Bash for Camel.CaseNames (cd CCN <tab> => cd Camel.CaseName)

Question

I am looking for a way to implement completion for file / directory names of the form

Foo.Bar.Baz/
Foo.Bar.QuickBrown.Fox/
Foo.Bar.QuickBrown.Interface/
Foo.Bar.Query.Impl/

where completion will work like

~ $ cd QI<tab><tab>
Foo.Bar.QuickBrown.Interface/    Foo.Bar.Query.Impl/
~ $ cd QIm<tab><enter>
~/Foo.Bar.Query.Impl $

However, my simplified approach to creating a glob template from input (e.g. QIm→ *Q*I*m) does not exactly work for files / directories using the same prefix. In the above case, I get

~ $ cd QI<tab><tab>
Foo.Bar.QuickBrown.Interface/    Foo.Bar.Query.Impl/
~ $ cd Foo.Bar.Qu<tab><tab>
Foo.Bar.QuickBrown.Fox/  Foo.Bar.QuickBrown.Interface/  Foo.Bar.Query.Impl/

i.e. bash replaces the current word with the longest common prefix for possible terminations, which in this case leads to a larger set of terminations.

Here is my completion function:

_camel_case_complete()
{
    local cur pat
    COMPREPLY=()
    cur="${COMP_WORDS[COMP_CWORD]}"
    pat=$(sed -e 's/\([A-Z]\)/*\1*/g' -e 's/\*\+/*/g' <<< "$cur")
    COMPREPLY=( $(compgen -G "${pat}" -- $cur ) )
    return 0
}

Any tips on how to fix this without breaking the normal filling of the file / directory name?

Answer 1

. :

% ls -l
total 20
-rw-r--r-- 1 root root  315 2016-06-02 18:30 compspec
drwxr-xr-x 2 root root 4096 2016-06-02 17:56 Foo.Bar.Baz
drwxr-xr-x 2 root root 4096 2016-06-02 17:56 Foo.Bar.Query.Impl
drwxr-xr-x 2 root root 4096 2016-06-02 17:56 Foo.Bar.QuickBrown.Fox
drwxr-xr-x 2 root root 4096 2016-06-02 17:56 Foo.Bar.QuickBrown.Interface
% cat compspec
_camel_case_complete()
{
    local cur=$2
    local pat

    pat=$(sed -e 's/[A-Z]/*&/g' -e 's/$/*/' -e 's/\*\+/*/g' <<< "$cur")
    COMPREPLY=( $(compgen -G "${pat}" ) )
    if [[ ${#COMPREPLY[@]} -gt 1 ]]; then
        # Or use " " instead of "__"
        COMPREPLY[${#COMPREPLY[@]}]="__"
    fi

    return 0
}

complete -F _camel_case_complete cd
% . ./compspec
% cd QI<TAB><TAB>
__                            Foo.Bar.QuickBrown.Interface
Foo.Bar.Query.Impl
% cd QIm<TAB>
% cd Foo.Bar.Query.Impl<SPACE>