Quick directory changing, with autocompletion: howto

David the H. · 09-07-2009, 01:08 PM

I've been fooling around with this for a while, and I've just gotten it to work the way I always wanted it. I've managed to create a set of functions that will let you cd directly into preset directories, and use bash_completion to quickly navigate subdirectories as well. Hopefully others will find this useful as well.

First, create a set of variables and simple functions like this in your bashrc:

Code:

export MUSICDIR="/mount/bigdrive/media/music"
cdmusic ()
{
    cd "$MUSICDIR/$1" || cd "$MUSICDIR"
}

Now you can quickly cd into your music directory with "cdmusic", and further into subdirectories with e.g. "cdmusic rock/pink_floyd". But it won't autocomplete the directory listings for you...yet.

To enable bash_completion for the command, create a new file in /etc/bash_completion.d/ and name it something like 10_cd2dirs. For each function you've defined above, include the following code:

Code:

_cdmusic()
{

        local CD_PATH="$MUSICDIR"
        local IFS=$'\t\n' cur=`_get_cword` i j k

        # Enable -o filenames option, see Debian bug #272660
        compgen -f /non-existing-dir/ >/dev/null

        local -r mark_dirs=$(_rl_enabled mark-directories && echo y)
        local -r mark_symdirs=$(_rl_enabled mark-symlinked-directories && echo y)

        # loop through CD_PATH contents
        for i in ${CD_PATH}; do
                # create an array of matched subdirs
                k="${#COMPREPLY[@]}"
                for j in $( compgen -d $i/$cur ); do
                        if [[ ( $mark_symdirs && -h $j || $mark_dirs && ! -h $j ) && ! -d ${j#$i/} ]]; then
                                j="${j}/"
                        fi
                        COMPREPLY[k++]=${j#$i/}
                done
        done

        if [[ ${#COMPREPLY[@]} -eq 1 ]]; then
            i=${COMPREPLY[0]}
            if [ "$i" == "$cur" ] && [[ $i != "*/" ]]; then
                COMPREPLY[0]="${i}"
            fi
        fi

        return 0
}

if shopt -q cdable_vars; then
    complete -o nospace -v -F _cdmusic $nospace cdmusic
else
    complete -o nospace -F _cdmusic $nospace cdmusic
fi

# Above code is a modified version of the
# bash_completion function for "cd", but this
# only lists entries in the directory defined
# in CD_PATH.  I'm not 100% sure what all the
# commands do, but it seems to work for me.

Just be sure to modify the names on the first and final lines to match each function name, and make CD_PATH the main target directory of that function.

Now just reload your bashrc (or open a new console) and you should be able to cruise your directories in speed and comfort.

kofucii · 09-08-2009, 05:41 AM

Can't you just use CDPATH function in bash? Something like this:

export CDPATH=.:/mount/bigdrive/media/music

David the H. · 09-08-2009, 08:01 AM

Oh sure, just ruin take all of the steam out of my hard work, why don't you?

Actually, I simply wasn't aware that you could do that with CDPATH.

Reading the description of it more carefully, I now realize that. You can even specify multiple paths.

Still, I think I prefer having specific cd commands for different locations, as opposed to one big path completion pool. It's easier for me psychologically.

Oh, well. At least I have my working functions, and I also learned a bit about how bash_completion works.