[sanitizer] Improve FreeBSD ASLR detection
[llvm-project.git] / lldb / third_party / Python / module / pexpect-4.6 / pexpect / fdpexpect.py
blobcddd50e10058a8b65b57c3d5bb2724fb35a22c2a
1 '''This is like pexpect, but it will work with any file descriptor that you
2 pass it. You are responsible for opening and close the file descriptor.
3 This allows you to use Pexpect with sockets and named pipes (FIFOs).
5 PEXPECT LICENSE
7 This license is approved by the OSI and FSF as GPL-compatible.
8 http://opensource.org/licenses/isc-license.txt
10 Copyright (c) 2012, Noah Spurrier <noah@noah.org>
11 PERMISSION TO USE, COPY, MODIFY, AND/OR DISTRIBUTE THIS SOFTWARE FOR ANY
12 PURPOSE WITH OR WITHOUT FEE IS HEREBY GRANTED, PROVIDED THAT THE ABOVE
13 COPYRIGHT NOTICE AND THIS PERMISSION NOTICE APPEAR IN ALL COPIES.
14 THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
15 WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
16 MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
17 ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
18 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
19 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
20 OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
22 '''
24 from .spawnbase import SpawnBase
25 from .exceptions import ExceptionPexpect, TIMEOUT
26 from .utils import select_ignore_interrupts, poll_ignore_interrupts
27 import os
29 __all__ = ['fdspawn']
31 class fdspawn(SpawnBase):
32 '''This is like pexpect.spawn but allows you to supply your own open file
33 descriptor. For example, you could use it to read through a file looking
34 for patterns, or to control a modem or serial device. '''
36 def __init__ (self, fd, args=None, timeout=30, maxread=2000, searchwindowsize=None,
37 logfile=None, encoding=None, codec_errors='strict', use_poll=False):
38 '''This takes a file descriptor (an int) or an object that support the
39 fileno() method (returning an int). All Python file-like objects
40 support fileno(). '''
42 if type(fd) != type(0) and hasattr(fd, 'fileno'):
43 fd = fd.fileno()
45 if type(fd) != type(0):
46 raise ExceptionPexpect('The fd argument is not an int. If this is a command string then maybe you want to use pexpect.spawn.')
48 try: # make sure fd is a valid file descriptor
49 os.fstat(fd)
50 except OSError:
51 raise ExceptionPexpect('The fd argument is not a valid file descriptor.')
53 self.args = None
54 self.command = None
55 SpawnBase.__init__(self, timeout, maxread, searchwindowsize, logfile,
56 encoding=encoding, codec_errors=codec_errors)
57 self.child_fd = fd
58 self.own_fd = False
59 self.closed = False
60 self.name = '<file descriptor %d>' % fd
61 self.use_poll = use_poll
63 def close (self):
64 """Close the file descriptor.
66 Calling this method a second time does nothing, but if the file
67 descriptor was closed elsewhere, :class:`OSError` will be raised.
68 """
69 if self.child_fd == -1:
70 return
72 self.flush()
73 os.close(self.child_fd)
74 self.child_fd = -1
75 self.closed = True
77 def isalive (self):
78 '''This checks if the file descriptor is still valid. If :func:`os.fstat`
79 does not raise an exception then we assume it is alive. '''
81 if self.child_fd == -1:
82 return False
83 try:
84 os.fstat(self.child_fd)
85 return True
86 except:
87 return False
89 def terminate (self, force=False): # pragma: no cover
90 '''Deprecated and invalid. Just raises an exception.'''
91 raise ExceptionPexpect('This method is not valid for file descriptors.')
93 # These four methods are left around for backwards compatibility, but not
94 # documented as part of fdpexpect. You're encouraged to use os.write
95 # directly.
96 def send(self, s):
97 "Write to fd, return number of bytes written"
98 s = self._coerce_send_string(s)
99 self._log(s, 'send')
101 b = self._encoder.encode(s, final=False)
102 return os.write(self.child_fd, b)
104 def sendline(self, s):
105 "Write to fd with trailing newline, return number of bytes written"
106 s = self._coerce_send_string(s)
107 return self.send(s + self.linesep)
109 def write(self, s):
110 "Write to fd, return None"
111 self.send(s)
113 def writelines(self, sequence):
114 "Call self.write() for each item in sequence"
115 for s in sequence:
116 self.write(s)
118 def read_nonblocking(self, size=1, timeout=-1):
120 Read from the file descriptor and return the result as a string.
122 The read_nonblocking method of :class:`SpawnBase` assumes that a call
123 to os.read will not block (timeout parameter is ignored). This is not
124 the case for POSIX file-like objects such as sockets and serial ports.
126 Use :func:`select.select`, timeout is implemented conditionally for
127 POSIX systems.
129 :param int size: Read at most *size* bytes.
130 :param int timeout: Wait timeout seconds for file descriptor to be
131 ready to read. When -1 (default), use self.timeout. When 0, poll.
132 :return: String containing the bytes read
134 if os.name == 'posix':
135 if timeout == -1:
136 timeout = self.timeout
137 rlist = [self.child_fd]
138 wlist = []
139 xlist = []
140 if self.use_poll:
141 rlist = poll_ignore_interrupts(rlist, timeout)
142 else:
143 rlist, wlist, xlist = select_ignore_interrupts(
144 rlist, wlist, xlist, timeout
146 if self.child_fd not in rlist:
147 raise TIMEOUT('Timeout exceeded.')
148 return super(fdspawn, self).read_nonblocking(size)