||
|
|
cwd=self.cwd, **kwargs)
|
||
|
|
|
||
|
|
self.pid = self.ptyproc.pid
|
||
|
|
self.child_fd = self.ptyproc.fd
|
||
|
|
|
||
|
|
|
||
|
|
self.terminated = False
|
||
|
|
self.closed = False
|
||
|
|
|
||
|
|
def _spawnpty(self, args, **kwargs):
|
||
|
|
'''Spawn a pty and return an instance of PtyProcess.'''
|
||
|
|
return ptyprocess.PtyProcess.spawn(args, **kwargs)
|
||
|
|
|
||
|
|
def close(self, force=True):
|
||
|
|
'''This closes the connection with the child application. Note that
|
||
|
|
calling close() more than once is valid. This emulates standard Python
|
||
|
|
behavior with files. Set force to True if you want to make sure that
|
||
|
|
the child is terminated (SIGKILL is sent if the child ignores SIGHUP
|
||
|
|
and SIGINT). '''
|
||
|
|
|
||
|
|
self.flush()
|
||
|
|
with _wrap_ptyprocess_err():
|
||
|
|
# PtyProcessError may be raised if it is not possible to terminate
|
||
|
|
# the child.
|
||
|
|
self.ptyproc.close(force=force)
|
||
|
|
self.isalive() # Update exit status from ptyproc
|
||
|
|
self.child_fd = -1
|
||
|
|
self.closed = True
|
||
|
|
|
||
|
|
def isatty(self):
|
||
|
|
'''This returns True if the file descriptor is open and connected to a
|
||
|
|
tty(-like) device, else False.
|
||
|
|
|
||
|
|
On SVR4-style platforms implementing streams, such as SunOS and HP-UX,
|
||
|
|
the child pty may not appear as a terminal device. This means
|
||
|
|
methods such as setecho(), setwinsize(), getwinsize() may raise an
|
||
|
|
IOError. '''
|
||
|
|
|
||
|
|
return os.isatty(self.child_fd)
|
||
|
|
|
||
|
|
def waitnoecho(self, timeout=-1):
|
||
|
|
'''This waits until the terminal ECHO flag is set False. This returns
|
||
|
|
True if the echo mode is off. This returns False if the ECHO flag was
|
||
|
|
not set False before the timeout. This can be used to detect when the
|
||
|
|
child is waiting for a password. Usually a child application will turn
|
||
|
|
off echo mode when it is waiting for the user to enter a password. For
|
||
|
|
example, instead of expecting the "password:" prompt you can wait for
|
||
|
|
the child to set ECHO off::
|
||
|
|
|
||
|
|
p = pexpect.spawn('ssh user@example.com')
|
||
|
|
p.waitnoecho()
|
||
|
|
p.sendline(mypassword)
|
||
|
|
|
||
|
|
If timeout==-1 then this method will use the value in self.timeout.
|
||
|
|
If timeout==None then this method to block until ECHO flag is False.
|
||
|
|
'''
|
||
|
|
|
||
|
|
if timeout == -1:
|
||
|
|
timeout = self.timeout
|
||
|
|
if timeout is not None:
|
||
|
|
end_time = time.time() + timeout
|
||
|
|
while True:
|
||
|
|
if not self.getecho():
|
||
|
|
return True
|
||
|
|
if timeout < 0 and timeout is not None:
|
||
|
|
return False
|
||
|
|
if timeout is not None:
|
||
|
|
timeout = end_time - time.time()
|
||
|
|
time.sleep(0.1)
|
||
|
|
|
||
|
|
def getecho(self):
|
||
|
|
'''This returns the terminal echo mode. This returns True if echo is
|
||
|
|
on or False if echo is off. Child applications that are expecting you
|
||
|
|
to enter a password often set ECHO False. See waitnoecho().
|
||
|
|
|
||
|
|
Not supported on platforms where ``isatty()`` returns False. '''
|
||
|
|
return self.ptyproc.getecho()
|
||
|
|
|
||
|
|
def setecho(self, state):
|
||
|
|
'''This sets the terminal echo mode on or off. Note that anything the
|
||
|
|
child sent before the echo will be lost, so you should be sure that
|
||
|
|
your input buffer is empty before you call setecho(). For example, the
|
||
|
|
following will work as expected::
|
||
|
|
|
||
|
|
p = pexpect.spawn('cat') # Echo is on by default.
