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When we need nohup


 
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# 1  
Old 10-07-2009
When we need nohup

Hi,

I've read the man page on nohup.
But I still can't see what's the differences if
we just send a process to background versus
sending a nohup process to background.

eg:

myprocess &
vs
nohup myprocess &

Without nohup, myprocess would still run uninterruptible
at background right?

Please comment.


Thanks in advance.
# 2  
Old 10-07-2009
When the parent shell exits your background jobs (started without nohup) will exit too.

Quote:
DESCRIPTION
The nohup utility invokes the named command with the argu-
ments supplied. When the command is invoked, nohup arranges
for the SIGHUP signal to be ignored by the process.

The nohup utility can be used when it is known that command
will take a long time to run and the user wants to logout of
the terminal; when a shell exits, the system sends its chil-
dren SIGHUP signals, which by default cause them to be
killed. All stopped, running, and background jobs will
ignore SIGHUP and continue running, if their invocation is
preceded by the nohup command or if the process programmati-
cally has chosen to ignore SIGHUP.
# 3  
Old 10-07-2009
If you don't use nohup , whatever output is being generated by the script you executed will be thrown to your terminal that will disturb your work when you do something in the prompt. So, It is better to use nohup when running multiple jobs in background

Also, you can log the output in nohup.out when we use nohup command.
 

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