On Wed, Mar 27, 2019 at 02:06:51PM +0100, joerg...@snafu.de wrote: > If I declare a global read-only variable and I try to declare a local > variable with that name, I can not create > the local variable. > I expect that local variables can be declared independently for the > global variables.
The purpose of the readonly flag on shell variables is to support the restricted shell. I will pause while you laugh and/or cry. In order for a restricted shell to have half a chance of working (keeping the user imprisoned), the PATH variable has to be immutable. If the user can modify PATH, they can run a real shell and escape. So, in rbash and friends, PATH gets marked readonly, and bash treats the readonly flag as sacrosanct. Allowing a user to work around it simply by creating a function would let them break out of the restricted shell too easily. Readonly is forever.
