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861 lines
36 KiB
Python
861 lines
36 KiB
Python
import os
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import sys
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import time
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import pty
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import tty
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import errno
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import signal
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from contextlib import contextmanager
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import ptyprocess
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from ptyprocess.ptyprocess import use_native_pty_fork
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from .exceptions import ExceptionPexpect, EOF, TIMEOUT
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from .spawnbase import SpawnBase
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from .utils import (
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which, split_command_line, select_ignore_interrupts, poll_ignore_interrupts
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)
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@contextmanager
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def _wrap_ptyprocess_err():
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"""Turn ptyprocess errors into our own ExceptionPexpect errors"""
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try:
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yield
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except ptyprocess.PtyProcessError as e:
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raise ExceptionPexpect(*e.args)
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PY3 = (sys.version_info[0] >= 3)
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class spawn(SpawnBase):
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'''This is the main class interface for Pexpect. Use this class to start
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and control child applications. '''
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# This is purely informational now - changing it has no effect
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use_native_pty_fork = use_native_pty_fork
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def __init__(self, command, args=[], timeout=30, maxread=2000,
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searchwindowsize=None, logfile=None, cwd=None, env=None,
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ignore_sighup=False, echo=True, preexec_fn=None,
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encoding=None, codec_errors='strict', dimensions=None,
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use_poll=False):
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'''This is the constructor. The command parameter may be a string that
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includes a command and any arguments to the command. For example::
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child = pexpect.spawn('/usr/bin/ftp')
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child = pexpect.spawn('/usr/bin/ssh user@example.com')
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child = pexpect.spawn('ls -latr /tmp')
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You may also construct it with a list of arguments like so::
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child = pexpect.spawn('/usr/bin/ftp', [])
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child = pexpect.spawn('/usr/bin/ssh', ['user@example.com'])
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child = pexpect.spawn('ls', ['-latr', '/tmp'])
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After this the child application will be created and will be ready to
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talk to. For normal use, see expect() and send() and sendline().
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Remember that Pexpect does NOT interpret shell meta characters such as
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redirect, pipe, or wild cards (``>``, ``|``, or ``*``). This is a
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common mistake. If you want to run a command and pipe it through
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another command then you must also start a shell. For example::
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child = pexpect.spawn('/bin/bash -c "ls -l | grep LOG > logs.txt"')
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child.expect(pexpect.EOF)
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The second form of spawn (where you pass a list of arguments) is useful
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in situations where you wish to spawn a command and pass it its own
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argument list. This can make syntax more clear. For example, the
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following is equivalent to the previous example::
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shell_cmd = 'ls -l | grep LOG > logs.txt'
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child = pexpect.spawn('/bin/bash', ['-c', shell_cmd])
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child.expect(pexpect.EOF)
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The maxread attribute sets the read buffer size. This is maximum number
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of bytes that Pexpect will try to read from a TTY at one time. Setting
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the maxread size to 1 will turn off buffering. Setting the maxread
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value higher may help performance in cases where large amounts of
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output are read back from the child. This feature is useful in
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conjunction with searchwindowsize.
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When the keyword argument *searchwindowsize* is None (default), the
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full buffer is searched at each iteration of receiving incoming data.
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The default number of bytes scanned at each iteration is very large
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and may be reduced to collaterally reduce search cost. After
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:meth:`~.expect` returns, the full buffer attribute remains up to
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size *maxread* irrespective of *searchwindowsize* value.
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When the keyword argument ``timeout`` is specified as a number,
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(default: *30*), then :class:`TIMEOUT` will be raised after the value
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specified has elapsed, in seconds, for any of the :meth:`~.expect`
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family of method calls. When None, TIMEOUT will not be raised, and
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:meth:`~.expect` may block indefinitely until match.
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The logfile member turns on or off logging. All input and output will
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be copied to the given file object. Set logfile to None to stop
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logging. This is the default. Set logfile to sys.stdout to echo
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everything to standard output. The logfile is flushed after each write.
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Example log input and output to a file::
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child = pexpect.spawn('some_command')
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fout = open('mylog.txt','wb')
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child.logfile = fout
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Example log to stdout::
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# In Python 2:
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child = pexpect.spawn('some_command')
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child.logfile = sys.stdout
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# In Python 3, we'll use the ``encoding`` argument to decode data
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# from the subprocess and handle it as unicode:
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child = pexpect.spawn('some_command', encoding='utf-8')
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child.logfile = sys.stdout
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The logfile_read and logfile_send members can be used to separately log
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the input from the child and output sent to the child. Sometimes you
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don't want to see everything you write to the child. You only want to
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log what the child sends back. For example::
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child = pexpect.spawn('some_command')
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child.logfile_read = sys.stdout
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You will need to pass an encoding to spawn in the above code if you are
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using Python 3.