|
||
|
|
p.sendline('1234') # We expect see this twice from the child...
|
||
|
|
p.expect(['1234']) # ... once from the tty echo...
|
||
|
|
p.expect(['1234']) # ... and again from cat itself.
|
||
|
|
p.setecho(False) # Turn off tty echo
|
||
|
|
p.sendline('abcd') # We will set this only once (echoed by cat).
|
||
|
|
p.sendline('wxyz') # We will set this only once (echoed by cat)
|
||
|
|
p.expect(['abcd'])
|
||
|
|
p.expect(['wxyz'])
|
||
|
|
|
||
|
|
The following WILL NOT WORK because the lines sent before the setecho
|
||
|
|
will be lost::
|
||
|
|
|
||
|
|
p = pexpect.spawn('cat')
|
||
|
|
p.sendline('1234')
|
||
|
|
p.setecho(False) # Turn off tty echo
|
||
|
|
p.sendline('abcd') # We will set this only once (echoed by cat).
|
||
|
|
p.sendline('wxyz') # We will set this only once (echoed by cat)
|
||
|
|
p.expect(['1234'])
|
||
|
|
p.expect(['1234'])
|
||
|
|
p.expect(['abcd'])
|
||
|
|
p.expect(['wxyz'])
|
||
|
|
|
||
|
|
|
||
|
|
Not supported on platforms where ``isatty()`` returns False.
|
||
|
|
'''
|
||
|
|
return self.ptyproc.setecho(state)
|
||
|
|
|
||
|
|
def read_nonblocking(self, size=1, timeout=-1):
|
||
|
|
'''This reads at most size characters from the child application. It
|
||
|
|
includes a timeout. If the read does not complete within the timeout
|
||
|
|
period then a TIMEOUT exception is raised. If the end of file is read
|
||
|
|
then an EOF exception will be raised. If a logfile is specified, a
|
||
|
|
copy is written to that log.
|
||
|
|
|
||
|
|
If timeout is None then the read may block indefinitely.
|
||
|
|
If timeout is -1 then the self.timeout value is used. If timeout is 0
|
||
|
|
then the child is polled and if there is no data immediately ready
|
||
|
|
then this will raise a TIMEOUT exception.
|
||
|
|
|
||
|
|
The timeout refers only to the amount of time to read at least one
|
||
|
|
character. This is not affected by the 'size' parameter, so if you call
|
||
|
|
read_nonblocking(size=100, timeout=30) and only one character is
|
||
|
|
available right away then one character will be returned immediately.
|
||
|
|
It will not wait for 30 seconds for another 99 characters to come in.
|
||
|
|
|
||
|
|
On the other hand, if there are bytes available to read immediately,
|
||
|
|
all those bytes will be read (up to the buffer size). So, if the
|
||
|
|
buffer size is 1 megabyte and there is 1 megabyte of data available
|
||
|
|
to read, the buffer will be filled, regardless of timeout.
|
||
|
|
|
||
|
|
This is a wrapper around os.read(). It uses select.select() or
|
||
|
|
select.poll() to implement the timeout. '''
|
||
|
|
|
||
|
|
if self.closed:
|
||
|
|
raise ValueError('I/O operation on closed file.')
