How do I get nohup.out flushed more often?

Question

On Ubuntu 10.04, I have a long Python program that prints a bunch of output; I run this under "nohup". However, it waits until the end to put all the text in nohup.out. When I run similar programs under FreeBSD, each line gets sent to nohup.out. Is there a Ubuntu setting I can set to get the output faster?

score 9 · Accepted Answer · answered Sep 13 '10 at 03:49

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Yeh, this is got to do with the way stdout is buffered by default on Linux. You need to explicitly run setbuf() in the code to override this behavior.

My suggestion is to avoid nohup, if you're using the bash shell, it allows you to disassociate the command from your shell

$ ( my_cmd > ~/output.log 2>&1 & )

You can also use disown for a similar effect on a currently running job.

answered Sep 13 '10 at 03:49

Philip Reynolds

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Why would you recommend avoiding nohup? – Warner Sep 13 '10 at 14:36
I think because putting setbuf() in every Python script that might be nohup'd is silly. – Paul Hoffman Sep 15 '10 at 17:22
This works, though I'm still getting buffering. That could be because of the program (server) i'm running though-- have to look into buffering it may be doing. – Chris Prince Jun 03 '17 at 23:32

score 5 · Answer 2 · edited May 23 '17 at 11:33

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Since your program is python, you can run it with python -u. Alternatively you might find the unbuffer program useful.

edited May 23 '17 at 11:33

Community

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answered Jul 31 '13 at 22:47

Zac Thompson

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How do I get nohup.out flushed more often?

2 Answers2