--- /dev/null
+#!/usr/bin/env python
+
+"""This module implements a Finite State Machine (FSM). In addition to state
+this FSM also maintains a user defined "memory". So this FSM can be used as a
+Push-down Automata (PDA) since a PDA is a FSM + memory.
+
+The following describes how the FSM works, but you will probably also need to
+see the example function to understand how the FSM is used in practice.
+
+You define an FSM by building tables of transitions. For a given input symbol
+the process() method uses these tables to decide what action to call and what
+the next state will be. The FSM has a table of transitions that associate:
+
+ (input_symbol, current_state) --> (action, next_state)
+
+Where "action" is a function you define. The symbols and states can be any
+objects. You use the add_transition() and add_transition_list() methods to add
+to the transition table. The FSM also has a table of transitions that
+associate:
+
+ (current_state) --> (action, next_state)
+
+You use the add_transition_any() method to add to this transition table. The
+FSM also has one default transition that is not associated with any specific
+input_symbol or state. You use the set_default_transition() method to set the
+default transition.
+
+When an action function is called it is passed a reference to the FSM. The
+action function may then access attributes of the FSM such as input_symbol,
+current_state, or "memory". The "memory" attribute can be any object that you
+want to pass along to the action functions. It is not used by the FSM itself.
+For parsing you would typically pass a list to be used as a stack.
+
+The processing sequence is as follows. The process() method is given an
+input_symbol to process. The FSM will search the table of transitions that
+associate:
+
+ (input_symbol, current_state) --> (action, next_state)
+
+If the pair (input_symbol, current_state) is found then process() will call the
+associated action function and then set the current state to the next_state.
+
+If the FSM cannot find a match for (input_symbol, current_state) it will then
+search the table of transitions that associate:
+
+ (current_state) --> (action, next_state)
+
+If the current_state is found then the process() method will call the
+associated action function and then set the current state to the next_state.
+Notice that this table lacks an input_symbol. It lets you define transitions
+for a current_state and ANY input_symbol. Hence, it is called the "any" table.
+Remember, it is always checked after first searching the table for a specific
+(input_symbol, current_state).
+
+For the case where the FSM did not match either of the previous two cases the
+FSM will try to use the default transition. If the default transition is
+defined then the process() method will call the associated action function and
+then set the current state to the next_state. This lets you define a default
+transition as a catch-all case. You can think of it as an exception handler.
+There can be only one default transition.
+
+Finally, if none of the previous cases are defined for an input_symbol and
+current_state then the FSM will raise an exception. This may be desirable, but
+you can always prevent this just by defining a default transition.
+
+Noah Spurrier 20020822
+"""
+
+class ExceptionFSM(Exception):
+
+ """This is the FSM Exception class."""
+
+ def __init__(self, value):
+ self.value = value
+
+ def __str__(self):
+ return `self.value`
+
+class FSM:
+
+ """This is a Finite State Machine (FSM).
+ """
+
+ def __init__(self, initial_state, memory=None):
+
+ """This creates the FSM. You set the initial state here. The "memory"
+ attribute is any object that you want to pass along to the action
+ functions. It is not used by the FSM. For parsing you would typically
+ pass a list to be used as a stack. """
+
+ # Map (input_symbol, current_state) --> (action, next_state).
+ self.state_transitions = {}
+ # Map (current_state) --> (action, next_state).
+ self.state_transitions_any = {}
+ self.default_transition = None
+
+ self.input_symbol = None
+ self.initial_state = initial_state
+ self.current_state = self.initial_state
+ self.next_state = None
+ self.action = None
+ self.memory = memory
+
+ def reset (self):
+
+ """This sets the current_state to the initial_state and sets
+ input_symbol to None. The initial state was set by the constructor
+ __init__(). """
+
+ self.current_state = self.initial_state
+ self.input_symbol = None
+
+ def add_transition (self, input_symbol, state, action=None, next_state=None):
+
+ """This adds a transition that associates:
+
+ (input_symbol, current_state) --> (action, next_state)
+
+ The action may be set to None in which case the process() method will
+ ignore the action and only set the next_state. The next_state may be
+ set to None in which case the current state will be unchanged.
+
+ You can also set transitions for a list of symbols by using
+ add_transition_list(). """
+
+ if next_state is None:
+ next_state = state
+ self.state_transitions[(input_symbol, state)] = (action, next_state)
+
+ def add_transition_list (self, list_input_symbols, state, action=None, next_state=None):
+
+ """This adds the same transition for a list of input symbols.
+ You can pass a list or a string. Note that it is handy to use
+ string.digits, string.whitespace, string.letters, etc. to add
+ transitions that match character classes.
+
+ The action may be set to None in which case the process() method will
+ ignore the action and only set the next_state. The next_state may be
+ set to None in which case the current state will be unchanged. """
+
+ if next_state is None:
+ next_state = state
+ for input_symbol in list_input_symbols:
+ self.add_transition (input_symbol, state, action, next_state)
+
+ def add_transition_any (self, state, action=None, next_state=None):
+
+ """This adds a transition that associates:
+
+ (current_state) --> (action, next_state)
+
+ That is, any input symbol will match the current state.
+ The process() method checks the "any" state associations after it first
+ checks for an exact match of (input_symbol, current_state).
+
+ The action may be set to None in which case the process() method will
+ ignore the action and only set the next_state. The next_state may be
+ set to None in which case the current state will be unchanged. """
+
+ if next_state is None:
+ next_state = state
+ self.state_transitions_any [state] = (action, next_state)
+
+ def set_default_transition (self, action, next_state):
+
+ """This sets the default transition. This defines an action and
+ next_state if the FSM cannot find the input symbol and the current
+ state in the transition list and if the FSM cannot find the
+ current_state in the transition_any list. This is useful as a final
+ fall-through state for catching errors and undefined states.