|
||
|
|
|
||
|
|
if self.use_poll:
|
||
|
|
def select(timeout):
|
||
|
|
return poll_ignore_interrupts([self.child_fd], timeout)
|
||
|
|
else:
|
||
|
|
def select(timeout):
|
||
|
|
return select_ignore_interrupts([self.child_fd], [], [], timeout)[0]
|
||
|
|
|
||
|
|
# If there is data available to read right now, read as much as
|
||
|
|
# we can. We do this to increase performance if there are a lot
|
||
|
|
# of bytes to be read. This also avoids calling isalive() too
|
||
|
|
# often. See also:
|
||
|
|
# * https://github.com/pexpect/pexpect/pull/304
|
||
|
|
# * http://trac.sagemath.org/ticket/10295
|
||
|
|
if select(0):
|
||
|
|
try:
|
||
|
|
incoming = super(spawn, self).read_nonblocking(size)
|
||
|
|
except EOF:
|
||
|
|
# Maybe the child is dead: update some attributes in that case
|
||
|
|
self.isalive()
|
||
|
|
raise
|
||
|
|
while len(incoming) < size and select(0):
|
||
|
|
try:
|
||
|
|
incoming += super(spawn, self).read_nonblocking(size - len(incoming))
|
||
|
|
except EOF:
|
||
|
|
# Maybe the child is dead: update some attributes in that case
|
||
|
|
self.isalive()
|
||
|
|
# Don't raise EOF, just return what we read so far.
|
||
|
|
return incoming
|
||
|
|
return incoming
|
||
|
|
|
||
|
|
if timeout == -1:
|
||
|
|
timeout = self.timeout
|
||
|
|
|
||
|
|
if not self.isalive():
|
||
|
|
# The process is dead, but there may or may not be data
|
||
|
|
# available to read. Note that some systems such as Solaris
|
||
|
|
# do not give an EOF when the child dies. In fact, you can
|
||
|
|
# still try to read from the child_fd -- it will block
|
||
|
|
# forever or until TIMEOUT. For that reason, it's important
|
||
|
|
# to do this check before calling select() with timeout.
|
||
|
|
if select(0):
|
||
|
|
return super(spawn, self).read_nonblocking(size)
|
||
|
|
self.flag_eof = True
|
||
|
|
raise EOF('End Of File (EOF). Braindead platform.')
|
||
|
|
elif self.__irix_hack:
|
||
|
|
# Irix takes a long time before it realizes a child was terminated.
|
||
|
|
# Make sure that the timeout is at least 2 seconds.
|
||
|
|
# FIXME So does this mean Irix systems are forced to always have
|
||
|
|
# FIXME a 2 second delay when calling read_nonblocking? That sucks.
|
||
|
|
if timeout is not None and timeout < 2:
|
||
|
|
timeout = 2
|
||
|
|
|
||
|
|
# Because of the select(0) check above, we know that no data
|
||
|
|
# is available right now. But if a non-zero timeout is given
|
||
|
|
# (possibly timeout=None), we call select() with a timeout.
|
||
|
|
if (timeout != 0) and select(timeout):
|
||
|
|
return super(spawn, self).read_nonblocking(size)
|
||
|
|
|
||
|
|
if not self.isalive():
|
||
|
|
# Some platforms, such as Irix, will claim that their
|
||
|
|
# processes are alive; timeout on the select; and
|
||
|
|
# then finally admit that they are not alive.
|
||
|
|
self.flag_eof = True
|
||
|
|
raise EOF('End of File (EOF). Very slow platform.')
|
||
|
|
else:
|
||
|
|
raise TIMEOUT('Timeout exceeded.')
|
||
|
|
|
||
|
|
def write(self, s):
|
||
|
|
'''This is similar to send() except that there is no return value.
|
||
|
|
'''
|
||
|
|
|
||
|
|
self.send(s)
|
||
|
|
|
||
|
|
def writelines(self, sequence):
|
||
|
|
'''This calls write() for each element in the sequence. The sequence
|
||
|
|
can be any iterable object producing strings, typically a list of
|
||
|
|
strings. This does not add line separators. There is no return value.
|
||
|
|
'''
|
||
|
|
|
||
|
|
for s in sequence:
|
||
|
|
self.write(s)
|
||
|
|
|
||
|
|
def send(self, s):
|
||
|
|
'''Sends string ``s`` to the child process, returning the number of
|
||
|
|
bytes written. If a logfile is specified, a copy is written to that
|
||
|
|
log.
|
||
|
|
|
||
|
|
The default terminal input mode is canonical processing unless set
|
||
|
|
otherwise by the child process. This allows backspace and other line
|
||
|
|
processing to be performed prior to transmitting to the receiving
|
||
|
|
program. As this is buffered, there is a limited size of such buffer.
