| """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 |
| (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) 2006 Noah Spurrier |
| http://pexpect.sourceforge.net/ |
| |
| $Revision$ |
| $Date$ |
| """ |
| 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__ = '2.1' |
| __revision__ = '$Revision$' |
| __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 = traceback.format_list(tblist) |
| return ''.join(tblist) |
| def __filter_not_pexpect(self, trace_list_item): |
| 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. |
| """ |
| 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): |
| """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, which you may |
| or may not find simpler: |
| 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. |
| 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) |
| else: |
| child = spawn(command, timeout=timeout, maxread=2000, logfile=logfile) |
| 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) is types.StringType: |
| 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]) is types.StringType: |
| child.send(responses[index]) |
| elif type(responses[index]) is types.FunctionType: |
| callback_result = responses[index](locals()) |
| sys.stdout.flush() |
| if type(callback_result) is types.StringType: |
| 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, 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: |
| p = pexpect.spawn ('/usr/bin/ftp') |
| p = pexpect.spawn ('/usr/bin/ssh user@example.com') |
| p = pexpect.spawn ('ls -latr /tmp') |
| You may also construct it with a list of arguments like so: |
| p = pexpect.spawn ('/usr/bin/ftp', []) |
| p = pexpect.spawn ('/usr/bin/ssh', ['user@example.com']) |
| p = 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(). |
| |
| 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. |
| Seeting 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 1: |
| child = pexpect.spawn('some_command') |
| fout = file('mylog.txt','w') |
| child.logfile = fout |
| Example 2: |
| child = pexpect.spawn('some_command') |
| child.logfile = sys.stdout |
| |
| 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 heyboard. 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. |
| 1/10th of a second (100 ms) seems to be enough to clear up the problem. |
| You can set delaybeforesend to 0 to return to the old behavior. |
| |
| Note that spawn is clever about finding commands on your path. |
| It uses the same logic that "which" uses to find executables. |
| |
| If you wish to get the exit status of the child you must call |
| the close() method. The exit or signal status of the child will be |
| stored in self.exitstatus or self.signalstatus. |
| If the child exited normally then exitstatus will store the exit return code and |
| signalstatus will be None. |
| If the child was terminated abnormally with a signal then signalstatus will store |
| the signal value and exitstatus will be None. |
| 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.patterns = 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.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. |
| self.delaybeforesend = 0.1 # Sets sleep time used just before sending data to child. |
| self.delayafterclose = 0.1 # Sets delay in close() method to allow kernel time to update process status. |
| self.delayafterterminate = 0.1 # Sets delay in terminate() method to allow kernel time to update process status. |
| 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.env = env |
| self.__irix_hack = sys.platform.lower().find('irix') >= 0 # This flags if we are running on irix |
| self.use_native_pty_fork = not (sys.platform.lower().find('solaris') >= 0) # Solaris uses internal __fork_pty(). All other use pty.fork(). |
| |
| # 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>' |
| return |
| |
| # 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) + '>' |
| self.__spawn() |
| |
| 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: |
| self.close() |
| |
| def __str__(self): |
| """This returns the current state of the pexpect object as a string. |
| """ |
| s = [] |
| s.append(repr(self)) |
| s.append('version: ' + __version__ + ' (' + __revision__ + ')') |
| s.append('command: ' + str(self.command)) |
| s.append('args: ' + str(self.args)) |
| if self.patterns is None: |
| s.append('patterns: None') |
| else: |
| s.append('patterns:') |
| for p in self.patterns: |
| if type(p) is type(re.compile('')): |
| s.append(' ' + str(p.pattern)) |
| else: |
| s.append(' ' + str(p)) |
| 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('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): |
| """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__. |
| """ |
| # 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. |
| |
| 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.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) |
| self.child_fd = -1 |
| self.closed = True |
| 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()') |
| |
| 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 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 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 |
| new = termios.tcgetattr(self.child_fd) |
| if state: |
| new[3] = new[3] | termios.ECHO |
| else: |
| new[3] = new[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, new) |
| |
| 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==None then the read may block indefinitely. |
| If timeout==-1 then the self.timeout value is used. |
| If timeout==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 a 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() |
