Issue #5870: Add subprocess.DEVNULL constant.
diff --git a/Lib/subprocess.py b/Lib/subprocess.py
index cc08945..0e15f10 100644
--- a/Lib/subprocess.py
+++ b/Lib/subprocess.py
@@ -431,7 +431,7 @@
return fds
__all__ = ["Popen", "PIPE", "STDOUT", "call", "check_call", "getstatusoutput",
- "getoutput", "check_output", "CalledProcessError"]
+ "getoutput", "check_output", "CalledProcessError", "DEVNULL"]
if mswindows:
from _subprocess import CREATE_NEW_CONSOLE, CREATE_NEW_PROCESS_GROUP
@@ -456,6 +456,7 @@
PIPE = -1
STDOUT = -2
+DEVNULL = -3
def _eintr_retry_call(func, *args):
@@ -800,6 +801,10 @@
# Child is still running, keep us alive until we can wait on it.
_active.append(self)
+ def _get_devnull(self):
+ if not hasattr(self, '_devnull'):
+ self._devnull = os.open(os.devnull, os.O_RDWR)
+ return self._devnull
def communicate(self, input=None, timeout=None):
"""Interact with process: Send data to stdin. Read data from
@@ -889,6 +894,8 @@
p2cread, _ = _subprocess.CreatePipe(None, 0)
elif stdin == PIPE:
p2cread, p2cwrite = _subprocess.CreatePipe(None, 0)
+ elif stdin == DEVNULL:
+ p2cread = msvcrt.get_osfhandle(self._get_devnull())
elif isinstance(stdin, int):
p2cread = msvcrt.get_osfhandle(stdin)
else:
@@ -902,6 +909,8 @@
_, c2pwrite = _subprocess.CreatePipe(None, 0)
elif stdout == PIPE:
c2pread, c2pwrite = _subprocess.CreatePipe(None, 0)
+ elif stdout == DEVNULL:
+ c2pwrite = msvcrt.get_osfhandle(self._get_devnull())
elif isinstance(stdout, int):
c2pwrite = msvcrt.get_osfhandle(stdout)
else:
@@ -917,6 +926,8 @@
errread, errwrite = _subprocess.CreatePipe(None, 0)
elif stderr == STDOUT:
errwrite = c2pwrite
+ elif stderr == DEVNULL:
+ errwrite = msvcrt.get_osfhandle(self._get_devnull())
elif isinstance(stderr, int):
errwrite = msvcrt.get_osfhandle(stderr)
else:
@@ -1026,6 +1037,8 @@
c2pwrite.Close()
if errwrite != -1:
errwrite.Close()
+ if hasattr(self, '_devnull'):
+ os.close(self._devnull)
# Retain the process handle, but close the thread handle
self._child_created = True
@@ -1159,6 +1172,8 @@
pass
elif stdin == PIPE:
p2cread, p2cwrite = _create_pipe()
+ elif stdin == DEVNULL:
+ p2cread = self._get_devnull()
elif isinstance(stdin, int):
p2cread = stdin
else:
@@ -1169,6 +1184,8 @@
pass
elif stdout == PIPE:
c2pread, c2pwrite = _create_pipe()
+ elif stdout == DEVNULL:
+ c2pwrite = self._get_devnull()
elif isinstance(stdout, int):
c2pwrite = stdout
else:
@@ -1181,6 +1198,8 @@
errread, errwrite = _create_pipe()
elif stderr == STDOUT:
errwrite = c2pwrite
+ elif stderr == DEVNULL:
+ errwrite = self._get_devnull()
elif isinstance(stderr, int):
errwrite = stderr
else:
@@ -1374,6 +1393,8 @@
os.close(c2pwrite)
if errwrite != -1 and errread != -1:
os.close(errwrite)
+ if hasattr(self, '_devnull'):
+ os.close(self._devnull)
# Wait for exec to fail or succeed; possibly raising an
# exception (limited in size)