|
||
|
|
|
||
|
|
On Linux systems, this is 4096 (defined by N_TTY_BUF_SIZE). All
|
||
|
|
other systems honor the POSIX.1 definition PC_MAX_CANON -- 1024
|
||
|
|
on OSX, 256 on OpenSolaris, and 1920 on FreeBSD.
|
||
|
|
|
||
|
|
This value may be discovered using fpathconf(3)::
|
||
|
|
|
||
|
|
>>> from os import fpathconf
|
||
|
|
>>> print(fpathconf(0, 'PC_MAX_CANON'))
|
||
|
|
256
|
||
|
|
|
||
|
|
On such a system, only 256 bytes may be received per line. Any
|
||
|
|
subsequent bytes received will be discarded. BEL (``'\a'``) is then
|
||
|
|
sent to output if IMAXBEL (termios.h) is set by the tty driver.
|
||
|
|
This is usually enabled by default. Linux does not honor this as
|
||
|
|
an option -- it behaves as though it is always set on.
|
||
|
|
|
||
|
|
Canonical input processing may be disabled altogether by executing
|
||
|
|
a shell, then stty(1), before executing the final program::
|
||
|
|
|
||
|
|
>>> bash = pexpect.spawn('/bin/bash', echo=False)
|
||
|
|
>>> bash.sendline('stty -icanon')
|
||
|
|
>>> bash.sendline('base64')
|
||
|
|
>>> bash.sendline('x' * 5000)
|
||
|
|
'''
|
||
|
|
|
||
|
|
if self.delaybeforesend is not None:
|
||
|
|
time.sleep(self.delaybeforesend)
|
||
|
|
|
||
|
|
s = self._coerce_send_string(s)
|
||
|
|
self._log(s, 'send')
|
||
|
|
|
||
|
|
b = self._encoder.encode(s, final=False)
|
||
|
|
return os.write(self.child_fd, b)
|
||
|
|
|
||
|
|
def sendline(self, s=''):
|
||
|
|
'''Wraps send(), sending string ``s`` to child process, with
|
||
|
|
``os.linesep`` automatically appended. Returns number of bytes
|
||
|
|
written. Only a limited number of bytes may be sent for each
|
||
|
|
line in the default terminal mode, see docstring of :meth:`send`.
|
||
|
|
'''
|
||
|
|
s = self._coerce_send_string(s)
|
||
|
|
return self.send(s + self.linesep)
|
||
|
|
|
||
|
|
def _log_control(self, s):
|
||
|
|
"""Write control characters to the appropriate log files"""
|
||
|
|
if self.encoding is not None:
|
||
|
|
s = s.decode(self.encoding, 'replace')
|
||
|
|
self._log(s, 'send')
|
||
|
|
|
||
|
|
def sendcontrol(self, char):
|
||
|
|
'''Helper method that wraps send() with mnemonic access for sending control
|
||
|
|
character to the child (such as Ctrl-C or Ctrl-D). For example, to send
|
||
|
|
Ctrl-G (ASCII 7, bell, '\a')::
|
||
|
|
|
||
|
|
child.sendcontrol('g')
|
||
|
|
|
||
|
|
See also, sendintr() and sendeof().
|
||
|
|
'''
|
||
|
|
n, byte = self.ptyproc.sendcontrol(char)
|
||
|
|
self._log_control(byte)
|
||
|
|
return n
|
||
|
|
|
||
|
|
def sendeof(self):
|
||
|
|
'''This sends an EOF to the child. This sends a character which causes
|
||
|
|
the pending parent output buffer to be sent to the waiting child
|
||
|
|
program without waiting for end-of-line. If it is the first character
|
||
|
|
of the line, the read() in the user program returns 0, which signifies
|
||
|
|
end-of-file. This means to work as expected a sendeof() has to be
|
||
|
|
called at the beginning of a line. This method does not send a newline.
