an", type "an" then hit Tab key would complete it to "anaconda". Then, if you additionally type "-" and hit Tab key, completed to anaconda-webui.log.." instead of "-", completed to anaconda.log.Filename completion is a feature of the shell, not the filesystem. If the shell supports it, it won't matter what filesystem, UFS. ZFS, ext2/3/4, FAT, etc.On ZFS (and if I recall correctly, {t}csh and some others excluding /bin/sh), incremental completions would work.
Define "substring completion". If you mean "filename completion" then I believe /bin/sh already does that. At least on my system with stock init files filename completion works with at least the ls command.Do you see a chance of substring completion getting implemented in /bin/sh ?
I would have to open an enhancement request?