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authorThomas Kluyver <takowl@gmail.com>2014-10-10 17:28:39 -0700
committerThomas Kluyver <takowl@gmail.com>2014-11-23 16:42:42 -0800
commit28220d68c1fad0db883883a962293194a6a31503 (patch)
tree9b982cfe16729a19e070b42b0e0e03ade662672e /pexpect/__init__.py
parentd338e2be8f622fa2aab414300f77152072182c35 (diff)
downloadpexpect-git-28220d68c1fad0db883883a962293194a6a31503.tar.gz
Move code out of __init__
Diffstat (limited to 'pexpect/__init__.py')
-rw-r--r--pexpect/__init__.py1655
1 files changed, 6 insertions, 1649 deletions
diff --git a/pexpect/__init__.py b/pexpect/__init__.py
index 4d0d180..9a914eb 100644
--- a/pexpect/__init__.py
+++ b/pexpect/__init__.py
@@ -63,85 +63,19 @@ PEXPECT LICENSE
'''
-try:
- import os
- import sys
- import time
- import select
- import re
- import types
- import pty
- import tty
- import termios
- import errno
- import traceback
- import signal
- import codecs
- import stat
-except ImportError: # pragma: no cover
- err = sys.exc_info()[1]
- raise ImportError(str(err) + '''
+import sys
+import types
-A critical module was not found. Probably this operating system does not
-support it. Pexpect is intended for UNIX-like operating systems.''')
-
-from contextlib import contextmanager
-
-try:
- import ptyprocess
-except ImportError:
- raise # For now. Work out what to do for Windows support here.
-
-@contextmanager
-def _wrap_ptyprocess_err():
- """Turn ptyprocess errors into our own ExceptionPexpect errors"""
- try:
- yield
- except ptyprocess.PtyProcessError as e:
- raise ExceptionPexpect(*e.args)
-
-from .expect import Expecter
+from .exceptions import ExceptionPexpect, EOF, TIMEOUT
+from .utils import split_command_line, which, is_executable_file
+from .pty_spawn import spawn, spawnu, PY3
+from .expect import Expecter, searcher_re, searcher_string
__version__ = '3.3'
__revision__ = ''
__all__ = ['ExceptionPexpect', 'EOF', 'TIMEOUT', 'spawn', 'spawnu', 'run', 'runu',
'which', 'split_command_line', '__version__', '__revision__']
-PY3 = (sys.version_info[0] >= 3)
-
-# Exception classes used by this module.
-class ExceptionPexpect(Exception):
- '''Base class for all exceptions raised by this module.
- '''
-
- def __init__(self, value):
- super(ExceptionPexpect, self).__init__(value)
- self.value = value
-
- def __str__(self):
- return str(self.value)
-
- def get_trace(self):
- '''This returns an abbreviated stack trace with lines that only concern
- the caller. In other words, the stack trace inside the Pexpect module
- is not included. '''
-
- tblist = traceback.extract_tb(sys.exc_info()[2])
- tblist = [item for item in tblist if ('pexpect/__init__' not in item[0])
- and ('pexpect/expect' not in item[0])]
- tblist = traceback.format_list(tblist)
- return ''.join(tblist)
-
-
-class EOF(ExceptionPexpect):
- '''Raised when EOF is read from a child.
- This usually means the child has exited.'''
-
-
-class TIMEOUT(ExceptionPexpect):
- '''Raised when a read time exceeds the timeout. '''
-
-
def run(command, timeout=-1, withexitstatus=False, events=None,
extra_args=None, logfile=None, cwd=None, env=None):
@@ -295,1582 +229,5 @@ def _run(command, timeout, withexitstatus, events, extra_args, logfile, cwd,
else:
return child_result
-class spawn(object):
- '''This is the main class interface for Pexpect. Use this class to start
- and control child applications. '''
- string_type = bytes
- if PY3:
- allowed_string_types = (bytes, str)
- @staticmethod
- def _chr(c):
- return bytes([c])
- linesep = os.linesep.encode('ascii')
- crlf = '\r\n'.encode('ascii')
-
- @staticmethod
- 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'))
- else:
- allowed_string_types = (basestring,) # analysis:ignore
- _chr = staticmethod(chr)
- linesep = os.linesep
- crlf = '\r\n'
- write_to_stdout = sys.stdout.write
-
- ptyprocess_class = ptyprocess.PtyProcess
- encoding = None
-
- def __init__(self, command, args=[], timeout=30, maxread=2000,
- searchwindowsize=None, logfile=None, cwd=None, env=None,
- ignore_sighup=True, echo=True):
-
- '''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.
