def Pipe(duplex=True):
'''
Returns pair of connection objects at either end of a pipe
'''
if duplex:
s1, s2 = socket.socketpair()
c1 = _multiprocessing.Connection(os.dup(s1.fileno()))
c2 = _multiprocessing.Connection(os.dup(s2.fileno()))
s1.close()
s2.close()
else:
fd1, fd2 = os.pipe()
c1 = _multiprocessing.Connection(fd1, writable=False)
c2 = _multiprocessing.Connection(fd2, readable=False)
return c1, c2
python类dup()的实例源码
def __init__(self, fh, map=None, maxdata=None, ignore_broken_pipe=False, logger=None, **obsopt):
"""Wrap a dispatcher around the passed filehandle.
If `ignore_broken_pipe` is `True`, an `EPIPE` or `EBADF` error will
call `handle_close()` instead of `handle_expt()`. Useful when broken
pipes should be handled quietly.
`logger` is a logger which will be used to log unusual exceptions;
otherwise, they will be printed to stderr.
"""
self.maxdata = maxdata if maxdata else self.pipe_maxdata
self.__logger = logger
if ignore_broken_pipe:
self.__ignore_errno = [EPIPE, EBADF]
else:
self.__ignore_errno = []
self.__filehandle = fh
# Check for overduplication of the file descriptor and close the extra
fddup = os.dup(fh.fileno())
file_dispatcher.__init__(self, fddup, map=map)
if (self._fileno != fddup): os.close (fddup)
Observable.__init__(self, **obsopt)
def __init__(self, targetfd, tmpfile=None, now=True, patchsys=False):
""" save targetfd descriptor, and open a new
temporary file there. If no tmpfile is
specified a tempfile.Tempfile() will be opened
in text mode.
"""
self.targetfd = targetfd
if tmpfile is None and targetfd != 0:
f = tempfile.TemporaryFile('wb+')
tmpfile = dupfile(f, encoding="UTF-8")
f.close()
self.tmpfile = tmpfile
self._savefd = os.dup(self.targetfd)
if patchsys:
self._oldsys = getattr(sys, patchsysdict[targetfd])
if now:
self.start()
def safe_text_dupfile(f, mode, default_encoding="UTF8"):
""" return a open text file object that's a duplicate of f on the
FD-level if possible.
"""
encoding = getattr(f, "encoding", None)
try:
fd = f.fileno()
except Exception:
if "b" not in getattr(f, "mode", "") and hasattr(f, "encoding"):
# we seem to have a text stream, let's just use it
return f
else:
newfd = os.dup(fd)
if "b" not in mode:
mode += "b"
f = os.fdopen(newfd, mode, 0) # no buffering
return EncodedFile(f, encoding or default_encoding)
def Pipe(duplex=True):
'''
Returns pair of connection objects at either end of a pipe
'''
if duplex:
s1, s2 = socket.socketpair()
s1.setblocking(True)
s2.setblocking(True)
c1 = _multiprocessing.Connection(os.dup(s1.fileno()))
c2 = _multiprocessing.Connection(os.dup(s2.fileno()))
s1.close()
s2.close()
else:
fd1, fd2 = os.pipe()
c1 = _multiprocessing.Connection(fd1, writable=False)
c2 = _multiprocessing.Connection(fd2, readable=False)
return c1, c2
def main():
if sys.platform in ['win32', 'cygwin']:
return 0
# This script is called by gclient. gclient opens its hooks subprocesses with
# (stdout=subprocess.PIPE, stderr=subprocess.STDOUT) and then does custom
# output processing that breaks printing '\r' characters for single-line
# updating status messages as printed by curl and wget.
# Work around this by setting stderr of the update.sh process to stdin (!):
# gclient doesn't redirect stdin, and while stdin itself is read-only, a
# dup()ed sys.stdin is writable, try
# fd2 = os.dup(sys.stdin.fileno()); os.write(fd2, 'hi')
# TODO: Fix gclient instead, http://crbug.com/95350
return subprocess.call(
[os.path.join(os.path.dirname(__file__), 'update.sh')] + sys.argv[1:],
stderr=os.fdopen(
os.dup(
sys.stdin.fileno())))
def create_child(*args):
parentfp, childfp = socket.socketpair()
pid = os.fork()
if not pid:
mitogen.core.set_block(childfp.fileno())
os.dup2(childfp.fileno(), 0)
os.dup2(childfp.fileno(), 1)
childfp.close()
parentfp.close()
os.execvp(args[0], args)
childfp.close()
