Autocomplete of filename in directory

Try:

_codeComplete()
{
    local cur=${COMP_WORDS[COMP_CWORD]}
    COMPREPLY=( $(compgen -W "$(ls /something/)" -- $cur) )
}

complete -F _codeComplete hi

You need to specify the -W option in compgen and also quote the command which produces the wordlist.

More information on how to write completion functions on this blog: Writing your own Bash Completion Function