-
- The searchwindowsize attribute sets the how far back in the incoming
- seach buffer Pexpect will search for pattern matches. Every time
- Pexpect reads some data from the child it will append the data to the
- incoming buffer. The default is to search from the beginning of the
- incoming buffer each time new data is read from the child. But this is
- very inefficient if you are running a command that generates a large
- amount of data where you want to match. The searchwindowsize does not
- affect the size of the incoming data buffer. You will still have
- access to the full buffer after expect() returns.
-
- 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, spawnu should be used to give str to stdout:
- child = pexpect.spawnu('some_command')
- 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
-
- Remember to use spawnu instead of spawn for 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. For now, the default is True, to preserve the behaviour of
- earlier versions of Pexpect, but you should pass this explicitly if you
- want to rely on it.
-
- 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 0 to return to the old behavior. Most Linux machines
- don't like this to be below 0.03. I don't know why.
-
- 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.
- 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.
- '''
-
- self.STDIN_FILENO = pty.STDIN_FILENO
- self.STDOUT_FILENO = pty.STDOUT_FILENO
- self.STDERR_FILENO = pty.STDERR_FILENO
- 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
- self.pid = 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 = self.string_type()
- # Data before searchwindowsize point is preserved, but not searched.
- self.searchwindowsize = searchwindowsize
- # Delay used before sending data to child. Time in seconds.
- # Most Linux machines don't like this to be below 0.03 (30 ms).
- 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
- self.softspace = False
- self.name = '<' + repr(self) + '>'
- self.closed = True
- self.cwd = cwd
- self.env = env
- self.echo = echo
- self.ignore_sighup = ignore_sighup
- _platform = sys.platform.lower()
- # This flags if we are running on irix
- self.__irix_hack = _platform.startswith('irix')
- # Solaris uses internal __fork_pty(). All others use pty.fork().
- self.use_native_pty_fork = not (
- _platform.startswith('solaris') or
- _platform.startswith('sunos'))
- # inherit EOF and INTR definitions from controlling process.
- try:
- from termios import VEOF, VINTR
- try:
- fd = sys.__stdin__.fileno()
- except ValueError:
- # ValueError: I/O operation on closed file
- fd = sys.__stdout__.fileno()
- self._INTR = ord(termios.tcgetattr(fd)[6][VINTR])
- self._EOF = ord(termios.tcgetattr(fd)[6][VEOF])
- except (ImportError, OSError, IOError, ValueError, termios.error):
- # unless the controlling process is also not a terminal,
- # such as cron(1), or when stdin and stdout are both closed.
- # Fall-back to using CEOF and CINTR. There
- try:
- from termios import CEOF, CINTR
- (self._INTR, self._EOF) = (CINTR, CEOF)
- except ImportError:
- # ^C, ^D
- (self._INTR, self._EOF) = (3, 4)
- # Support subclasses that do not use command or args.
- if command is None:
- self.command = None
- self.args = None
- self.name = '<pexpect factory incomplete>'
- else:
- self._spawn(command, args)
-
- @staticmethod
- def _coerce_expect_string(s):
- if not isinstance(s, bytes):
- return s.encode('ascii')
- return s
-
- @staticmethod
- def _coerce_send_string(s):
- if not isinstance(s, bytes):
- return s.encode('utf-8')
- return s
-
- @staticmethod
- def _coerce_read_string(s):
- return s
-
- def __str__(self):
- '''This returns a human-readable string that represents the state of
- the object. '''
-
- s = []
- s.append(repr(self))
- s.append('version: ' + __version__)
- s.append('command: ' + str(self.command))
- s.append('args: %r' % (self.args,))
- s.append('searcher: %r' % (self.searcher,))
- s.append('buffer (last 100 chars): %r' % (
- self.buffer[-100:] if self.buffer else self.buffer,))
- s.append('before (last 100 chars): %r' % (
- self.before[-100:] if self.before else self.before,))
- 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))
- 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=[]):
- '''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)
- 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}
- if self.ignore_sighup:
- kwargs['before_exec'] = [lambda: signal.signal(signal.SIGHUP, signal.SIG_IGN)]
- self.ptyproc = self.ptyprocess_class.spawn(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 fileno(self):
- '''This returns the file descriptor of the pty for the child.