# Decouple the socket from the lifetime of the Python socket object.
fd = os.dup(parentfp.fileno())
parentfp.close()
LOG.debug('create_child() child %d fd %d, parent %d, cmd: %s',
pid, fd, os.getpid(), Argv(args))
return pid, fd
def Pipe(duplex=True):
'''
Returns pair of connection objects at either end of a pipe
'''
if duplex:
s1, s2 = socket.socketpair()
c1 = _multiprocessing.Connection(os.dup(s1.fileno()))
c2 = _multiprocessing.Connection(os.dup(s2.fileno()))
s1.close()
s2.close()
else:
fd1, fd2 = os.pipe()
c1 = _multiprocessing.Connection(fd1, writable=False)
c2 = _multiprocessing.Connection(fd2, readable=False)
return c1, c2
def test_closerange(self):
first = os.open(support.TESTFN, os.O_CREAT|os.O_RDWR)
# We must allocate two consecutive file descriptors, otherwise
# it will mess up other file descriptors (perhaps even the three
# standard ones).
second = os.dup(first)
try:
retries = 0
while second != first + 1:
os.close(first)
retries += 1
if retries > 10:
# XXX test skipped
self.skipTest("couldn't allocate two consecutive fds")
first, second = second, os.dup(second)
finally:
os.close(second)
# close a fd that is open, and one that isn't
os.closerange(first, first + 2)
self.assertRaises(OSError, os.write, first, b"a")
def _mock_output_restore(self):
"""
Mock methods to ensure that stdout and stderr are restored,
after they have been captured.
Return the path to the tempfile that was used to capture the output.
"""
old_stdout = os.dup(1)
old_stderr = os.dup(2)
fd, outfile = tempfile.mkstemp()
mkstemp_patcher = mock.patch("tempfile.mkstemp")
mock_mkstemp = mkstemp_patcher.start()
self.addCleanup(mkstemp_patcher.stop)
mock_mkstemp.return_value = (fd, outfile)
dup_patcher = mock.patch("os.dup")
mock_dup = dup_patcher.start()
self.addCleanup(dup_patcher.stop)
mock_dup.side_effect = lambda fd: {1: old_stdout, 2: old_stderr}[fd]
dup2_patcher = mock.patch("os.dup2", wraps=os.dup2)
mock_dup2 = dup2_patcher.start()
self.addCleanup(dup2_patcher.stop)
return outfile, mock_dup2
def _setup_pipe(self, name):
from fcntl import fcntl, F_GETFL, F_SETFL
real_fd = getattr(sys, '__%s__' % name).fileno()
save_fd = os.dup(real_fd)
self._save_fds[name] = save_fd
pipe_out, pipe_in = os.pipe()
os.dup2(pipe_in, real_fd)
os.close(pipe_in)
self._real_fds[name] = real_fd
# make pipe_out non-blocking
flags = fcntl(pipe_out, F_GETFL)
fcntl(pipe_out, F_SETFL, flags | os.O_NONBLOCK)
return pipe_out
def callSolver(self, lp, callback = None):
"""Solves the problem with yaposib
"""
if self.msg == 0:
#close stdout to get rid of messages
tempfile = open(mktemp(),'w')
savestdout = os.dup(1)
os.close(1)
if os.dup(tempfile.fileno()) != 1:
raise PulpSolverError("couldn't redirect stdout - dup() error")
self.solveTime = -clock()
lp.solverModel.solve(self.mip)
self.solveTime += clock()
if self.msg == 0:
#reopen stdout
os.close(1)
os.dup(savestdout)
os.close(savestdout)
def start_pager():
if not sys.stdout.isatty():
return
pager = get_pager()
if not pager:
return
if "LESS" not in os.environ:
os.environ["LESS"] = "FRSX"
oldstdout = os.dup(1)
global pagerproc
pagerproc = subprocess.Popen([pager],
stdin=subprocess.PIPE,
stdout=oldstdout,
close_fds=True)
os.close(oldstdout)
os.dup2(pagerproc.stdin.fileno(), 1)
def stdchannel_redirected(stdchannel, dest_filename):
"""
A context manager to temporarily redirect stdout or stderr
e.g.:
with stdchannel_redirected(sys.stderr, os.devnull):
if compiler.has_function('clock_gettime', libraries=['rt']):
libraries.append('rt')
Code adapted from https://stackoverflow.com/a/17752455/1382869
"""
try:
oldstdchannel = os.dup(stdchannel.fileno())
dest_file = open(dest_filename, 'w')
os.dup2(dest_file.fileno(), stdchannel.fileno())
yield
finally:
if oldstdchannel is not None:
os.dup2(oldstdchannel, stdchannel.fileno())
if dest_file is not None:
dest_file.close()
def Pipe(duplex=True):
'''
Returns pair of connection objects at either end of a pipe
'''
if duplex:
s1, s2 = socket.socketpair()
s1.setblocking(True)
s2.setblocking(True)
c1 = _multiprocessing.Connection(os.dup(s1.fileno()))
c2 = _multiprocessing.Connection(os.dup(s2.fileno()))
s1.close()
s2.close()
else:
fd1, fd2 = os.pipe()
c1 = _multiprocessing.Connection(fd1, writable=False)
c2 = _multiprocessing.Connection(fd2, readable=False)
return c1, c2
def test_closerange(self):
first = os.open(test_support.TESTFN, os.O_CREAT|os.O_RDWR)
