| """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: |