- '''
- return self.child_fd
-
- 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()
- self.ptyproc.close()
- self.isalive() # Update exit status from ptyproc
- self.child_fd = -1
-
- def flush(self):
- '''This does nothing. It is here to support the interface for a
- File-like object. '''
-
- pass
-
- 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)
-
- self.echo = state
-
- 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()
-
- 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 log file was set using
- setlog() then all data will also be written to the log file.
-
- 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 effected 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.
-
- This is a wrapper around os.read(). It uses select.select() to
- implement the timeout. '''
-
- if self.closed:
- raise ValueError('I/O operation on closed file.')
-
- if timeout == -1:
- timeout = self.timeout
-
- # 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 this case, I test isalive() before doing any reading.
- # If isalive() is false, then I pretend that this is the same as EOF.
- if not self.isalive():
- # timeout of 0 means "poll"
- r, w, e = self.__select([self.child_fd], [], [], 0)
- if not r:
- 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.
- # FIXME So does this mean Irix systems are forced to always have
- # FIXME a 2 second delay when calling read_nonblocking? That sucks.
- r, w, e = self.__select([self.child_fd], [], [], 2)
- if not r and not self.isalive():
- self.flag_eof = True
- raise EOF('End Of File (EOF). Slow platform.')
-
- r, w, e = self.__select([self.child_fd], [], [], timeout)
-
- if not r:
- 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.')
-
- if self.child_fd in r:
- 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._coerce_read_string(s)
- self._log(s, 'read')
- return s
-
- raise ExceptionPexpect('Reached an unexpected state.') # pragma: no cover
-
- 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 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. '''
-
- time.sleep(self.delaybeforesend)
-
- s = self._coerce_send_string(s)
- self._log(s, 'send')
-
- return self._send(s)
-
- def _send(self, s):
- return os.write(self.child_fd, s)
-
- def sendline(self, s=''):
- '''Wraps send(), sending string ``s`` to child process, with os.linesep
- automatically appended. Returns number of bytes written. '''
-
- n = self.send(s)
- n = n + self.send(self.linesep)
- return n
-
- 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().
- '''
-
- char = char.lower()
- a = ord(char)
- if a >= 97 and a <= 122:
- a = a - ord('a') + 1
- return self.send(self._chr(a))
- d = {'@': 0, '`': 0,
- '[': 27, '{': 27,
- '\\': 28, '|': 28,
- ']': 29, '}': 29,
- '^': 30, '~': 30,
- '_': 31,
- '?': 127}
- if char not in d:
- return 0
- return self.send(self._chr(d[char]))
-
- 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. '''
-
- self.send(self._chr(self._EOF))
-
- def sendintr(self):
-
- '''This sends a SIGINT to the child. It does not require
- the SIGINT to be the first character on a line. '''
-
- self.send(self._chr(self._INTR))
-
- @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. '''
-
- ptyproc = self.ptyproc
- with _wrap_ptyprocess_err():
- 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 _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
-
- After a match is found the instance attributes 'before', 'after' and
- 'match' will be set. You can see all the data read before the match in
- 'before'. You can see the data that was matched in 'after'. The
- re.MatchObject used in the re match will be in 'match'. If an error
- occurred then 'before' will be set to all the data read so far and
- 'after' and 'match' will be None.
-
- If timeout is -1 then timeout will be set to the self.timeout value.
-
- 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(). If timeout==-1 then
- the self.timeout value is used. If searchwindowsize==-1 then the
- self.searchwindowsize value is used.
-
- 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 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 stop. The default for
- escape_character is ^]. This should not be confused with ASCII 27 --
- the ESC character. ASCII 29 was chosen for historical merit because
- this is the character used by 'telnet' as the escape character. The
- escape_character will not be sent to the child process.
-
- You may pass in optional input and output filter functions. These
- functions should take a string and return a string. 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))
- global p
- p.setwinsize(a[0],a[1])
- # Note this 'p' 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.string_type()
- mode = tty.tcgetattr(self.STDIN_FILENO)
- tty.setraw(self.STDIN_FILENO)
- if 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():
- r, w, e = self.__select([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)
- if self.logfile is not None:
- self.logfile.write(data)
- self.logfile.flush()
- 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 = data.rfind(escape_character)
- if i != -1:
- data = data[:i]
- self.__interact_writen(self.child_fd, data)
- break
- self.__interact_writen(self.child_fd, data)
-
- def __select(self, iwtd, owtd, ewtd, timeout=None):
-
- '''This is a wrapper around select.select() that ignores signals. If
- select.select raises a select.error exception and errno is an EINTR
- error then it is ignored. Mainly this is used to ignore sigwinch
- (terminal resize). '''
-
- # if select() is interrupted by a signal (errno==EINTR) then
- # we loop back and enter the select() again.