+
+ The default transition can be removed by setting the attribute
+ default_transition to None. """
+
+ self.default_transition = (action, next_state)
+
+ def get_transition (self, input_symbol, state):
+
+ """This returns (action, next state) given an input_symbol and state.
+ This does not modify the FSM state, so calling this method has no side
+ effects. Normally you do not call this method directly. It is called by
+ process().
+
+ The sequence of steps to check for a defined transition goes from the
+ most specific to the least specific.
+
+ 1. Check state_transitions[] that match exactly the tuple,
+ (input_symbol, state)
+
+ 2. Check state_transitions_any[] that match (state)
+ In other words, match a specific state and ANY input_symbol.
+
+ 3. Check if the default_transition is defined.
+ This catches any input_symbol and any state.
+ This is a handler for errors, undefined states, or defaults.
+
+ 4. No transition was defined. If we get here then raise an exception.
+ """
+
+ if self.state_transitions.has_key((input_symbol, state)):
+ return self.state_transitions[(input_symbol, state)]
+ elif self.state_transitions_any.has_key (state):
+ return self.state_transitions_any[state]
+ elif self.default_transition is not None:
+ return self.default_transition
+ else:
+ raise ExceptionFSM ('Transition is undefined: (%s, %s).' %
+ (str(input_symbol), str(state)) )
+
+ def process (self, input_symbol):
+
+ """This is the main method that you call to process input. This may
+ cause the FSM to change state and call an action. This method calls
+ get_transition() to find the action and next_state associated with the
+ input_symbol and current_state. If the action is None then the action
+ is not called and only the current state is changed. This method
+ processes one complete input symbol. You can process a list of symbols
+ (or a string) by calling process_list(). """
+
+ self.input_symbol = input_symbol
+ (self.action, self.next_state) = self.get_transition (self.input_symbol, self.current_state)
+ if self.action is not None:
+ self.action (self)
+ self.current_state = self.next_state
+ self.next_state = None
+
+ def process_list (self, input_symbols):
+
+ """This takes a list and sends each element to process(). The list may
+ be a string or any iterable object. """
+
+ for s in input_symbols:
+ self.process (s)
+
+##############################################################################
+# The following is an example that demonstrates the use of the FSM class to
+# process an RPN expression. Run this module from the command line. You will
+# get a prompt > for input. Enter an RPN Expression. Numbers may be integers.
+# Operators are * / + - Use the = sign to evaluate and print the expression.
+# For example:
+#
+# 167 3 2 2 * * * 1 - =
+#
+# will print:
+#
+# 2003
+##############################################################################
+
+import sys, os, traceback, optparse, time, string
+
+#
+# These define the actions.
+# Note that "memory" is a list being used as a stack.
+#
+
+def BeginBuildNumber (fsm):
+ fsm.memory.append (fsm.input_symbol)
+
+def BuildNumber (fsm):
+ s = fsm.memory.pop ()
+ s = s + fsm.input_symbol
+ fsm.memory.append (s)
+
+def EndBuildNumber (fsm):
+ s = fsm.memory.pop ()
+ fsm.memory.append (int(s))
+
+def DoOperator (fsm):
+ ar = fsm.memory.pop()
+ al = fsm.memory.pop()
+ if fsm.input_symbol == '+':
+ fsm.memory.append (al + ar)
+ elif fsm.input_symbol == '-':
+ fsm.memory.append (al - ar)
+ elif fsm.input_symbol == '*':
+ fsm.memory.append (al * ar)
+ elif fsm.input_symbol == '/':
+ fsm.memory.append (al / ar)
+
+def DoEqual (fsm):
+ print str(fsm.memory.pop())
+
+def Error (fsm):
+ print 'That does not compute.'
+ print str(fsm.input_symbol)
+
+def main():
+
+ """This is where the example starts and the FSM state transitions are
+ defined. Note that states are strings (such as 'INIT'). This is not
+ necessary, but it makes the example easier to read. """
+
+ f = FSM ('INIT', []) # "memory" will be used as a stack.
+ f.set_default_transition (Error, 'INIT')
+ f.add_transition_any ('INIT', None, 'INIT')
+ f.add_transition ('=', 'INIT', DoEqual, 'INIT')
+ f.add_transition_list (string.digits, 'INIT', BeginBuildNumber, 'BUILDING_NUMBER')
+ f.add_transition_list (string.digits, 'BUILDING_NUMBER', BuildNumber, 'BUILDING_NUMBER')
+ f.add_transition_list (string.whitespace, 'BUILDING_NUMBER', EndBuildNumber, 'INIT')
+ f.add_transition_list ('+-*/', 'INIT', DoOperator, 'INIT')
+
+ print
+ print 'Enter an RPN Expression.'
+ print 'Numbers may be integers. Operators are * / + -'
+ print 'Use the = sign to evaluate and print the expression.'
+ print 'For example: '
+ print ' 167 3 2 2 * * * 1 - ='
+ inputstr = raw_input ('> ')
+ f.process_list(inputstr)
+
+if __name__ == '__main__':
+ try:
+ start_time = time.time()
+ parser = optparse.OptionParser(formatter=optparse.TitledHelpFormatter(), usage=globals()['__doc__'], version='$Id: FSM.py 490 2007-12-07 15:46:24Z noah $')
+ parser.add_option ('-v', '--verbose', action='store_true', default=False, help='verbose output')
+ (options, args) = parser.parse_args()
+ if options.verbose: print time.asctime()
+ main()
+ if options.verbose: print time.asctime()
+ if options.verbose: print 'TOTAL TIME IN MINUTES:',
+ if options.verbose: print (time.time() - start_time) / 60.0
+ sys.exit(0)
+ except KeyboardInterrupt, e: # Ctrl-C
+ raise e
+ except SystemExit, e: # sys.exit()
+ raise e
+ except Exception, e:
+ print 'ERROR, UNEXPECTED EXCEPTION'
+ print str(e)
+ traceback.print_exc()
+ os._exit(1)
--- /dev/null
+"""Pexpect is a Python module for spawning child applications and controlling
+them automatically. Pexpect can be used for automating interactive applications
+such as ssh, ftp, passwd, telnet, etc. It can be used to a automate setup
+scripts for duplicating software package installations on different servers. It
+can be used for automated software testing. Pexpect is in the spirit of Don
+Libes' Expect, but Pexpect is pure Python. Other Expect-like modules for Python
+require TCL and Expect or require C extensions to be compiled. Pexpect does not
+use C, Expect, or TCL extensions. It should work on any platform that supports
+the standard Python pty module. The Pexpect interface focuses on ease of use so
+that simple tasks are easy.
