mirror of
https://github.com/microsoft/PowerToys.git
synced 2024-12-14 19:49:15 +08:00
202 lines
8.2 KiB
Python
202 lines
8.2 KiB
Python
"""Spawn a command with pipes to its stdin, stdout, and optionally stderr.
|
|
|
|
The normal os.popen(cmd, mode) call spawns a shell command and provides a
|
|
file interface to just the input or output of the process depending on
|
|
whether mode is 'r' or 'w'. This module provides the functions popen2(cmd)
|
|
and popen3(cmd) which return two or three pipes to the spawned command.
|
|
"""
|
|
|
|
import os
|
|
import sys
|
|
import warnings
|
|
warnings.warn("The popen2 module is deprecated. Use the subprocess module.",
|
|
DeprecationWarning, stacklevel=2)
|
|
|
|
__all__ = ["popen2", "popen3", "popen4"]
|
|
|
|
try:
|
|
MAXFD = os.sysconf('SC_OPEN_MAX')
|
|
except (AttributeError, ValueError):
|
|
MAXFD = 256
|
|
|
|
_active = []
|
|
|
|
def _cleanup():
|
|
for inst in _active[:]:
|
|
if inst.poll(_deadstate=sys.maxint) >= 0:
|
|
try:
|
|
_active.remove(inst)
|
|
except ValueError:
|
|
# This can happen if two threads create a new Popen instance.
|
|
# It's harmless that it was already removed, so ignore.
|
|
pass
|
|
|
|
class Popen3:
|
|
"""Class representing a child process. Normally, instances are created
|
|
internally by the functions popen2() and popen3()."""
|
|
|
|
sts = -1 # Child not completed yet
|
|
|
|
def __init__(self, cmd, capturestderr=False, bufsize=-1):
|
|
"""The parameter 'cmd' is the shell command to execute in a
|
|
sub-process. On UNIX, 'cmd' may be a sequence, in which case arguments
|
|
will be passed directly to the program without shell intervention (as
|
|
with os.spawnv()). If 'cmd' is a string it will be passed to the shell
|
|
(as with os.system()). The 'capturestderr' flag, if true, specifies
|
|
that the object should capture standard error output of the child
|
|
process. The default is false. If the 'bufsize' parameter is
|
|
specified, it specifies the size of the I/O buffers to/from the child
|
|
process."""
|
|
_cleanup()
|
|
self.cmd = cmd
|
|
p2cread, p2cwrite = os.pipe()
|
|
c2pread, c2pwrite = os.pipe()
|
|
if capturestderr:
|
|
errout, errin = os.pipe()
|
|
self.pid = os.fork()
|
|
if self.pid == 0:
|
|
# Child
|
|
os.dup2(p2cread, 0)
|
|
os.dup2(c2pwrite, 1)
|
|
if capturestderr:
|
|
os.dup2(errin, 2)
|
|
self._run_child(cmd)
|
|
os.close(p2cread)
|
|
self.tochild = os.fdopen(p2cwrite, 'w', bufsize)
|
|
os.close(c2pwrite)
|
|
self.fromchild = os.fdopen(c2pread, 'r', bufsize)
|
|
if capturestderr:
|
|
os.close(errin)
|
|
self.childerr = os.fdopen(errout, 'r', bufsize)
|
|
else:
|
|
self.childerr = None
|
|
|
|
def __del__(self):
|
|
# In case the child hasn't been waited on, check if it's done.
|
|
self.poll(_deadstate=sys.maxint)
|
|
if self.sts < 0:
|
|
if _active is not None:
|
|
# Child is still running, keep us alive until we can wait on it.
|
|
_active.append(self)
|
|
|
|
def _run_child(self, cmd):
|
|
if isinstance(cmd, basestring):
|
|
cmd = ['/bin/sh', '-c', cmd]
|
|
os.closerange(3, MAXFD)
|
|
try:
|
|
os.execvp(cmd[0], cmd)
|
|
finally:
|
|
os._exit(1)
|
|
|
|
def poll(self, _deadstate=None):
|
|
"""Return the exit status of the child process if it has finished,
|
|
or -1 if it hasn't finished yet."""
|
|
if self.sts < 0:
|
|
try:
|
|
pid, sts = os.waitpid(self.pid, os.WNOHANG)
|
|
# pid will be 0 if self.pid hasn't terminated
|
|
if pid == self.pid:
|
|
self.sts = sts
|
|
except os.error:
|
|
if _deadstate is not None:
|
|
self.sts = _deadstate
|
|
return self.sts
|
|
|
|
def wait(self):
|
|
"""Wait for and return the exit status of the child process."""