- if timeout is not None:
- end_time = time.time() + timeout
- while True:
- try:
- return select.select(iwtd, owtd, ewtd, timeout)
- except select.error:
- err = sys.exc_info()[1]
- if err.args[0] == errno.EINTR:
- # if we loop back we have to subtract the
- # amount of time we already waited.
- if timeout is not None:
- timeout = end_time - time.time()
- if timeout < 0:
- return([], [], [])
- else:
- # something else caused the select.error, so
- # this actually is an exception.
- raise
-
-##############################################################################
-# The following methods are no longer supported or allowed.
-
- def setmaxread(self, maxread): # pragma: no cover
-
- '''This method is no longer supported or allowed. I don't like getters
- and setters without a good reason. '''
-
- raise ExceptionPexpect('This method is no longer supported ' +
- 'or allowed. Just assign a value to the ' +
- 'maxread member variable.')
-
- def setlog(self, fileobject): # pragma: no cover
-
- '''This method is no longer supported or allowed.
- '''
-
- raise ExceptionPexpect('This method is no longer supported ' +
- 'or allowed. Just assign a value to the logfile ' +
- 'member variable.')
-
-##############################################################################
-# End of spawn class
-##############################################################################
-
-class spawnu(spawn):
- """Works like spawn, but accepts and returns unicode strings.
-
- Extra parameters:
-
- :param encoding: The encoding to use for communications (default: 'utf-8')
- :param errors: How to handle encoding/decoding errors; one of 'strict'
- (the default), 'ignore', or 'replace', as described
- for :meth:`~bytes.decode` and :meth:`~str.encode`.
- """
- if PY3:
- string_type = str
- allowed_string_types = (str, )
- _chr = staticmethod(chr)
- linesep = os.linesep
- crlf = '\r\n'
- else:
- string_type = unicode
- allowed_string_types = (unicode, )
- _chr = staticmethod(unichr)
- linesep = os.linesep.decode('ascii')
- crlf = '\r\n'.decode('ascii')
- # This can handle unicode in both Python 2 and 3
- write_to_stdout = sys.stdout.write
- ptyprocess_class = ptyprocess.PtyProcessUnicode
-
- def __init__(self, *args, **kwargs):
- self.encoding = kwargs.pop('encoding', 'utf-8')
- self.errors = kwargs.pop('errors', 'strict')
- self._decoder = codecs.getincrementaldecoder(self.encoding)(errors=self.errors)
- super(spawnu, self).__init__(*args, **kwargs)
-
- @staticmethod
- def _coerce_expect_string(s):
- return s
-
- @staticmethod
- def _coerce_send_string(s):
- return s
-
- def _coerce_read_string(self, s):
- return self._decoder.decode(s, final=False)
-
- def _send(self, s):
- return os.write(self.child_fd, s.encode(self.encoding, self.errors))
-
-
-class searcher_string(object):
-
- '''This is a plain string search helper for the spawn.expect_any() method.
- This helper class is for speed. For more powerful regex patterns
- see the helper class, searcher_re.
-
- Attributes:
-
- eof_index - index of EOF, or -1
- timeout_index - index of TIMEOUT, or -1
-
- After a successful match by the search() method the following attributes
- are available:
-
- start - index into the buffer, first byte of match
- end - index into the buffer, first byte after match
- match - the matching string itself
-
- '''
-
- def __init__(self, strings):
-
- '''This creates an instance of searcher_string. This argument 'strings'
- may be a list; a sequence of strings; or the EOF or TIMEOUT types. '''
-
- self.eof_index = -1
- self.timeout_index = -1
- self._strings = []
- for n, s in enumerate(strings):
- if s is EOF:
- self.eof_index = n
- continue
- if s is TIMEOUT:
- self.timeout_index = n
- continue
- self._strings.append((n, s))
-
- def __str__(self):
-
- '''This returns a human-readable string that represents the state of
- the object.'''
