Describe the bug

redis-cli exit code can be 1 or 255 on failure. Looks like it's inconsistent, not sure when to expect one or another.

To reproduce

This is how 255 is returned:

noninteractive() returns REDIS_ERR on failure, which is -1, it becomes 255 as exit codes are in range 0-255.

Expected behavior

As far as I see, nothing is wrong by doing this but it'd nice to be consistent. If we want to have a quick fix and use exit code 1 on all cases, we might be introducing a breaking change? I'm not sure if anybody relies on this.

Also, we had a quick conversation with @yossigo, we may further improve error codes by using different exit codes for different error cases as well.