+
+There are two main interfaces to Pexpect -- the function, run() and the class,
+spawn. You can call the run() function to execute a command and return the
+output. This is a handy replacement for os.system().
+
+For example::
+
+ pexpect.run('ls -la')
+
+The more powerful interface is the spawn class. You can use this to spawn an
+external child command and then interact with the child by sending lines and
+expecting responses.
+
+For example::
+
+ child = pexpect.spawn('scp foo myname@host.example.com:.')
+ child.expect ('Password:')
+ child.sendline (mypassword)
+
+This works even for commands that ask for passwords or other input outside of
+the normal stdio streams.
+
+Credits: Noah Spurrier, Richard Holden, Marco Molteni, Kimberley Burchett,
+Robert Stone, Hartmut Goebel, Chad Schroeder, Erick Tryzelaar, Dave Kirby, Ids
+vander Molen, George Todd, Noel Taylor, Nicolas D. Cesar, Alexander Gattin,
+Geoffrey Marshall, Francisco Lourenco, Glen Mabey, Karthik Gurusamy, Fernando
+Perez, Corey Minyard, Jon Cohen, Guillaume Chazarain, Andrew Ryan, Nick
+Craig-Wood, Andrew Stone, Jorgen Grahn (Let me know if I forgot anyone.)
+
+Free, open source, and all that good stuff.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
+Pexpect Copyright (c) 2008 Noah Spurrier
+http://pexpect.sourceforge.net/
+
+$Id: pexpect.py 507 2007-12-27 02:40:52Z noah $
+"""
+
+try:
+ import os, sys, time
+ import select
+ import string
+ import re
+ import struct
+ import resource
+ import types
+ import pty
+ import tty
+ import termios
+ import fcntl
+ import errno
+ import traceback
+ import signal
+except ImportError, e:
+ raise ImportError (str(e) + """
+
+A critical module was not found. Probably this operating system does not
+support it. Pexpect is intended for UNIX-like operating systems.""")
+
+__version__ = '2.3'
+__revision__ = '$Revision: 399 $'
+__all__ = ['ExceptionPexpect', 'EOF', 'TIMEOUT', 'spawn', 'run', 'which',
+ 'split_command_line', '__version__', '__revision__']
+
+# Exception classes used by this module.
+class ExceptionPexpect(Exception):
+
+ """Base class for all exceptions raised by this module.
+ """
+
+ def __init__(self, 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 = filter(self.__filter_not_pexpect, tblist)
+ tblist = [item for item in tblist if self.__filter_not_pexpect(item)]
+ tblist = traceback.format_list(tblist)
+ return ''.join(tblist)
+
+ def __filter_not_pexpect(self, trace_list_item):
+
+ """This returns True if list item 0 the string 'pexpect.py' in it. """
+
+ if trace_list_item[0].find('pexpect.py') == -1:
+ return True
+ else:
+ return False
+
+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. """
+
+##class TIMEOUT_PATTERN(TIMEOUT):
+## """Raised when the pattern match time exceeds the timeout.
+## This is different than a read TIMEOUT because the child process may
+## give output, thus never give a TIMEOUT, but the output
+## may never match a pattern.
+## """
+##class MAXBUFFER(ExceptionPexpect):
+## """Raised when a scan buffer fills before matching an expected pattern."""
+
+def run (command, timeout=-1, withexitstatus=False, events=None, extra_args=None, logfile=None, cwd=None, env=None):
+
+ """
+ This function runs the given command; waits for it to finish; then
+ returns all output as a string. STDERR is included in output. If the full
+ path to the command is not given then the path is searched.
+
+ Note that lines are terminated by CR/LF (\\r\\n) combination even on
+ UNIX-like systems because this is the standard for pseudo ttys. If you set
+ 'withexitstatus' to true, then run will return a tuple of (command_output,
+ exitstatus). If 'withexitstatus' is false then this returns just
+ command_output.
+
+ The run() function can often be used instead of creating a spawn instance.
+ For example, the following code uses spawn::
+
+ from pexpect import *
+ child = spawn('scp foo myname@host.example.com:.')
+ child.expect ('(?i)password')
+ child.sendline (mypassword)
+
+ The previous code can be replace with the following::
+
+ from pexpect import *
+ run ('scp foo myname@host.example.com:.', events={'(?i)password': mypassword})
+
+ Examples
+ ========
+
+ Start the apache daemon on the local machine::
+
+ from pexpect import *
+ run ("/usr/local/apache/bin/apachectl start")
+
+ Check in a file using SVN::
+
+ from pexpect import *
+ run ("svn ci -m 'automatic commit' my_file.py")
+
+ Run a command and capture exit status::
+
+ from pexpect import *
+ (command_output, exitstatus) = run ('ls -l /bin', withexitstatus=1)
+
+ Tricky Examples
+ ===============
+
+ The following will run SSH and execute 'ls -l' on the remote machine. The
+ password 'secret' will be sent if the '(?i)password' pattern is ever seen::
+
+ run ("ssh username@machine.example.com 'ls -l'", events={'(?i)password':'secret\\n'})
+
+ This will start mencoder to rip a video from DVD. This will also display
+ progress ticks every 5 seconds as it runs. For example::
+
+ from pexpect import *
+ def print_ticks(d):
+ print d['event_count'],
+ run ("mencoder dvd://1 -o video.avi -oac copy -ovc copy", events={TIMEOUT:print_ticks}, timeout=5)
+
+ The 'events' argument should be a dictionary of patterns and responses.