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To separately log output sent to the child use logfile_send::
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child.logfile_send = fout
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If ``ignore_sighup`` is True, the child process will ignore SIGHUP
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signals. The default is False from Pexpect 4.0, meaning that SIGHUP
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will be handled normally by the child.
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The delaybeforesend helps overcome a weird behavior that many users
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were experiencing. The typical problem was that a user would expect() a
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"Password:" prompt and then immediately call sendline() to send the
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password. The user would then see that their password was echoed back
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to them. Passwords don't normally echo. The problem is caused by the
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fact that most applications print out the "Password" prompt and then
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turn off stdin echo, but if you send your password before the
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application turned off echo, then you get your password echoed.
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Normally this wouldn't be a problem when interacting with a human at a
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real keyboard. If you introduce a slight delay just before writing then
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this seems to clear up the problem. This was such a common problem for
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many users that I decided that the default pexpect behavior should be
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to sleep just before writing to the child application. 1/20th of a
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second (50 ms) seems to be enough to clear up the problem. You can set
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delaybeforesend to None to return to the old behavior.
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Note that spawn is clever about finding commands on your path.
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It uses the same logic that "which" uses to find executables.
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If you wish to get the exit status of the child you must call the
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close() method. The exit or signal status of the child will be stored
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in self.exitstatus or self.signalstatus. If the child exited normally
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then exitstatus will store the exit return code and signalstatus will
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be None. If the child was terminated abnormally with a signal then
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signalstatus will store the signal value and exitstatus will be None::
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child = pexpect.spawn('some_command')
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child.close()
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print(child.exitstatus, child.signalstatus)
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If you need more detail you can also read the self.status member which
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stores the status returned by os.waitpid. You can interpret this using
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os.WIFEXITED/os.WEXITSTATUS or os.WIFSIGNALED/os.TERMSIG.
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The echo attribute may be set to False to disable echoing of input.
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As a pseudo-terminal, all input echoed by the "keyboard" (send()
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or sendline()) will be repeated to output. For many cases, it is
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not desirable to have echo enabled, and it may be later disabled
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using setecho(False) followed by waitnoecho(). However, for some
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platforms such as Solaris, this is not possible, and should be
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disabled immediately on spawn.
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If preexec_fn is given, it will be called in the child process before
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launching the given command. This is useful to e.g. reset inherited
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signal handlers.
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The dimensions attribute specifies the size of the pseudo-terminal as
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seen by the subprocess, and is specified as a two-entry tuple (rows,
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columns). If this is unspecified, the defaults in ptyprocess will apply.
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The use_poll attribute enables using select.poll() over select.select()
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for socket handling. This is handy if your system could have > 1024 fds
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'''
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super(spawn, self).__init__(timeout=timeout, maxread=maxread, searchwindowsize=searchwindowsize,
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logfile=logfile, encoding=encoding, codec_errors=codec_errors)
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self.STDIN_FILENO = pty.STDIN_FILENO
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self.STDOUT_FILENO = pty.STDOUT_FILENO
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self.STDERR_FILENO = pty.STDERR_FILENO
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self.str_last_chars = 100
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self.cwd = cwd
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self.env = env
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self.echo = echo
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self.ignore_sighup = ignore_sighup
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self.__irix_hack = sys.platform.lower().startswith('irix')
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if command is None:
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self.command = None
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self.args = None
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self.name = '<pexpect factory incomplete>'
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else:
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self._spawn(command, args, preexec_fn, dimensions)
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self.use_poll = use_poll
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def __str__(self):
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'''This returns a human-readable string that represents the state of
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the object. '''
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s = []
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s.append(repr(self))
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s.append('command: ' + str(self.command))
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s.append('args: %r' % (self.args,))
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s.append('buffer (last %s chars): %r' % (self.str_last_chars,self.buffer[-self.str_last_chars:]))
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s.append('before (last %s chars): %r' % (self.str_last_chars,self.before[-self.str_last_chars:] if self.before else ''))
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s.append('after: %r' % (self.after,))
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s.append('match: %r' % (self.match,))
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s.append('match_index: ' + str(self.match_index))
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s.append('exitstatus: ' + str(self.exitstatus))
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if hasattr(self, 'ptyproc'):
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s.append('flag_eof: ' + str(self.flag_eof))
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s.append('pid: ' + str(self.pid))