|
||
|
|
It is the responsibility of the caller to ensure the eof is sent at the
|
||
|
|
beginning of a line. '''
|
||
|
|
|
||
|
|
n, byte = self.ptyproc.sendeof()
|
||
|
|
self._log_control(byte)
|
||
|
|
|
||
|
|
def sendintr(self):
|
||
|
|
'''This sends a SIGINT to the child. It does not require
|
||
|
|
the SIGINT to be the first character on a line. '''
|
||
|
|
|
||
|
|
n, byte = self.ptyproc.sendintr()
|
||
|
|
self._log_control(byte)
|
||
|
|
|
||
|
|
@property
|
||
|
|
def flag_eof(self):
|
||
|
|
return self.ptyproc.flag_eof
|
||
|
|
|
||
|
|
@flag_eof.setter
|
||
|
|
def flag_eof(self, value):
|
||
|
|
self.ptyproc.flag_eof = value
|
||
|
|
|
||
|
|
def eof(self):
|
||
|
|
'''This returns True if the EOF exception was ever raised.
|
||
|
|
'''
|
||
|
|
return self.flag_eof
|
||
|
|
|
||
|
|
def terminate(self, force=False):
|
||
|
|
'''This forces a child process to terminate. It starts nicely with
|
||
|
|
SIGHUP and SIGINT. If "force" is True then moves onto SIGKILL. This
|
||
|
|
returns True if the child was terminated. This returns False if the
|
||
|
|
child could not be terminated. '''
|
||
|
|
|
||
|
|
if not self.isalive():
|
||
|
|
return True
|
||
|
|
try:
|
||
|
|
self.kill(signal.SIGHUP)
|
||
|
|
time.sleep(self.delayafterterminate)
|
||
|
|
if not self.isalive():
|
||
|
|
return True
|
||
|
|
self.kill(signal.SIGCONT)
|
||
|
|
time.sleep(self.delayafterterminate)
|
||
|
|
if not self.isalive():
|
||
|
|
return True
|
||
|
|
self.kill(signal.SIGINT)
|
||
|
|
time.sleep(self.delayafterterminate)
|
||
|
|
if not self.isalive():
|
||
|
|
return True
|
||
|
|
if force:
|
||
|
|
self.kill(signal.SIGKILL)
|
||
|
|
time.sleep(self.delayafterterminate)
|
||
|
|
if not self.isalive():
|
||
|
|
return True
|
||
|
|
else:
|
||
|
|
return False
|
||
|
|
return False
|
||
|
|
except OSError:
|
||
|
|
# I think there are kernel timing issues that sometimes cause
|
||
|
|
# this to happen. I think isalive() reports True, but the
|
||
|
|
# process is dead to the kernel.
|
||
|
|
# Make one last attempt to see if the kernel is up to date.
|
||
|
|
time.sleep(self.delayafterterminate)
|
||
|
|
if not self.isalive():
|
||
|
|
return True
|
||
|
|
else:
|
||
|
|
return False
|
||
|
|
|
||
|
|
def wait(self):
|
||
|
|
'''This waits until the child exits. This is a blocking call. This will
|
||
|
|
not read any data from the child, so this will block forever if the
|
||
|
|
child has unread output and has terminated. In other words, the child
|
||
|
|
may have printed output then called exit(), but, the child is
|
||
|
|
technically still alive until its output is read by the parent.
|
||
|
|
|
||
|
|
This method is non-blocking if :meth:`wait` has already been called
|
||
|
|
previously or :meth:`isalive` method returns False. It simply returns
|
||
|
|
the previously determined exit status.
|
||
|
|
'''
|
||
|
|
|
||
|
|
ptyproc = self.ptyproc
|
||
|
|
with _wrap_ptyprocess_err():
