policycoreutils: fixfiles: refactor into the `set -u` dialect
This commit allows the use of `set -u` to detect reads of unset variables.
But what I really liked was making the code more explicit about these
modes. I hope that this is easier for a new reader to reason about.
`fixfiles restore` has accumulated five different modes it can run in.
Now use a single variable to indicate the mode, out-of-band of the
variables used for the individual modes.
Apparently `set -u` / `set -o nounset` doesn't work correctly with arrays.
If we ever need bash arrays, we can simply remove `set -u`. The `set -u`
dialect is a strict subset. See http://mywiki.wooledge.org/BashFAQ/112
Extra notes:
RESTORE_MODE was created because I couldn't bring myself to use an empty
FILEPATH, as a special case to indicate the default mode. Arguments
to the script (paths) could be empty already, so it would mean I had to
work out how we behaved in that case and decide whether it was reasonable.
It turns out the `-B | -N time` mode is distinct and does not respect
paths. So we can tell the user we're not going to do anything with the
paths they passed. Make sure this distinction is shown in the usage error
message.
We already rejected the combination of `-R rpmpackage,... dir/file...`.
Being aware of the different modes just causes more bogus combinations
to be rejected.
Signed-off-by: Alan Jenkins <alan.christopher.jenkins@gmail.com>
2 files changed