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s.append('child_fd: ' + str(self.child_fd))
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s.append('closed: ' + str(self.closed))
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s.append('timeout: ' + str(self.timeout))
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s.append('delimiter: ' + str(self.delimiter))
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s.append('logfile: ' + str(self.logfile))
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s.append('logfile_read: ' + str(self.logfile_read))
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s.append('logfile_send: ' + str(self.logfile_send))
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s.append('maxread: ' + str(self.maxread))
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s.append('ignorecase: ' + str(self.ignorecase))
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s.append('searchwindowsize: ' + str(self.searchwindowsize))
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s.append('delaybeforesend: ' + str(self.delaybeforesend))
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s.append('delayafterclose: ' + str(self.delayafterclose))
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s.append('delayafterterminate: ' + str(self.delayafterterminate))
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return '\n'.join(s)
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def _spawn(self, command, args=[], preexec_fn=None, dimensions=None):
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'''This starts the given command in a child process. This does all the
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fork/exec type of stuff for a pty. This is called by __init__. If args
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is empty then command will be parsed (split on spaces) and args will be
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set to parsed arguments. '''
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# The pid and child_fd of this object get set by this method.
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# Note that it is difficult for this method to fail.
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# You cannot detect if the child process cannot start.
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# So the only way you can tell if the child process started
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# or not is to try to read from the file descriptor. If you get
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# EOF immediately then it means that the child is already dead.
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# That may not necessarily be bad because you may have spawned a child
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# that performs some task; creates no stdout output; and then dies.
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# If command is an int type then it may represent a file descriptor.
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if isinstance(command, type(0)):
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raise ExceptionPexpect('Command is an int type. ' +
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'If this is a file descriptor then maybe you want to ' +
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'use fdpexpect.fdspawn which takes an existing ' +
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'file descriptor instead of a command string.')
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if not isinstance(args, type([])):
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raise TypeError('The argument, args, must be a list.')
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if args == []:
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self.args = split_command_line(command)
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self.command = self.args[0]
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else:
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# Make a shallow copy of the args list.
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self.args = args[:]
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self.args.insert(0, command)
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self.command = command
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command_with_path = which(self.command, env=self.env)
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if command_with_path is None:
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raise ExceptionPexpect('The command was not found or was not ' +
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'executable: %s.' % self.command)
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self.command = command_with_path
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self.args[0] = self.command
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self.name = '<' + ' '.join(self.args) + '>'
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assert self.pid is None, 'The pid member must be None.'
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assert self.command is not None, 'The command member must not be None.'
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kwargs = {'echo': self.echo, 'preexec_fn': preexec_fn}
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if self.ignore_sighup:
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def preexec_wrapper():
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"Set SIGHUP to be ignored, then call the real preexec_fn"
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signal.signal(signal.SIGHUP, signal.SIG_IGN)
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if preexec_fn is not None:
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preexec_fn()
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kwargs['preexec_fn'] = preexec_wrapper
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if dimensions is not None:
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kwargs['dimensions'] = dimensions
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if self.encoding is not None:
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# Encode command line using the specified encoding
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self.args = [a if isinstance(a, bytes) else a.encode(self.encoding)
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for a in self.args]
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self.ptyproc = self._spawnpty(self.args, env=self.env,
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cwd=self.cwd, **kwargs)
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self.pid = self.ptyproc.pid
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self.child_fd = self.ptyproc.fd
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self.terminated = False
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self.closed = False
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def _spawnpty(self, args, **kwargs):
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'''Spawn a pty and return an instance of PtyProcess.'''
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return ptyprocess.PtyProcess.spawn(args, **kwargs)
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def close(self, force=True):
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'''This closes the connection with the child application. Note that
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calling close() more than once is valid. This emulates standard Python
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behavior with files. Set force to True if you want to make sure that
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the child is terminated (SIGKILL is sent if the child ignores SIGHUP
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and SIGINT). '''
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self.flush()
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with _wrap_ptyprocess_err():
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# PtyProcessError may be raised if it is not possible to terminate
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# the child.
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self.ptyproc.close(force=force)
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self.isalive() # Update exit status from ptyproc
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self.child_fd = -1
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self.closed = True
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def isatty(self):
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'''This returns True if the file descriptor is open and connected to a
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tty(-like) device, else False.