|
||
|
|
# exception may occur if "Is some other process attempting
|
||
|
|
# "job control with our child pid?"
|
||
|
|
exitstatus = ptyproc.wait()
|
||
|
|
self.status = ptyproc.status
|
||
|
|
self.exitstatus = ptyproc.exitstatus
|
||
|
|
self.signalstatus = ptyproc.signalstatus
|
||
|
|
self.terminated = True
|
||
|
|
|
||
|
|
return exitstatus
|
||
|
|
|
||
|
|
def isalive(self):
|
||
|
|
'''This tests if the child process is running or not. This is
|
||
|
|
non-blocking. If the child was terminated then this will read the
|
||
|
|
exitstatus or signalstatus of the child. This returns True if the child
|
||
|
|
process appears to be running or False if not. It can take literally
|
||
|
|
SECONDS for Solaris to return the right status. '''
|
||
|
|
|
||
|
|
ptyproc = self.ptyproc
|
||
|
|
with _wrap_ptyprocess_err():
|
||
|
|
alive = ptyproc.isalive()
|
||
|
|
|
||
|
|
if not alive:
|
||
|
|
self.status = ptyproc.status
|
||
|
|
self.exitstatus = ptyproc.exitstatus
|
||
|
|
self.signalstatus = ptyproc.signalstatus
|
||
|
|
self.terminated = True
|
||
|
|
|
||
|
|
return alive
|
||
|
|
|
||
|
|
def kill(self, sig):
|
||
|
|
|
||
|
|
'''This sends the given signal to the child application. In keeping
|
||
|
|
with UNIX tradition it has a misleading name. It does not necessarily
|
||
|
|
kill the child unless you send the right signal. '''
|
||
|
|
|
||
|
|
# Same as os.kill, but the pid is given for you.
|
||
|
|
if self.isalive():
|
||
|
|
os.kill(self.pid, sig)
|
||
|
|
|
||
|
|
def getwinsize(self):
|
||
|
|
'''This returns the terminal window size of the child tty. The return
|
||
|
|
value is a tuple of (rows, cols). '''
|
||
|
|
return self.ptyproc.getwinsize()
|
||
|
|
|
||
|
|
def setwinsize(self, rows, cols):
|
||
|
|
'''This sets the terminal window size of the child tty. This will cause
|
||
|
|
a SIGWINCH signal to be sent to the child. This does not change the
|
||
|
|
physical window size. It changes the size reported to TTY-aware
|
||
|
|
applications like vi or curses -- applications that respond to the
|
||
|
|
SIGWINCH signal. '''
|
||
|
|
return self.ptyproc.setwinsize(rows, cols)
|
||
|
|
|
||
|
|
|
||
|
|
def interact(self, escape_character=chr(29),
|
||
|
|
input_filter=None, output_filter=None):
|
||
|
|
|
||
|
|
'''This gives control of the child process to the interactive user (the
|
||
|
|
human at the keyboard). Keystrokes are sent to the child process, and
|
||
|
|
the stdout and stderr output of the child process is printed. This
|
||
|
|
simply echos the child stdout and child stderr to the real stdout and
|
||
|
|
it echos the real stdin to the child stdin. When the user types the
|
||
|
|
escape_character this method will return None. The escape_character
|
||
|
|
will not be transmitted. The default for escape_character is
|
||
|
|
entered as ``Ctrl - ]``, the very same as BSD telnet. To prevent
|
||
|
|
escaping, escape_character may be set to None.
|
||
|
|
|
||
|
|
If a logfile is specified, then the data sent and received from the
|
||
|
|
child process in interact mode is duplicated to the given log.
|
||
|
|
|
||
|
|
You may pass in optional input and output filter functions. These
|
||
|
|
functions should take bytes array and return bytes array too. Even
|
||
|
|
with ``encoding='utf-8'`` support, meth:`interact` will always pass
|
||
|
|
input_filter and output_filter bytes. You may need to wrap your
|
||
|
|
function to decode and encode back to UTF-8.
|
||
|
|
|
||
|
|
The output_filter will be passed all the output from the child process.
|
||
|
|
The input_filter will be passed all the keyboard input from the user.
|
||
|
|
The input_filter is run BEFORE the check for the escape_character.
|
||
|
|
|
||
|
|
Note that if you change the window size of the parent the SIGWINCH
|
||
|
|
signal will not be passed through to the child. If you want the child
|
||
|
|
window size to change when the parent's window size changes then do
|
||
|
|
something like the following example::
|
||
|
|
|
||
|
|
import pexpect, struct, fcntl, termios, signal, sys
|
||
|
|
def sigwinch_passthrough (sig, data):
|
||
|
|
s = struct.pack("HHHH", 0, 0, 0, 0)
|
||
|
|
a = struct.unpack('hhhh', fcntl.ioctl(sys.stdout.fileno(),
|
||
|
|
termios.TIOCGWINSZ , s))
|
||
|
|
if not p.closed:
|
||
|
|
p.setwinsize(a[0],a[1])