+ Whenever one of the patterns is seen in the command out run() will send the
+ associated response string. Note that you should put newlines in your
+ string if Enter is necessary. The responses may also contain callback
+ functions. Any callback is function that takes a dictionary as an argument.
+ The dictionary contains all the locals from the run() function, so you can
+ access the child spawn object or any other variable defined in run()
+ (event_count, child, and extra_args are the most useful). A callback may
+ return True to stop the current run process otherwise run() continues until
+ the next event. A callback may also return a string which will be sent to
+ the child. 'extra_args' is not used by directly run(). It provides a way to
+ pass data to a callback function through run() through the locals
+ dictionary passed to a callback. """
+
+ if timeout == -1:
+ child = spawn(command, maxread=2000, logfile=logfile, cwd=cwd, env=env)
+ else:
+ child = spawn(command, timeout=timeout, maxread=2000, logfile=logfile, cwd=cwd, env=env)
+ if events is not None:
+ patterns = events.keys()
+ responses = events.values()
+ else:
+ patterns=None # We assume that EOF or TIMEOUT will save us.
+ responses=None
+ child_result_list = []
+ event_count = 0
+ while 1:
+ try:
+ index = child.expect (patterns)
+ if type(child.after) in types.StringTypes:
+ child_result_list.append(child.before + child.after)
+ else: # child.after may have been a TIMEOUT or EOF, so don't cat those.
+ child_result_list.append(child.before)
+ if type(responses[index]) in types.StringTypes:
+ child.send(responses[index])
+ elif type(responses[index]) is types.FunctionType:
+ callback_result = responses[index](locals())
+ sys.stdout.flush()
+ if type(callback_result) in types.StringTypes:
+ child.send(callback_result)
+ elif callback_result:
+ break
+ else:
+ raise TypeError ('The callback must be a string or function type.')
+ event_count = event_count + 1
+ except TIMEOUT, e:
+ child_result_list.append(child.before)
+ break
+ except EOF, e:
+ child_result_list.append(child.before)
+ break
+ child_result = ''.join(child_result_list)
+ if withexitstatus:
+ child.close()
+ return (child_result, child.exitstatus)
+ else:
+ return child_result
+
+class spawn (object):
+
+ """This is the main class interface for Pexpect. Use this class to start
+ and control child applications. """
+
+ def __init__(self, command, args=[], timeout=30, maxread=2000, searchwindowsize=None, logfile=None, cwd=None, env=None):
+
+ """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 > log_list.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 > log_list.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 incomming
+ seach buffer Pexpect will search for pattern matches. Every time
+ Pexpect reads some data from the child it will append the data to the
+ incomming buffer. The default is to search from the beginning of the
+ imcomming 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
+ effect the size of the incomming 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 = file('mylog.txt','w')
+ child.logfile = fout
+
+ Example log to stdout::
+
+ child = pexpect.spawn('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
+
+ To separately log output sent to the child use logfile_send::
+
+ self.logfile_send = fout
+
+ 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. """
+
+ 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
+ self.status = None # status returned by os.waitpid
+ self.flag_eof = False
+ self.pid = None
+ self.child_fd = -1 # initially closed
+ self.timeout = timeout
+ self.delimiter = EOF
+ self.logfile = logfile
+ self.logfile_read = None # input from child (read_nonblocking)
+ self.logfile_send = None # output to send (send, sendline)
+ self.maxread = maxread # max bytes to read at one time into buffer
+ self.buffer = '' # This is the read buffer. See maxread.
+ self.searchwindowsize = searchwindowsize # Anything before searchwindowsize point is preserved, but not searched.
+ # Most Linux machines don't like delaybeforesend to be below 0.03 (30 ms).
+ self.delaybeforesend = 0.05 # Sets sleep time used just before sending data to child. Time in seconds.
+ self.delayafterclose = 0.1 # Sets delay in close() method to allow kernel time to update process status. Time in seconds.
+ self.delayafterterminate = 0.1 # Sets delay in terminate() method to allow kernel time to update process status. Time in seconds.
+ self.softspace = False # File-like object.
+ self.name = '<' + repr(self) + '>' # File-like object.
+ self.encoding = None # File-like object.
+ self.closed = True # File-like object.
+ self.cwd = cwd
+ self.env = env
+ self.__irix_hack = (sys.platform.lower().find('irix')>=0) # This flags if we are running on irix
+ # Solaris uses internal __fork_pty(). All others use pty.fork().
+ if (sys.platform.lower().find('solaris')>=0) or (sys.platform.lower().find('sunos5')>=0):
+ self.use_native_pty_fork = False
+ else:
+ self.use_native_pty_fork = True
+
+
+ # allow dummy instances for subclasses that may 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)
+
+ def __del__(self):
+
+ """This makes sure that no system resources are left open. Python only
+ garbage collects Python objects. OS file descriptors are not Python
+ objects, so they must be handled explicitly. If the child file
+ descriptor was opened outside of this class (passed to the constructor)
+ then this does not close it. """
+
+ if not self.closed:
+ # It is possible for __del__ methods to execute during the
+ # teardown of the Python VM itself. Thus self.close() may
+ # trigger an exception because os.close may be None.