# We must allocate two consecutive file descriptors, otherwise
# it will mess up other file descriptors (perhaps even the three
# standard ones).
second = os.dup(first)
try:
retries = 0
while second != first + 1:
os.close(first)
retries += 1
if retries > 10:
# XXX test skipped
self.skipTest("couldn't allocate two consecutive fds")
first, second = second, os.dup(second)
finally:
os.close(second)
# close a fd that is open, and one that isn't
os.closerange(first, first + 2)
self.assertRaises(OSError, os.write, first, "a")
def Pipe(duplex=True):
'''
Returns pair of connection objects at either end of a pipe
'''
if duplex:
s1, s2 = socket.socketpair()
s1.setblocking(True)
s2.setblocking(True)
c1 = _multiprocessing.Connection(os.dup(s1.fileno()))
c2 = _multiprocessing.Connection(os.dup(s2.fileno()))
s1.close()
s2.close()
else:
fd1, fd2 = os.pipe()
c1 = _multiprocessing.Connection(fd1, writable=False)
c2 = _multiprocessing.Connection(fd2, readable=False)
return c1, c2
def test_closerange(self):
first = os.open(test_support.TESTFN, os.O_CREAT|os.O_RDWR)
# We must allocate two consecutive file descriptors, otherwise
# it will mess up other file descriptors (perhaps even the three
# standard ones).
second = os.dup(first)
try:
retries = 0
while second != first + 1:
os.close(first)
retries += 1
if retries > 10:
# XXX test skipped
self.skipTest("couldn't allocate two consecutive fds")
first, second = second, os.dup(second)
finally:
os.close(second)
# close a fd that is open, and one that isn't
os.closerange(first, first + 2)
self.assertRaises(OSError, os.write, first, "a")
def __init__(self, targetfd, tmpfile=None, now=True, patchsys=False):
""" save targetfd descriptor, and open a new
temporary file there. If no tmpfile is
specified a tempfile.Tempfile() will be opened
in text mode.
"""
self.targetfd = targetfd
if tmpfile is None and targetfd != 0:
f = tempfile.TemporaryFile('wb+')
tmpfile = dupfile(f, encoding="UTF-8")
f.close()
self.tmpfile = tmpfile
self._savefd = os.dup(self.targetfd)
if patchsys:
self._oldsys = getattr(sys, patchsysdict[targetfd])
if now:
self.start()
def safe_text_dupfile(f, mode, default_encoding="UTF8"):
""" return a open text file object that's a duplicate of f on the
FD-level if possible.
"""
encoding = getattr(f, "encoding", None)
try:
fd = f.fileno()
except Exception:
if "b" not in getattr(f, "mode", "") and hasattr(f, "encoding"):
# we seem to have a text stream, let's just use it
return f
else:
newfd = os.dup(fd)
if "b" not in mode:
mode += "b"
f = os.fdopen(newfd, mode, 0) # no buffering
return EncodedFile(f, encoding or default_encoding)
def Pipe(duplex=True):
'''
Returns pair of connection objects at either end of a pipe
'''
if duplex:
s1, s2 = socket.socketpair()
s1.setblocking(True)
s2.setblocking(True)
c1 = _multiprocessing.Connection(os.dup(s1.fileno()))
c2 = _multiprocessing.Connection(os.dup(s2.fileno()))
s1.close()
s2.close()
else:
fd1, fd2 = os.pipe()
c1 = _multiprocessing.Connection(fd1, writable=False)
c2 = _multiprocessing.Connection(fd2, readable=False)
return c1, c2
def __init__(self, stream, filename):
self._stream = stream
self._fd = stream.fileno()
self._filename = filename
# Keep original stream for later
self._uncaptured_fd = os.dup(self._fd)
# Open file to save stream to
cap_fd = os.open(self._filename,
os.O_CREAT | os.O_TRUNC | os.O_WRONLY,
0600)
# Send stream to this file
self._stream.flush()
os.dup2(cap_fd, self._fd)
os.close(cap_fd)
def __init__(self, stream, filename):
self._stream = stream
self._fd = stream.fileno()
self._filename = filename
# Keep original stream for later
self._uncaptured_fd = os.dup(self._fd)
# Open file to save stream to
cap_fd = os.open(self._filename,
os.O_CREAT | os.O_TRUNC | os.O_WRONLY,
0600)
# Send stream to this file
self._stream.flush()
os.dup2(cap_fd, self._fd)
os.close(cap_fd)
def test_closerange(self):
first = os.open(support.TESTFN, os.O_CREAT|os.O_RDWR)