|
|
if self.sts < 0:
|
|
pid, sts = os.waitpid(self.pid, 0)
|
|
# This used to be a test, but it is believed to be
|
|
# always true, so I changed it to an assertion - mvl
|
|
assert pid == self.pid
|
|
self.sts = sts
|
|
return self.sts
|
|
|
|
|
|
class Popen4(Popen3):
|
|
childerr = None
|
|
|
|
def __init__(self, cmd, bufsize=-1):
|
|
_cleanup()
|
|
self.cmd = cmd
|
|
p2cread, p2cwrite = os.pipe()
|
|
c2pread, c2pwrite = os.pipe()
|
|
self.pid = os.fork()
|
|
if self.pid == 0:
|
|
# Child
|
|
os.dup2(p2cread, 0)
|
|
os.dup2(c2pwrite, 1)
|
|
os.dup2(c2pwrite, 2)
|
|
self._run_child(cmd)
|
|
os.close(p2cread)
|
|
self.tochild = os.fdopen(p2cwrite, 'w', bufsize)
|
|
os.close(c2pwrite)
|
|
self.fromchild = os.fdopen(c2pread, 'r', bufsize)
|
|
|
|
|
|
if sys.platform[:3] == "win" or sys.platform == "os2emx":
|
|
# Some things don't make sense on non-Unix platforms.
|
|
del Popen3, Popen4
|
|
|
|
def popen2(cmd, bufsize=-1, mode='t'):
|
|
"""Execute the shell command 'cmd' in a sub-process. On UNIX, 'cmd' may
|
|
be a sequence, in which case arguments will be passed directly to the
|
|
program without shell intervention (as with os.spawnv()). If 'cmd' is a
|
|
string it will be passed to the shell (as with os.system()). If
|
|
'bufsize' is specified, it sets the buffer size for the I/O pipes. The
|
|
file objects (child_stdout, child_stdin) are returned."""
|
|
w, r = os.popen2(cmd, mode, bufsize)
|
|
return r, w
|
|
|
|
def popen3(cmd, bufsize=-1, mode='t'):
|
|
"""Execute the shell command 'cmd' in a sub-process. On UNIX, 'cmd' may
|
|
be a sequence, in which case arguments will be passed directly to the
|
|
program without shell intervention (as with os.spawnv()). If 'cmd' is a
|
|
string it will be passed to the shell (as with os.system()). If
|
|
'bufsize' is specified, it sets the buffer size for the I/O pipes. The
|
|
file objects (child_stdout, child_stdin, child_stderr) are returned."""
|
|
w, r, e = os.popen3(cmd, mode, bufsize)
|
|
return r, w, e
|
|
|
|
def popen4(cmd, bufsize=-1, mode='t'):
|
|
"""Execute the shell command 'cmd' in a sub-process. On UNIX, 'cmd' may
|
|
be a sequence, in which case arguments will be passed directly to the
|
|
program without shell intervention (as with os.spawnv()). If 'cmd' is a
|
|
string it will be passed to the shell (as with os.system()). If
|
|
'bufsize' is specified, it sets the buffer size for the I/O pipes. The
|
|
file objects (child_stdout_stderr, child_stdin) are returned."""
|
|
w, r = os.popen4(cmd, mode, bufsize)
|
|
return r, w
|
|
else:
|
|
def popen2(cmd, bufsize=-1, mode='t'):
|
|
"""Execute the shell command 'cmd' in a sub-process. On UNIX, 'cmd' may
|
|
be a sequence, in which case arguments will be passed directly to the
|
|
program without shell intervention (as with os.spawnv()). If 'cmd' is a
|
|
string it will be passed to the shell (as with os.system()). If
|
|
'bufsize' is specified, it sets the buffer size for the I/O pipes. The
|
|
file objects (child_stdout, child_stdin) are returned."""
|
|
inst = Popen3(cmd, False, bufsize)
|
|
return inst.fromchild, inst.tochild
|
|
|
|
def popen3(cmd, bufsize=-1, mode='t'):
|
|
"""Execute the shell command 'cmd' in a sub-process. On UNIX, 'cmd' may
|
|
be a sequence, in which case arguments will be passed directly to the
|
|
program without shell intervention (as with os.spawnv()). If 'cmd' is a
|
|
string it will be passed to the shell (as with os.system()). If
|
|
'bufsize' is specified, it sets the buffer size for the I/O pipes. The
|
|
file objects (child_stdout, child_stdin, child_stderr) are returned."""
|
|
inst = Popen3(cmd, True, bufsize)
|
|
return inst.fromchild, inst.tochild, inst.childerr
|
|
|
|
def popen4(cmd, bufsize=-1, mode='t'):
|
|
"""Execute the shell command 'cmd' in a sub-process. On UNIX, 'cmd' may
|
|
be a sequence, in which case arguments will be passed directly to the
|
|
program without shell intervention (as with os.spawnv()). If 'cmd' is a
|
|
string it will be passed to the shell (as with os.system()). If
|
|
'bufsize' is specified, it sets the buffer size for the I/O pipes. The
|
|
file objects (child_stdout_stderr, child_stdin) are returned."""
|
|
inst = Popen4(cmd, bufsize)
|
|
return inst.fromchild, inst.tochild
|
|
|
|
__all__.extend(["Popen3", "Popen4"])
|