+ # -- Fernando Perez
+ try:
+ self.close()
+ except AttributeError:
+ pass
+
+ 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__ + ' (' + __revision__ + ')')
+ s.append('command: ' + str(self.command))
+ s.append('args: ' + str(self.args))
+ s.append('searcher: ' + str(self.searcher))
+ s.append('buffer (last 100 chars): ' + str(self.buffer)[-100:])
+ s.append('before (last 100 chars): ' + str(self.before)[-100:])
+ s.append('after: ' + str(self.after))
+ s.append('match: ' + str(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 haved 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 type(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 type (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:
+ self.args = args[:] # work with a copy
+ 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 should be None.'
+ assert self.command is not None, 'The command member should not be None.'
+
+ if self.use_native_pty_fork:
+ try:
+ self.pid, self.child_fd = pty.fork()
+ except OSError, e:
+ raise ExceptionPexpect('Error! pty.fork() failed: ' + str(e))
+ else: # Use internal __fork_pty
+ self.pid, self.child_fd = self.__fork_pty()
+
+ if self.pid == 0: # Child
+ try:
+ self.child_fd = sys.stdout.fileno() # used by setwinsize()
+ self.setwinsize(24, 80)
+ except:
+ # Some platforms do not like setwinsize (Cygwin).
+ # This will cause problem when running applications that
+ # are very picky about window size.
+ # This is a serious limitation, but not a show stopper.
+ pass
+ # Do not allow child to inherit open file descriptors from parent.
+ max_fd = resource.getrlimit(resource.RLIMIT_NOFILE)[0]
+ for i in range (3, max_fd):
+ try:
+ os.close (i)
+ except OSError:
+ pass
+
+ # I don't know why this works, but ignoring SIGHUP fixes a
+ # problem when trying to start a Java daemon with sudo
+ # (specifically, Tomcat).
+ signal.signal(signal.SIGHUP, signal.SIG_IGN)
+
+ if self.cwd is not None:
+ os.chdir(self.cwd)
+ if self.env is None:
+ os.execv(self.command, self.args)
+ else:
+ os.execvpe(self.command, self.args, self.env)
+
+ # Parent
+ self.terminated = False
+ self.closed = False
+
+ def __fork_pty(self):
+
+ """This implements a substitute for the forkpty system call. This
+ should be more portable than the pty.fork() function. Specifically,
+ this should work on Solaris.
+
+ Modified 10.06.05 by Geoff Marshall: Implemented __fork_pty() method to
+ resolve the issue with Python's pty.fork() not supporting Solaris,
+ particularly ssh. Based on patch to posixmodule.c authored by Noah
+ Spurrier::
+
+ http://mail.python.org/pipermail/python-dev/2003-May/035281.html
+
+ """
+
+ parent_fd, child_fd = os.openpty()
+ if parent_fd < 0 or child_fd < 0:
+ raise ExceptionPexpect, "Error! Could not open pty with os.openpty()."
+
+ pid = os.fork()
+ if pid < 0:
+ raise ExceptionPexpect, "Error! Failed os.fork()."
+ elif pid == 0:
+ # Child.
+ os.close(parent_fd)
+ self.__pty_make_controlling_tty(child_fd)
+
+ os.dup2(child_fd, 0)
+ os.dup2(child_fd, 1)
+ os.dup2(child_fd, 2)
+
+ if child_fd > 2:
+ os.close(child_fd)
+ else:
+ # Parent.
+ os.close(child_fd)
+
+ return pid, parent_fd
+
+ def __pty_make_controlling_tty(self, tty_fd):
+
+ """This makes the pseudo-terminal the controlling tty. This should be
+ more portable than the pty.fork() function. Specifically, this should
+ work on Solaris. """
+
+ child_name = os.ttyname(tty_fd)
+
+ # Disconnect from controlling tty if still connected.
+ fd = os.open("/dev/tty", os.O_RDWR | os.O_NOCTTY);
+ if fd >= 0:
+ os.close(fd)
+
+ os.setsid()
+
+ # Verify we are disconnected from controlling tty
+ try:
+ fd = os.open("/dev/tty", os.O_RDWR | os.O_NOCTTY);
+ if fd >= 0:
+ os.close(fd)
+ raise ExceptionPexpect, "Error! We are not disconnected from a controlling tty."
+ except:
+ # Good! We are disconnected from a controlling tty.
+ pass
+
+ # Verify we can open child pty.
+ fd = os.open(child_name, os.O_RDWR);
+ if fd < 0:
+ raise ExceptionPexpect, "Error! Could not open child pty, " + child_name
+ else:
+ os.close(fd)
+
+ # Verify we now have a controlling tty.
+ fd = os.open("/dev/tty", os.O_WRONLY)
+ if fd < 0:
+ raise ExceptionPexpect, "Error! Could not open controlling tty, /dev/tty"
+ else:
+ os.close(fd)
+
+ def fileno (self): # File-like object.
+
+ """This returns the file descriptor of the pty for the child.
+ """
+
+ return self.child_fd
+
+ def close (self, force=True): # File-like object.
+
+ """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). """
+
+ if not self.closed:
+ self.flush()
+ os.close (self.child_fd)
+ time.sleep(self.delayafterclose) # Give kernel time to update process status.
+ if self.isalive():
+ if not self.terminate(force):
+ raise ExceptionPexpect ('close() could not terminate the child using terminate()')
+ self.child_fd = -1
+ self.closed = True
+ #self.pid = None
+
+ def flush (self): # File-like object.
+
+ """This does nothing. It is here to support the interface for a
+ File-like object. """
+
+ pass
+
+ def isatty (self): # File-like object.
+
+ """This returns True if the file descriptor is open and connected to a
+ tty(-like) device, else False. """
+
+ 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 is None then this method to block forever 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(). """
+
+ attr = termios.tcgetattr(self.child_fd)
+ if attr[3] & termios.ECHO:
+ return True
+ return False
+
+ 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')
+ p.sendline ('1234') # We will see this twice (once from tty echo and again from cat).