# We must allocate two consecutive file descriptors, otherwise
# it will mess up other file descriptors (perhaps even the three
# standard ones).
second = os.dup(first)
try:
retries = 0
while second != first + 1:
os.close(first)
retries += 1
if retries > 10:
# XXX test skipped
self.skipTest("couldn't allocate two consecutive fds")
first, second = second, os.dup(second)
finally:
os.close(second)
# close a fd that is open, and one that isn't
os.closerange(first, first + 2)
self.assertRaises(OSError, os.write, first, b"a")
def __enter__(self):
assert self._original_fds is None, 'You can only use this object once'
# Save the original FDs and file objects.
# FIXME: How about stdin?
self._original_fds = [(fd, os.dup(fd)) for fd in (1, 2)]
self._old_stdout = sys.stdout
self._old_stderr = sys.stderr
# Redirect the Python file objects.
throwaway_fileno, self._redirected_path = tempfile.mkstemp()
# We need to reopen the file or Python and non-Python will have two different
# positions in the file (and we can't build a file object from a fileno).
os.close(throwaway_fileno)
self._redirected_file = open(self._redirected_path, 'w')
sys.stdout = self._redirected_file
sys.stderr = self._redirected_file
# Redirect the standard FDs.
os.dup2(self._redirected_file.fileno(), 1)
os.dup2(self._redirected_file.fileno(), 2)
return self
def __init__(self, targetfd, tmpfile=None, now=True, patchsys=False):
""" save targetfd descriptor, and open a new
temporary file there. If no tmpfile is
specified a tempfile.Tempfile() will be opened
in text mode.
"""
self.targetfd = targetfd
if tmpfile is None and targetfd != 0:
f = tempfile.TemporaryFile('wb+')
tmpfile = dupfile(f, encoding="UTF-8")
f.close()
self.tmpfile = tmpfile
self._savefd = os.dup(self.targetfd)
if patchsys:
self._oldsys = getattr(sys, patchsysdict[targetfd])
if now:
self.start()
def safe_text_dupfile(f, mode, default_encoding="UTF8"):
""" return a open text file object that's a duplicate of f on the
FD-level if possible.
"""
encoding = getattr(f, "encoding", None)
try:
fd = f.fileno()
except Exception:
if "b" not in getattr(f, "mode", "") and hasattr(f, "encoding"):
# we seem to have a text stream, let's just use it
return f
else:
newfd = os.dup(fd)
if "b" not in mode:
mode += "b"
f = os.fdopen(newfd, mode, 0) # no buffering
return EncodedFile(f, encoding or default_encoding)
def __init__(self, targetfd, tmpfile=None, now=True, patchsys=False):
""" save targetfd descriptor, and open a new
temporary file there. If no tmpfile is
specified a tempfile.Tempfile() will be opened
in text mode.
"""
self.targetfd = targetfd
if tmpfile is None and targetfd != 0:
f = tempfile.TemporaryFile('wb+')
tmpfile = dupfile(f, encoding="UTF-8")
f.close()
self.tmpfile = tmpfile
self._savefd = os.dup(self.targetfd)
if patchsys:
self._oldsys = getattr(sys, patchsysdict[targetfd])
if now:
self.start()
def safe_text_dupfile(f, mode, default_encoding="UTF8"):
""" return a open text file object that's a duplicate of f on the
FD-level if possible.
"""
encoding = getattr(f, "encoding", None)
try:
fd = f.fileno()
except Exception:
if "b" not in getattr(f, "mode", "") and hasattr(f, "encoding"):
# we seem to have a text stream, let's just use it
return f
else:
newfd = os.dup(fd)
if "b" not in mode:
mode += "b"
f = os.fdopen(newfd, mode, 0) # no buffering
return EncodedFile(f, encoding or default_encoding)
def __enter__(self):
self.sys = sys
# save previous stdout/stderr
self.saved_streams = saved_streams = sys.__stdout__, sys.__stderr__
self.fds = fds = [s.fileno() for s in saved_streams]
self.saved_fds = map(os.dup, fds)
# flush any pending output
for s in saved_streams: s.flush()
# open surrogate files
if self.combine:
null_streams = [open(self.outfiles[0], self.mode, 0)] * 2
if self.outfiles[0] != os.devnull:
# disable buffering so output is merged immediately
sys.stdout, sys.stderr = map(os.fdopen, fds, ['w']*2, [0]*2)
else: null_streams = [open(f, self.mode, 0) for f in self.outfiles]
self.null_fds = null_fds = [s.fileno() for s in null_streams]
self.null_streams = null_streams
# overwrite file objects and low-level file descriptors
map(os.dup2, null_fds, fds)