-
- ss = [(ns[0], ' %d: "%s"' % ns) for ns in self._strings]
- ss.append((-1, 'searcher_string:'))
- if self.eof_index >= 0:
- ss.append((self.eof_index, ' %d: EOF' % self.eof_index))
- if self.timeout_index >= 0:
- ss.append((self.timeout_index,
- ' %d: TIMEOUT' % self.timeout_index))
- ss.sort()
- ss = list(zip(*ss))[1]
- return '\n'.join(ss)
-
- def search(self, buffer, freshlen, searchwindowsize=None):
-
- '''This searches 'buffer' for the first occurence of one of the search
- strings. 'freshlen' must indicate the number of bytes at the end of
- 'buffer' which have not been searched before. It helps to avoid
- searching the same, possibly big, buffer over and over again.
-
- See class spawn for the 'searchwindowsize' argument.
-
- If there is a match this returns the index of that string, and sets
- 'start', 'end' and 'match'. Otherwise, this returns -1. '''
-
- first_match = None
-
- # 'freshlen' helps a lot here. Further optimizations could
- # possibly include:
- #
- # using something like the Boyer-Moore Fast String Searching
- # Algorithm; pre-compiling the search through a list of
- # strings into something that can scan the input once to
- # search for all N strings; realize that if we search for
- # ['bar', 'baz'] and the input is '...foo' we need not bother
- # rescanning until we've read three more bytes.
- #
- # Sadly, I don't know enough about this interesting topic. /grahn
-
- for index, s in self._strings:
- if searchwindowsize is None:
- # the match, if any, can only be in the fresh data,
- # or at the very end of the old data
- offset = -(freshlen + len(s))
- else:
- # better obey searchwindowsize
- offset = -searchwindowsize
- n = buffer.find(s, offset)
- if n >= 0 and (first_match is None or n < first_match):
- first_match = n
- best_index, best_match = index, s
- if first_match is None:
- return -1
- self.match = best_match
- self.start = first_match
- self.end = self.start + len(self.match)
- return best_index
-
-
-class searcher_re(object):
-
- '''This is regular expression string search helper for the
- spawn.expect_any() method. This helper class is for powerful
- pattern matching. For speed, see the helper class, searcher_string.
-
- Attributes:
-
- eof_index - index of EOF, or -1
- timeout_index - index of TIMEOUT, or -1
-
- After a successful match by the search() method the following attributes
- are available:
-
- start - index into the buffer, first byte of match
- end - index into the buffer, first byte after match
- match - the re.match object returned by a succesful re.search
-
- '''
-
- def __init__(self, patterns):
-
- '''This creates an instance that searches for 'patterns' Where
- 'patterns' may be a list or other sequence of compiled regular
- expressions, or the EOF or TIMEOUT types.'''
-
- self.eof_index = -1
- self.timeout_index = -1
- self._searches = []
- for n, s in zip(list(range(len(patterns))), patterns):
- if s is EOF:
- self.eof_index = n
- continue
- if s is TIMEOUT:
- self.timeout_index = n
- continue
- self._searches.append((n, s))
-
- def __str__(self):
-
- '''This returns a human-readable string that represents the state of
- the object.'''
-
- #ss = [(n, ' %d: re.compile("%s")' %
- # (n, repr(s.pattern))) for n, s in self._searches]
- ss = list()
- for n, s in self._searches:
- try:
- ss.append((n, ' %d: re.compile("%s")' % (n, s.pattern)))
- except UnicodeEncodeError:
- # for test cases that display __str__ of searches, dont throw
- # another exception just because stdout is ascii-only, using
- # repr()
- ss.append((n, ' %d: re.compile(%r)' % (n, s.pattern)))
- ss.append((-1, 'searcher_re:'))
- if self.eof_index >= 0:
- ss.append((self.eof_index, ' %d: EOF' % self.eof_index))
- if self.timeout_index >= 0:
- ss.append((self.timeout_index, ' %d: TIMEOUT' %
- self.timeout_index))
- ss.sort()
- ss = list(zip(*ss))[1]
- return '\n'.join(ss)
-
- def search(self, buffer, freshlen, searchwindowsize=None):
-
- '''This searches 'buffer' for the first occurence of one of the regular
- expressions. 'freshlen' must indicate the number of bytes at the end of
- 'buffer' which have not been searched before.
-
- See class spawn for the 'searchwindowsize' argument.
