diff options
| -rw-r--r-- | Doc/library/subprocess.rst | 10 | ||||
| -rw-r--r-- | Lib/test/test_cmd_line.py | 6 |
2 files changed, 14 insertions, 2 deletions
diff --git a/Doc/library/subprocess.rst b/Doc/library/subprocess.rst index 7952f68..9853e62 100644 --- a/Doc/library/subprocess.rst +++ b/Doc/library/subprocess.rst @@ -152,6 +152,12 @@ This module also defines four shortcut functions: retcode = call(["ls", "-l"]) + .. warning:: + + Like :meth:`Popen.wait`, this will deadlock if the child process + generates enough output to a stdout or stderr pipe such that it blocks + waiting for the OS pipe buffer to accept more data. + .. function:: check_call(*popenargs, **kwargs) @@ -164,6 +170,10 @@ This module also defines four shortcut functions: check_call(["ls", "-l"]) + .. warning:: + + See the warning for :func:`call`. + .. function:: check_output(*popenargs, **kwargs) diff --git a/Lib/test/test_cmd_line.py b/Lib/test/test_cmd_line.py index 84588cf..72edc2e 100644 --- a/Lib/test/test_cmd_line.py +++ b/Lib/test/test_cmd_line.py @@ -2,6 +2,7 @@ # All tests are executed with environment variables ignored # See test_cmd_line_script.py for testing of script execution +import os import test.support, unittest import os import sys @@ -40,8 +41,9 @@ class CmdLineTest(unittest.TestCase): def exit_code(self, *args): cmd_line = [sys.executable, '-E'] cmd_line.extend(args) - return subprocess.call(cmd_line, stdout=subprocess.PIPE, - stderr=subprocess.PIPE) + with open(os.devnull, 'w') as devnull: + return subprocess.call(cmd_line, stdout=devnull, + stderr=subprocess.STDOUT) def test_directories(self): self.assertNotEqual(self.exit_code('.'), 0) |