When creating daemons on Unix-like systems, it's typical to close or redirect stdin, stdout, and stderr. This simple recipe demonstrates that it's not quite as obvious as it might first appear.
Python, 9 lines
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Copy to clipboard1 2 3 4 5 6 7 8 9 | # here's the obvious part!
sys.stdin.close()
sys.stdout.close()
sys.stderr.close()
# this is pretty obscure!
os.close(0)
os.close(1)
os.close(2)
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When would you want to use this? If you have a daemon process and really want to close or redirect the standard file descriptors, you must close or redirect at both the Python and C levels. Consider starting a daemon while ssh'd into a server:
% (mydaemon.py When would you want to use this? If you have a daemon process and really
want to close or redirect the standard file descriptors, you must close or redirect at both the Python and C levels. Consider starting a daemon while ssh'd into a server:
% (mydaemon.py
Tags: sysadmin
? Uh, where's the rest of the explanation?