readonly var=value prevent shell scripter changing value of variable var, there is no restriction for the shell itself.
Try: set -o posix readonly | grep SHELLOPTS and: set +o posix readonly | grep SHELLOPTS to see the missing of `posix` in 2nd command, the readonly variable SHELLOPTS was changed by the shell. On Fri, Jan 1, 2016 at 7:04 AM, nerdopolis <bluescreen_aven...@verizon.net> wrote: > I tested on > 4.2.45(1)-release > > basically I have tested > nerdopolis@nerdopolis:~$ readonly POSIXLY_CORRECT=1 > nerdopolis@nerdopolis:~$ set +o posix > nerdopolis@nerdopolis:~$ echo $POSIXLY_CORRECT > > nerdopolis@nerdopolis:~$ > > Although I will admit I'm not sure if it's supposed to do that or not > >