+ p.expect (['1234'])
+ p.expect (['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 (['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') # We will see this twice (once from tty echo and again from cat).
+ 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'])
+ """
+
+ self.child_fd
+ attr = termios.tcgetattr(self.child_fd)
+ if state:
+ attr[3] = attr[3] | termios.ECHO
+ else:
+ attr[3] = attr[3] & ~termios.ECHO
+ # I tried TCSADRAIN and TCSAFLUSH, but these were inconsistent
+ # and blocked on some platforms. TCSADRAIN is probably ideal if it worked.
+ termios.tcsetattr(self.child_fd, termios.TCSANOW, attr)
+
+ 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 was 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 in read_nonblocking().')
+
+ 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():
+ r,w,e = self.__select([self.child_fd], [], [], 0) # timeout of 0 means "poll"
+ if not r:
+ self.flag_eof = True
+ raise EOF ('End Of File (EOF) in read_nonblocking(). Braindead platform.')
+ elif self.__irix_hack:
+ # This is a hack for Irix. It seems that Irix requires a long delay before checking isalive.
+ # This adds a 2 second delay, but only when the child is terminated.
+ 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) in read_nonblocking(). Pokey 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;
+ # then timeout on the select; and then finally admit that they are not alive.
+ self.flag_eof = True
+ raise EOF ('End of File (EOF) in read_nonblocking(). Very pokey platform.')
+ else:
+ raise TIMEOUT ('Timeout exceeded in read_nonblocking().')
+
+ if self.child_fd in r:
+ try:
+ s = os.read(self.child_fd, size)
+ except OSError, e: # Linux does this
+ self.flag_eof = True
+ raise EOF ('End Of File (EOF) in read_nonblocking(). Exception style platform.')
+ if s == '': # BSD style
+ self.flag_eof = True
+ raise EOF ('End Of File (EOF) in read_nonblocking(). Empty string style platform.')
+
+ if self.logfile is not None:
+ self.logfile.write (s)
+ self.logfile.flush()
+ if self.logfile_read is not None:
+ self.logfile_read.write (s)
+ self.logfile_read.flush()
+
+ return s
+
+ raise ExceptionPexpect ('Reached an unexpected state in read_nonblocking().')
+
+ def read (self, size = -1): # File-like object.
+
+ """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 ''
+ if size < 0:
+ self.expect (self.delimiter) # delimiter default is EOF
+ 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('.{%d}' % size, re.DOTALL)
+ index = self.expect ([cre, self.delimiter]) # delimiter default is EOF
+ if index == 0:
+ return self.after ### self.before should be ''. Should I assert this?
+ return self.before
+
+ def readline (self, size = -1): # File-like object.
+
+ """This reads and returns one entire line. A trailing newline is kept
+ in the string, but may be absent when a file ends with an incomplete
+ line. Note: This readline() looks for a \\r\\n pair even on UNIX
+ because this is what the pseudo tty device returns. So contrary to what
+ you may expect you will receive the newline as \\r\\n. An empty string
+ is returned when EOF is hit immediately. Currently, the size argument is
+ mostly ignored, so this behavior is not standard for a file-like
+ object. If size is 0 then an empty string is returned. """
+
+ if size == 0:
+ return ''
+ index = self.expect (['\r\n', self.delimiter]) # delimiter default is EOF
+ if index == 0:
+ return self.before + '\r\n'
+ else:
+ return self.before
+
+ def __iter__ (self): # File-like object.
+
+ """This is to support iterators over a file-like object.
+ """
+
+ return self
+
+ def next (self): # File-like object.
+
+ """This is to support iterators over a file-like object.
+ """
+
+ result = self.readline()
+ if result == "":
+ raise StopIteration
+ return result
+
+ def readlines (self, sizehint = -1): # File-like object.
+
+ """This reads until EOF using readline() and returns a list containing
+ the lines thus read. The optional "sizehint" argument is ignored. """
+
+ lines = []
+ while True:
+ line = self.readline()
+ if not line:
+ break
+ lines.append(line)
+ return lines
+
+ def write(self, s): # File-like object.
+
+ """This is similar to send() except that there is no return value.
+ """
+
+ self.send (s)
+
+ def writelines (self, sequence): # File-like object.
+
+ """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):
+
+ """This sends a string to the child process. This returns the number of
+ bytes written. If a log file was set then the data is also written to
+ the log. """
+
+ time.sleep(self.delaybeforesend)
+ if self.logfile is not None:
+ self.logfile.write (s)
+ self.logfile.flush()
+ if self.logfile_send is not None:
+ self.logfile_send.write (s)
+ self.logfile_send.flush()
+ c = os.write(self.child_fd, s)
+ return c
+
+ def sendline(self, s=''):
+
+ """This is like send(), but it adds a line feed (os.linesep). This
+ returns the number of bytes written. """
+
+ n = self.send(s)
+ n = n + self.send (os.linesep)
+ return n
+
+ def sendcontrol(self, char):
+
+ """This sends a control character to the child such as Ctrl-C or
+ Ctrl-D. For example, to send a Ctrl-G (ASCII 7)::
+
+ 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 (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 (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. """
+
+ ### Hmmm... how do I send an EOF?
