CDPATH aware completion plugin for bash

Its very annoying how cd command of bash does not integrate nicely with the CDPATH variable it defines in the context of suggested completions whe the user enters TAB.

The following script addresses the issue to a large extent (naturally, with some bugs).

Just paste the following into your .bashrc and load the .bashrc as usual, either by doing ". .bashrc" in your current shell or by logging in afresh.

complete -o nospace -F expand_to_dir_list cd

expand_to_dir_list()
{
    pattern=$2

    if [ "`echo $pattern | grep '^\\$'`" != "" ]
    then
        COMPREPLY=()

        #If there is a slash at the end ...
        if [ "`echo $pattern | grep '/$'`" != "" ]
        then
            COMPREPLY[0]=`eval "echo $pattern"`
            return
        fi

        #List env variables which begin with the specified prefix
        pattern=`echo $pattern | tr -d '$'`
        for setting in `env`
        do
            vn=`echo $setting | cut -d'=' -f1`
            if [ "`echo $vn | grep "^$pattern"`" != "" ]
            then
                COMPREPLY[$index]=\$$vn/
                index=`expr $index + 1`
            fi
        done

        return
    #pattern=`echo eval $pattern`
    fi


    slash_in_pattern=`echo $pattern | grep /`

    if [ "$slash_in_pattern" != "" ]
    then
        path_prefix=`echo $pattern|sed -e 's/\\/[^\\/]*\$//'`
        name_prefix=`echo $pattern|sed -e 's/^.*\\/\\([^\\/]*\\)\$/\\1/'`
    else
        path_prefix="."
        name_prefix=$pattern
    fi

    p_dirs=()
    n_p_dirs=0
    if [ "`echo $path_prefix|grep "^/"`" != "" ] 
    then
        p_dirs[0]=$path_prefix
        n_p_dirs=1
    else
        #Add . to the head of list
        cdpath=".:"$CDPATH
        for p_dir in `echo $cdpath | tr ':' '\n' | sort -u`
        do
            if [ -d "$p_dir/$path_prefix" ]
            then
                p_dirs[$n_p_dirs]=$p_dir/$path_prefix
                n_p_dirs=`expr $n_p_dirs + 1`
            fi
        done
    fi
    
    COMPREPLY=()

    index=0
    for p_dir in "${p_dirs[@]}"
    do
        for entry in `ls $p_dir`
        do
            prefixness=`echo $entry | grep "^$name_prefix.*"`
            if [ -d "$p_dir"'/'"$entry" ]  && [ "$prefixness" != "" ]
            then
                COMPREPLY[$index]=$entry/
                if [ "$p_dir" != "." ]
                then
                    COMPREPLY[$index]=$p_dir/${COMPREPLY[$index]}
                fi
                #Clean path
                COMPREPLY[$index]=`echo ${COMPREPLY[$index]}|sed -e 's/\\/\\//\\//g' | sed -e 's/\\/\\.\\//\\//g'`

                #remove a prefixing pwd , if any
                pwd=`pwd|sed -e 's/\\//\\\\\\//g'`
                pwd=$pwd\\/
                COMPREPLY[$index]=`echo ${COMPREPLY[$index]}|sed -e "s/^$pwd//"`

                index=`expr $index + 1`
            fi
        done
    done
}