linux - huponexit off and ampersand inputted - but program still close -

[oracle@centos1 ~]$ shopt | grep hupon huponexit       off  [oracle@centos1 ~] sqldeveloper & -- program being ran 

with above, stated there no hup signal sent on exit. when close shell, program still gets closed.

why ?

it's because sqldeveloper attached terminal. nohup works because detaches command automatically — see excerpt nohup(1):

if standard input terminal, redirect /dev/null. if standard output terminal, append output 'nohup.out' if possible, '$home/nohup.out' otherwise. if standard error terminal, redirect standard output. save output file, use 'nohup command > file'.

it should work without nohup if hand — try example:

sqldeveloper < /dev/null &> /dev/null &