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On SVR4-style platforms implementing streams, such as SunOS and HP-UX,
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the child pty may not appear as a terminal device. This means
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methods such as setecho(), setwinsize(), getwinsize() may raise an
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IOError. '''
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return os.isatty(self.child_fd)
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def waitnoecho(self, timeout=-1):
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'''This waits until the terminal ECHO flag is set False. This returns
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True if the echo mode is off. This returns False if the ECHO flag was
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not set False before the timeout. This can be used to detect when the
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child is waiting for a password. Usually a child application will turn
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off echo mode when it is waiting for the user to enter a password. For
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example, instead of expecting the "password:" prompt you can wait for
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the child to set ECHO off::
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p = pexpect.spawn('ssh user@example.com')
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p.waitnoecho()
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p.sendline(mypassword)
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If timeout==-1 then this method will use the value in self.timeout.
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If timeout==None then this method to block until ECHO flag is False.
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'''
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if timeout == -1:
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timeout = self.timeout
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if timeout is not None:
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end_time = time.time() + timeout
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while True:
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if not self.getecho():
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return True
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if timeout < 0 and timeout is not None:
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return False
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if timeout is not None:
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timeout = end_time - time.time()
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time.sleep(0.1)
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def getecho(self):
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'''This returns the terminal echo mode. This returns True if echo is
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on or False if echo is off. Child applications that are expecting you
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to enter a password often set ECHO False. See waitnoecho().
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Not supported on platforms where ``isatty()`` returns False. '''
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return self.ptyproc.getecho()
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def setecho(self, state):
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'''This sets the terminal echo mode on or off. Note that anything the
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child sent before the echo will be lost, so you should be sure that
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your input buffer is empty before you call setecho(). For example, the
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following will work as expected::
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p = pexpect.spawn('cat') # Echo is on by default.
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p.sendline('1234') # We expect see this twice from the child...
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p.expect(['1234']) # ... once from the tty echo...
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p.expect(['1234']) # ... and again from cat itself.
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p.setecho(False) # Turn off tty echo
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p.sendline('abcd') # We will set this only once (echoed by cat).
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p.sendline('wxyz') # We will set this only once (echoed by cat)
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p.expect(['abcd'])
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p.expect(['wxyz'])
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The following WILL NOT WORK because the lines sent before the setecho
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will be lost::
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p = pexpect.spawn('cat')
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p.sendline('1234')
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p.setecho(False) # Turn off tty echo
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p.sendline('abcd') # We will set this only once (echoed by cat).
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p.sendline('wxyz') # We will set this only once (echoed by cat)
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p.expect(['1234'])
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p.expect(['1234'])
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p.expect(['abcd'])
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p.expect(['wxyz'])
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Not supported on platforms where ``isatty()`` returns False.
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'''
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return self.ptyproc.setecho(state)
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def read_nonblocking(self, size=1, timeout=-1):
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'''This reads at most size characters from the child application. It
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includes a timeout. If the read does not complete within the timeout
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period then a TIMEOUT exception is raised. If the end of file is read
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then an EOF exception will be raised. If a logfile is specified, a
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copy is written to that log.
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If timeout is None then the read may block indefinitely.
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If timeout is -1 then the self.timeout value is used. If timeout is 0
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then the child is polled and if there is no data immediately ready
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then this will raise a TIMEOUT exception.
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The timeout refers only to the amount of time to read at least one
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character. This is not affected by the 'size' parameter, so if you call
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read_nonblocking(size=100, timeout=30) and only one character is
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available right away then one character will be returned immediately.
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It will not wait for 30 seconds for another 99 characters to come in.
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On the other hand, if there are bytes available to read immediately,
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all those bytes will be read (up to the buffer size). So, if the
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buffer size is 1 megabyte and there is 1 megabyte of data available
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to read, the buffer will be filled, regardless of timeout.
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This is a wrapper around os.read(). It uses select.select() or
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select.poll() to implement the timeout. '''
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if self.closed:
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raise ValueError('I/O operation on closed file.')
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if self.use_poll:
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def select(timeout):
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return poll_ignore_interrupts([self.child_fd], timeout)
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else:
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def select(timeout):
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return select_ignore_interrupts([self.child_fd], [], [], timeout)[0]
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# If there is data available to read right now, read as much as
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# we can. We do this to increase performance if there are a lot
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# 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)
|