| |
| 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 agument 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, str): # File-like object. |
| """This is similar to send() except that there is no return value. |
| """ |
| self.send (str) |
| |
| 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 str in sequence: |
| self.write (str) |
| |
| def send(self, str): |
| """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 (str) |
| self.logfile.flush() |
| c = os.write(self.child_fd, str) |
| return c |
| |
| def sendline(self, str=''): |
| """This is like send(), but it adds a line feed (os.linesep). |
| This returns the number of bytes written. |
| """ |
| n = self.send(str) |
| n = n + self.send (os.linesep) |
| return n |
| |
| def sendeof(self): |
| """This sends an EOF to the child. |
| This sends a character which causes the pending parent output |
| buffer to be sent to the waiting child program without |
| waiting for end-of-line. If it is the first character of the |
| line, the read() in the user program returns 0, which |
| signifies end-of-file. This means to work as expected |
| a sendeof() has to be called at the begining 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 |
| new = termios.tcgetattr(fd) |
| new[3] = new[3] | termios.ICANON # ICANON must be set to recognize EOF |
| try: # use try/finally to ensure state gets restored |
| termios.tcsetattr(fd, termios.TCSADRAIN, new) |
| if 'CEOF' in dir(termios): |
| os.write (self.child_fd, '%c' % termios.CEOF) |
| else: |
| os.write (self.child_fd, '%c' % 4) # Silly platform does not define CEOF so assume CTRL-D |
| finally: # restore state |
| termios.tcsetattr(fd, termios.TCSADRAIN, old) |
| |
| 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 |
| 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 |
| #raise ExceptionPexpect ('terminate() could not terminate child process. Try terminate(force=True)?') |
| |
| 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. |
| |
| 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(clp, 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) is types.StringType: |
| 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 StringType, 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 including a list. |
| The pattern can be a StringType, EOF, a compiled re, or a list 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. |
| |
| 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 occured 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. |
| |
| Note: 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. |
| """ |
| |
| self.patterns = pattern_list |
| |
| 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 |
| while True: # Keep reading until exception or return. |
| # Sequence through the list of patterns looking for a match. |
| first_match = -1 |
| for cre in pattern_list: |
| if cre is EOF or cre is TIMEOUT: |
| continue # The patterns for PexpectExceptions are handled differently. |
| if searchwindowsize is None: # search everything |
| match = cre.search(incoming) |
| else: |
| startpos = max(0, len(incoming) - searchwindowsize) |
| match = cre.search(incoming, startpos) |
| if match is None: |
| continue |
| if first_match > match.start() or first_match == -1: |
| first_match = match.start() |
| self.match = match |
| self.match_index = pattern_list.index(cre) |
| if first_match > -1: |
| self.buffer = incoming[self.match.end() : ] |
| self.before = incoming[ : self.match.start()] |
| self.after = incoming[self.match.start() : self.match.end()] |
| return self.match_index |
| # No match at this point |
| if timeout < 0 and timeout is not None: |
| raise TIMEOUT ('Timeout exceeded in expect_list().') |
| # Still have time left, so read more data |
| c = self.read_nonblocking (self.maxread, timeout) |
| 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 |
| if EOF in pattern_list: |
| self.match = EOF |
| self.match_index = pattern_list.index(EOF) |
| return self.match_index |
| else: |
| self.match = None |
| self.match_index = None |
| raise EOF (str(e) + '\n' + str(self)) |
| except TIMEOUT, e: |
| self.before = incoming |
| self.after = TIMEOUT |
| if TIMEOUT in pattern_list: |
| self.match = TIMEOUT |
| self.match_index = pattern_list.index(TIMEOUT) |
| return self.match_index |
| else: |
| self.match = None |
| self.match_index = None |
| raise TIMEOUT (str(e) + '\n' + str(self)) |
| except Exception: |
| 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). |
| """ |
| if 'TIOCGWINSZ' in dir(termios): |
| TIOCGWINSZ = termios.TIOCGWINSZ |
| else: |
| TIOCGWINSZ = 1074295912L # assume if not defined |
| 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. |
| if 'TIOCSWINSZ' in dir(termios): |
| TIOCSWINSZ = termios.TIOCSWINSZ |
| else: |
| 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 expect_exact (self, pattern_list, timeout = -1): |
| """This method is no longer supported or allowed. |
| It was too hard to maintain and keep it up to date with expect_list. |
| Few people used this method. Most people favored reliability over speed. |
| The implementation is left in comments in case anyone needs to hack this |
| feature back into their copy. |
| If someone wants to diff this with expect_list and make them work |
| nearly the same then I will consider adding this make in. |
| """ |
| raise ExceptionPexpect ('This method is no longer supported or allowed.') |
| 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 |
| ############################################################################## |
| |
| 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 |
| |