+ ###C if ((m = write(pty, *buf, p - *buf)) < 0)
+ ###C return (errno == EWOULDBLOCK) ? n : -1;
+ #fd = sys.stdin.fileno()
+ #old = termios.tcgetattr(fd) # remember current state
+ #attr = termios.tcgetattr(fd)
+ #attr[3] = attr[3] | termios.ICANON # ICANON must be set to recognize EOF
+ #try: # use try/finally to ensure state gets restored
+ # termios.tcsetattr(fd, termios.TCSADRAIN, attr)
+ # if hasattr(termios, 'CEOF'):
+ # os.write (self.child_fd, '%c' % termios.CEOF)
+ # else:
+ # # Silly platform does not define CEOF so assume CTRL-D
+ # os.write (self.child_fd, '%c' % 4)
+ #finally: # restore state
+ # termios.tcsetattr(fd, termios.TCSADRAIN, old)
+ if hasattr(termios, 'VEOF'):
+ char = termios.tcgetattr(self.child_fd)[6][termios.VEOF]
+ else:
+ # platform does not define VEOF so assume CTRL-D
+ char = chr(4)
+ self.send(char)
+
+ def sendintr(self):
+
+ """This sends a SIGINT to the child. It does not require
+ the SIGINT to be the first character on a line. """
+
+ if hasattr(termios, 'VINTR'):
+ char = termios.tcgetattr(self.child_fd)[6][termios.VINTR]
+ else:
+ # platform does not define VINTR so assume CTRL-C
+ char = chr(3)
+ self.send (char)
+
+ 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, e:
+ # 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, technically, the child
+ is still alive until its output is read. """
+
+ if self.isalive():
+ pid, status = os.waitpid(self.pid, 0)
+ else:
+ raise ExceptionPexpect ('Cannot wait for dead child process.')
+ self.exitstatus = os.WEXITSTATUS(status)
+ if os.WIFEXITED (status):
+ self.status = status
+ self.exitstatus = os.WEXITSTATUS(status)
+ self.signalstatus = None
+ self.terminated = True
+ elif os.WIFSIGNALED (status):
+ self.status = status
+ self.exitstatus = None
+ self.signalstatus = os.WTERMSIG(status)
+ self.terminated = True
+ elif os.WIFSTOPPED (status):
+ raise ExceptionPexpect ('Wait was called for a child process that is stopped. This is not supported. Is some other process attempting job control with our child pid?')
+ return self.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. """
+
+ if self.terminated:
+ return False
+
+ if self.flag_eof:
+ # This is for Linux, which requires the blocking form of waitpid to get
+ # status of a defunct process. This is super-lame. The flag_eof would have
+ # been set in read_nonblocking(), so this should be safe.
+ waitpid_options = 0
+ else:
+ waitpid_options = os.WNOHANG
+
+ try:
+ pid, status = os.waitpid(self.pid, waitpid_options)
+ except OSError, e: # No child processes
+ if e[0] == errno.ECHILD:
+ raise ExceptionPexpect ('isalive() encountered condition where "terminated" is 0, but there was no child process. Did someone else call waitpid() on our process?')
+ else:
+ raise e
+
+ # I have to do this twice for Solaris. I can't even believe that I figured this out...
+ # If waitpid() returns 0 it means that no child process wishes to
+ # report, and the value of status is undefined.
+ if pid == 0:
+ try:
+ pid, status = os.waitpid(self.pid, waitpid_options) ### os.WNOHANG) # Solaris!
+ except OSError, e: # This should never happen...
+ if e[0] == errno.ECHILD:
+ raise ExceptionPexpect ('isalive() encountered condition that should never happen. There was no child process. Did someone else call waitpid() on our process?')
+ else:
+ raise e
+
+ # If pid is still 0 after two calls to waitpid() then
+ # the process really is alive. This seems to work on all platforms, except
+ # for Irix which seems to require a blocking call on waitpid or select, so I let read_nonblocking
+ # take care of this situation (unfortunately, this requires waiting through the timeout).
+ if pid == 0:
+ return True
+
+ if pid == 0:
+ return True
+
+ if os.WIFEXITED (status):
+ self.status = status
+ self.exitstatus = os.WEXITSTATUS(status)
+ self.signalstatus = None
+ self.terminated = True
+ elif os.WIFSIGNALED (status):
+ self.status = status
+ self.exitstatus = None
+ self.signalstatus = os.WTERMSIG(status)
+ self.terminated = True
+ elif os.WIFSTOPPED (status):
+ raise ExceptionPexpect ('isalive() encountered condition where child process is stopped. This is not supported. Is some other process attempting job control with our child pid?')
+ return False
+
+ 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 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(clp, timeout)
+ ...
+ """
+
+ if patterns is None:
+ return []
+ if type(patterns) is not types.ListType:
+ patterns = [patterns]
+
+ compile_flags = re.DOTALL # Allow dot to match \n
+ if self.ignorecase:
+ compile_flags = compile_flags | re.IGNORECASE
+ compiled_pattern_list = []
+ for p in patterns:
+ if type(p) in types.StringTypes:
+ 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 type(p) is type(re.compile('')):
+ compiled_pattern_list.append(p)
+ else:
+ raise TypeError ('Argument must be one of StringTypes, EOF, TIMEOUT, SRE_Pattern, or a list of those type. %s' % str(type(p)))
+
+ return compiled_pattern_list
+
+ def expect(self, pattern, timeout = -1, searchwindowsize=None):
+
+ """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().
+ """
+
+ compiled_pattern_list = self.compile_pattern_list(pattern)
+ return self.expect_list(compiled_pattern_list, timeout, searchwindowsize)
+
+ def expect_list(self, pattern_list, timeout = -1, searchwindowsize = -1):
+
+ """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. """
+
+ return self.expect_loop(searcher_re(pattern_list), timeout, searchwindowsize)
+
+ def expect_exact(self, pattern_list, timeout = -1, searchwindowsize = -1):
+
+ """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."""
+
+ if type(pattern_list) in types.StringTypes or pattern_list in (TIMEOUT, EOF):
+ pattern_list = [pattern_list]
+ return self.expect_loop(searcher_string(pattern_list), timeout, searchwindowsize)
+
+ 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. """
+
+ self.searcher = searcher
+
+ if timeout == -1:
+ timeout = self.timeout
+ if timeout is not None:
+ end_time = time.time() + timeout
+ if searchwindowsize == -1:
+ searchwindowsize = self.searchwindowsize
+
+ try:
+ incoming = self.buffer
+ freshlen = len(incoming)
+ while True: # Keep reading until exception or return.