|
||
|
|
|
||
|
|
# Note this 'p' is global and used in sigwinch_passthrough.
|
||
|
|
p = pexpect.spawn('/bin/bash')
|
||
|
|
signal.signal(signal.SIGWINCH, sigwinch_passthrough)
|
||
|
|
p.interact()
|
||
|
|
'''
|
||
|
|
|
||
|
|
# Flush the buffer.
|
||
|
|
self.write_to_stdout(self.buffer)
|
||
|
|
self.stdout.flush()
|
||
|
|
self._buffer = self.buffer_type()
|
||
|
|
mode = tty.tcgetattr(self.STDIN_FILENO)
|
||
|
|
tty.setraw(self.STDIN_FILENO)
|
||
|
|
if escape_character is not None and PY3:
|
||
|
|
escape_character = escape_character.encode('latin-1')
|
||
|
|
try:
|
||
|
|
self.__interact_copy(escape_character, input_filter, output_filter)
|
||
|
|
finally:
|
||
|
|
tty.tcsetattr(self.STDIN_FILENO, tty.TCSAFLUSH, mode)
|
||
|
|
|
||
|
|
def __interact_writen(self, fd, data):
|
||
|
|
'''This is used by the interact() method.
|
||
|
|
'''
|
||
|
|
|
||
|
|
while data != b'' and self.isalive():
|
||
|
|
n = os.write(fd, data)
|
||
|
|
data = data[n:]
|
||
|
|
|
||
|
|
def __interact_read(self, fd):
|
||
|
|
'''This is used by the interact() method.
|
||
|
|
'''
|
||
|
|
|
||
|
|
return os.read(fd, 1000)
|
||
|
|
|
||
|
|
def __interact_copy(
|
||
|
|
self, escape_character=None, input_filter=None, output_filter=None
|
||
|
|
):
|
||
|
|
|
||
|
|
'''This is used by the interact() method.
|
||
|
|
'''
|
||
|
|
|
||
|
|
while self.isalive():
|
||
|
|
if self.use_poll:
|
||
|
|
r = poll_ignore_interrupts([self.child_fd, self.STDIN_FILENO])
|
||
|
|
else:
|
||
|
|
r, w, e = select_ignore_interrupts(
|
||
|
|
[self.child_fd, self.STDIN_FILENO], [], []
|
||
|
|
)
|
||
|
|
if self.child_fd in r:
|
||
|
|
try:
|
||
|
|
data = self.__interact_read(self.child_fd)
|
||
|
|
except OSError as err:
|
||
|
|
if err.args[0] == errno.EIO:
|
||
|
|
# Linux-style EOF
|
||
|
|
break
|
||
|
|
raise
|
||
|
|
if data == b'':
|
||
|
|
# BSD-style EOF
|
||
|
|
break
|
||
|
|
if output_filter:
|
||
|
|
data = output_filter(data)
|
||
|
|
self._log(data, 'read')
|
||
|
|
os.write(self.STDOUT_FILENO, data)
|
||
|
|
if self.STDIN_FILENO in r:
|
||
|
|
data = self.__interact_read(self.STDIN_FILENO)
|
||
|
|
if input_filter:
|
||
|
|
data = input_filter(data)
|
||
|
|
i = -1
|
||
|
|
if escape_character is not None:
|
||
|
|
i = data.rfind(escape_character)
|
||
|
|
if i != -1:
|
||
|
|
data = data[:i]
|
||
|
|
if data:
|
||
|
|
self._log(data, 'send')
|
||
|
|
self.__interact_writen(self.child_fd, data)
|
||
|
|
break
|
||
|
|
self._log(data, 'send')
|
||
|
|
self.__interact_writen(self.child_fd, data)
|
||
|
|
|
||
|
|
|
||
|
|
def spawnu(*args, **kwargs):
|
||
|
|
"""Deprecated: pass encoding to spawn() instead."""
|
||
|
|
kwargs.setdefault('encoding', 'utf-8')
|
||
|
|
return spawn(*args, **kwargs)
|