-
- If there is a match this returns the index of that string, and sets
- 'start', 'end' and 'match'. Otherwise, returns -1.'''
-
- first_match = None
- # 'freshlen' doesn't help here -- we cannot predict the
- # length of a match, and the re module provides no help.
- if searchwindowsize is None:
- searchstart = 0
- else:
- searchstart = max(0, len(buffer) - searchwindowsize)
- for index, s in self._searches:
- match = s.search(buffer, searchstart)
- if match is None:
- continue
- n = match.start()
- if first_match is None or n < first_match:
- first_match = n
- the_match = match
- best_index = index
- if first_match is None:
- return -1
- self.start = first_match
- self.match = the_match
- self.end = self.match.end()
- return best_index
-
-
-def is_executable_file(path):
- """Checks that path is an executable regular file (or a symlink to a file).
-
- This is roughly ``os.path isfile(path) and os.access(path, os.X_OK)``, but
- on some platforms :func:`os.access` gives us the wrong answer, so this
- checks permission bits directly.
- """
- # follow symlinks,
- fpath = os.path.realpath(path)
-
- # return False for non-files (directories, fifo, etc.)
- if not os.path.isfile(fpath):
- return False
-
- # On Solaris, etc., "If the process has appropriate privileges, an
- # implementation may indicate success for X_OK even if none of the
- # execute file permission bits are set."
- #
- # For this reason, it is necessary to explicitly check st_mode
-
- # get file mode using os.stat, and check if `other',
- # that is anybody, may read and execute.
- mode = os.stat(fpath).st_mode
- if mode & stat.S_IROTH and mode & stat.S_IXOTH:
- return True
-
- # get current user's group ids, and check if `group',
- # when matching ours, may read and execute.
- user_gids = os.getgroups() + [os.getgid()]
- if (os.stat(fpath).st_gid in user_gids and
- mode & stat.S_IRGRP and mode & stat.S_IXGRP):
- return True
-
- # finally, if file owner matches our effective userid,
- # check if `user', may read and execute.
- user_gids = os.getgroups() + [os.getgid()]
- if (os.stat(fpath).st_uid == os.geteuid() and
- mode & stat.S_IRUSR and mode & stat.S_IXUSR):
- return True
-
- return False
-
-def which(filename):
- '''This takes a given filename; tries to find it in the environment path;
- then checks if it is executable. This returns the full path to the filename
- if found and executable. Otherwise this returns None.'''
-
- # Special case where filename contains an explicit path.
- if os.path.dirname(filename) != '' and is_executable_file(filename):
- return filename
- if 'PATH' not in os.environ or os.environ['PATH'] == '':
- p = os.defpath
- else:
- p = os.environ['PATH']
- pathlist = p.split(os.pathsep)
- for path in pathlist:
- ff = os.path.join(path, filename)
- if is_executable_file(ff):
- return ff
- return None
-
-
-def split_command_line(command_line):
-
- '''This splits a command line into a list of arguments. It splits arguments
- on spaces, but handles embedded quotes, doublequotes, and escaped
- characters. It's impossible to do this with a regular expression, so I
- wrote a little state machine to parse the command line. '''
-
- arg_list = []
- arg = ''
-
- # Constants to name the states we can be in.
- state_basic = 0
- state_esc = 1
- state_singlequote = 2
- state_doublequote = 3
- # The state when consuming whitespace between commands.
- state_whitespace = 4
- state = state_basic
-
- for c in command_line:
- if state == state_basic or state == state_whitespace:
- if c == '\\':
- # Escape the next character
- state = state_esc
- elif c == r"'":
- # Handle single quote
- state = state_singlequote
- elif c == r'"':
- # Handle double quote
- state = state_doublequote
- elif c.isspace():
- # Add arg to arg_list if we aren't in the middle of whitespace.
- if state == state_whitespace:
- # Do nothing.
- None
- else:
- arg_list.append(arg)
- arg = ''
- state = state_whitespace
- else:
- arg = arg + c
- state = state_basic
- elif state == state_esc:
- arg = arg + c
- state = state_basic
- elif state == state_singlequote:
- if c == r"'":
- state = state_basic
- else:
- arg = arg + c
- elif state == state_doublequote:
- if c == r'"':
- state = state_basic
- else:
- arg = arg + c
-
- if arg != '':
- arg_list.append(arg)
- return arg_list
# vim: set shiftround expandtab tabstop=4 shiftwidth=4 ft=python autoindent :