+ index = searcher.search(incoming, freshlen, searchwindowsize)
+ if index >= 0:
+ self.buffer = incoming[searcher.end : ]
+ self.before = incoming[ : searcher.start]
+ self.after = incoming[searcher.start : searcher.end]
+ self.match = searcher.match
+ self.match_index = index
+ return self.match_index
+ # No match at this point
+ if timeout < 0 and timeout is not None:
+ raise TIMEOUT ('Timeout exceeded in expect_any().')
+ # Still have time left, so read more data
+ c = self.read_nonblocking (self.maxread, timeout)
+ freshlen = len(c)
+ time.sleep (0.0001)
+ incoming = incoming + c
+ if timeout is not None:
+ timeout = end_time - time.time()
+ except EOF, e:
+ self.buffer = ''
+ self.before = incoming
+ self.after = EOF
+ index = searcher.eof_index
+ if index >= 0:
+ self.match = EOF
+ self.match_index = index
+ return self.match_index
+ else:
+ self.match = None
+ self.match_index = None
+ raise EOF (str(e) + '\n' + str(self))
+ except TIMEOUT, e:
+ self.buffer = incoming
+ self.before = incoming
+ self.after = TIMEOUT
+ index = searcher.timeout_index
+ if index >= 0:
+ self.match = TIMEOUT
+ self.match_index = index
+ return self.match_index
+ else:
+ self.match = None
+ self.match_index = None
+ raise TIMEOUT (str(e) + '\n' + str(self))
+ except:
+ self.before = incoming
+ self.after = None
+ self.match = None
+ self.match_index = None
+ raise
+
+ def getwinsize(self):
+
+ """This returns the terminal window size of the child tty. The return
+ value is a tuple of (rows, cols). """
+
+ TIOCGWINSZ = getattr(termios, 'TIOCGWINSZ', 1074295912L)
+ s = struct.pack('HHHH', 0, 0, 0, 0)
+ x = fcntl.ioctl(self.fileno(), TIOCGWINSZ, s)
+ return struct.unpack('HHHH', x)[0:2]
+
+ def setwinsize(self, r, c):
+
+ """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. """
+
+ # Check for buggy platforms. Some Python versions on some platforms
+ # (notably OSF1 Alpha and RedHat 7.1) truncate the value for
+ # termios.TIOCSWINSZ. It is not clear why this happens.
+ # These platforms don't seem to handle the signed int very well;
+ # yet other platforms like OpenBSD have a large negative value for
+ # TIOCSWINSZ and they don't have a truncate problem.
+ # Newer versions of Linux have totally different values for TIOCSWINSZ.
+ # Note that this fix is a hack.
+ TIOCSWINSZ = getattr(termios, 'TIOCSWINSZ', -2146929561)
+ if TIOCSWINSZ == 2148037735L: # L is not required in Python >= 2.2.
+ TIOCSWINSZ = -2146929561 # Same bits, but with sign.
+ # Note, assume ws_xpixel and ws_ypixel are zero.
+ s = struct.pack('HHHH', r, c, 0, 0)
+ fcntl.ioctl(self.fileno(), TIOCSWINSZ, s)
+
+ 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])
+ p = pexpect.spawn('/bin/bash') # Note this is global and used in sigwinch_passthrough.
+ signal.signal(signal.SIGWINCH, sigwinch_passthrough)
+ p.interact()
+ """
+
+ # Flush the buffer.
+ self.stdout.write (self.buffer)
+ self.stdout.flush()
+ self.buffer = ''
+ mode = tty.tcgetattr(self.STDIN_FILENO)
+ tty.setraw(self.STDIN_FILENO)
+ 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 != '' 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:
+ data = self.__interact_read(self.child_fd)
+ 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, e:
+ if e[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 really is an exception
+ raise
+
+##############################################################################
+# The following methods are no longer supported or allowed.
+
+ def setmaxread (self, maxread):
+
+ """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):
+
+ """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 searcher_string (object):
+
+ """This is a plain string search helper for the spawn.expect_any() method.
+
+ 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 zip(range(len(strings)), 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 = 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. """
+
+ absurd_match = len(buffer)
+ first_match = absurd_match
+
+ # '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 n < first_match:
+ first_match = n
+ best_index, best_match = index, s
+ if first_match == absurd_match:
+ 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.
+
+ 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(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,str(s.pattern))) for n,s in self._searches]
+ 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 = 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."""
+
+ absurd_match = len(buffer)
+ first_match = absurd_match
+ # '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 n < first_match:
+ first_match = n
+ the_match = match
+ best_index = index
+ if first_match == absurd_match:
+ return -1
+ self.start = first_match
+ self.match = the_match
+ self.end = self.match.end()
+ return best_index
+
+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 already contains a path.
+ if os.path.dirname(filename) != '':
+ if os.access (filename, os.X_OK):
+ return filename
+
+ if not os.environ.has_key('PATH') or os.environ['PATH'] == '':
+ p = os.defpath
+ else:
+ p = os.environ['PATH']
+
+ # Oddly enough this was the one line that made Pexpect
+ # incompatible with Python 1.5.2.
+ #pathlist = p.split (os.pathsep)
+ pathlist = string.split (p, os.pathsep)
+
+ for path in pathlist:
+ f = os.path.join(path, filename)
+ if os.access(f, os.X_OK):
+ return f
+ 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
+ state_whitespace = 4 # The state of consuming whitespace between commands.
+ 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:
+ None # Do nothing.
+ 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
+
+# vi:ts=4:sw=4:expandtab:ft=python:
+
projects / ussd-widget / commitdiff
