/usr/lib/python2.7/popen2.py is in python2.7-minimal 2.7.3-0ubuntu3.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 | """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"])
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