[issue23750] Clarify difference between os.system/subprocess.call in section Replacing os.system()
Martin Panter added the comment: Here is a patch: * Use different return value variable names and point out that they are encoded differently * Add another bullet point about signal handling * Fix os.system() documentation of the return value. My understanding is it is the C standard that does not define the return value, and Posix essentially means Unix. -- keywords: +patch stage: - patch review versions: +Python 2.7, Python 3.4, Python 3.5, Python 3.6 Added file: http://bugs.python.org/file39767/system-subprocess.patch ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue23750 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue23750] Clarify difference between os.system/subprocess.call in section Replacing os.system()
New submission from Andreas Sommer: Reading over the section Replacing os.system() (https://docs.python.org/2/library/subprocess.html#replacing-os-system), one might assume that the return value of os.system and subprocess.call are equivalent. status = os.system(mycmd + myarg) # becomes status = subprocess.call(mycmd + myarg, shell=True) However, they are not. Example: import sys import os import subprocess print subprocess.call(false) print os.system(false) gives 1 and 256, respectively. Maybe this could be rephrased for clarity, or a hint added. -- assignee: docs@python components: Documentation messages: 239028 nosy: Andreas Sommer, docs@python priority: normal severity: normal status: open title: Clarify difference between os.system/subprocess.call in section Replacing os.system() type: enhancement ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue23750 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue23750] Clarify difference between os.system/subprocess.call in section Replacing os.system()
Martin Panter added the comment: Another difference is that (at least POSIX) system() blocks SIGINT and SIGQUIT while the child is running. Compare: $ python3 -c 'print(Waiting); import os; print(Returned, os.system(sleep 3 exit 3))' Sleeping Returned 768 $ python3 -c 'print(Sleeping); import os; print(Returned, os.system(sleep 3 exit 3))' Waiting ^CReturned 2 # Hit Ctrl+C during sleep command $ python3 -c 'print(Sleeping); import subprocess; print(Returned, subprocess.call(sleep 3 exit 3, shell=True))' Sleeping Returned 3 $ python3 -c 'print(Sleeping); import subprocess; print(Returned, subprocess.call(sleep 3 exit 3, shell=True))' Sleeping ^CTraceback (most recent call last): File string, line 1, in module File /usr/lib/python3.4/subprocess.py, line 539, in call return p.wait(timeout=timeout) File /usr/lib/python3.4/subprocess.py, line 1566, in wait (pid, sts) = self._try_wait(0) File /usr/lib/python3.4/subprocess.py, line 1514, in _try_wait (pid, sts) = _eintr_retry_call(os.waitpid, self.pid, wait_flags) File /usr/lib/python3.4/subprocess.py, line 491, in _eintr_retry_call return func(*args) KeyboardInterrupt [Exit 1] -- nosy: +vadmium ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue23750 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
