Whats the purpose of the nohup command?

[srinivasm]

Hi,

In one of the shell script, nohup command used to connect to the SQLPLUS from the Operating System as follows

nohup sqlplus -s /nolog @staging1.sql ${WORK_SCHEMA} ${WORK_PWD} ${WORK_SID} ${DATE_MARK}

Whats the purpose of the "nohup" command ?

Operating Sysytem : Solaris
Databse : Oracle 9i

Thank you in advance

Srinivas Medukonduru

[Sameer]

http://www.unidata.ucar.edu/cgi-bin/man-cgi?nohup+1

[rotem_fo]

The nohup utility invokes a command with the arguments supplied. When the command is invoked, nohup arranges for the SIGHUP signal to be ignored by the process.
Hi,
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 children 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 programmatically has chosen to ignore SIGHUP.

/usr/bin/nohup
Processes run by /usr/bin/nohup are immune to SIGHUP (hangup) and SIGQUIT (quit) signals.

/usr/xpg4/bin/nohup
Processes run by /usr/xpg4/bin/nohup are immune to SIGHUP.
The nohup utility does not arrange to make processes immune to a SIGTERM (terminate) signal, so unless they arrange to be immune to SIGTERM or the shell makes them immune to SIGTERM, they will receive it.

Cheers.