+++ /dev/null
-"""Pexpect is a Python module for spawning child applications and controlling
-them automatically. Pexpect can be used for automating interactive applications
-such as ssh, ftp, passwd, telnet, etc. It can be used to a automate setup
-scripts for duplicating software package installations on different servers. It
-can be used for automated software testing. Pexpect is in the spirit of Don
-Libes' Expect, but Pexpect is pure Python. Other Expect-like modules for Python
-require TCL and Expect or require C extensions to be compiled. Pexpect does not
-use C, Expect, or TCL extensions. It should work on any platform that supports
-the standard Python pty module. The Pexpect interface focuses on ease of use so
-that simple tasks are easy.
-
-There are two main interfaces to Pexpect -- the function, run() and the class,
-spawn. You can call the run() function to execute a command and return the
-output. This is a handy replacement for os.system().
-
-For example:
- pexpect.run('ls -la')
-
-The more powerful interface is the spawn class. You can use this to spawn an
-external child command and then interact with the child by sending lines and
-expecting responses.
-
-For example:
- child = pexpect.spawn('scp foo myname@host.example.com:.')
- child.expect ('Password:')
- child.sendline (mypassword)
-
-This works even for commands that ask for passwords or other input outside of
-the normal stdio streams.
-
-Credits:
-Noah Spurrier, Richard Holden, Marco Molteni, Kimberley Burchett, Robert Stone,
-Hartmut Goebel, Chad Schroeder, Erick Tryzelaar, Dave Kirby, Ids vander Molen,
-George Todd, Noel Taylor, Nicolas D. Cesar, Alexander Gattin,
-Geoffrey Marshall, Francisco Lourenco, Glen Mabey, Karthik Gurusamy,
-Fernando Perez
-(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: 395 $
-$Date: 2006-05-31 20:07:18 -0700 (Wed, 31 May 2006) $
-"""
-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: 395 $'
-__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().
- self.allstr = ""
-
- # 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()]
- #print "MATCH--", self.after, "--EOM"
- 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
- self.allstr += c
- #print "INCOMING--", c, "--EOI"
- 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
-
git://git.onelab.eu / monitor.git / blobdiff