Bash – Autocomplete Filenames Using Compgen

(No answer to your exact question, but many workarounds.)

You don't need to match your scripting shell with your interactive shell. (For example, most (t)csh or zsh users write sh scripts). If you have or can install a better interactive shell than the Bourne shell (zsh, bash, tcsh), go for it. Even if you can't, look if there's a ksh, which is likely to have slightly better interactive features than a Bourne shell.

You can check what character the tab key sends by entering echo ' Ctrl+V Tab ' | od -t x1 Enter. 0000000 09 0a (i.e. at position 0, two characters, a tab and a newline) is the expected output. I don't expect this to be the issue.

If you can't get a comfortable environment, you could try doing more things remotely, using your local machine for interaction as much as possible. This has its ups and downs.

• From Linux (or most other unices including OSX, but not from Windows), you can use sshfs to access the remote filesystem.
• Within Emacs, you can easily browse remote files via Tramp (open /os390hostname:/path/on/remote/machine, you get completion). You can also use Eshell to get a remote shell interface (an Emacs built-in shell); if you change to a remote directory (cd /os390hostname:/path/on/remote/machine), the external commands you launch will be executed on the remote machine. If you need to run commands as root, Tramp (and Eshell which is based on it) can combine ssh with su or sudo.

Believe it might be better to use compgen instead of find in this case.

You probably already have a completion script with system. Try e.g.

locate bash_completion

On Debian variants this is probably:

/usr/share/bash-completion/bash_completion

where you find e.g. _filedir. So the simplest way then would be something in the direction of:

*)
    pushd "/some/path" >/dev/null
    _filedir
    popd >/dev/null

If that is not an option this could be a starter:

_comp_by_path()
{
    local opt cur dir
    local IFS=$'\n' x tmp
    local -a tokens

    opt="$1"
    cur="$2"
    dir="$3"

    # Enter target directory
    pushd "$dir" >/dev/null

    # Get directories, filtered against current
    [[ "$opt" != "-f" ]] && \
    x=$( compgen -d -- "$cur" ) &&
    while read -r tmp; do
        tokens+=( "$tmp" )
    done <<< "$x"

    # Get files, filtered against current
    [[ "$opt" != "-d" ]] && \
    x=$( compgen -f -- "$cur" ) &&
    while read -r tmp; do
        tokens+=( "$tmp" )
    done <<< "$x"

    # If anything found
    if [[ ${#tokens[@]} -ne 0 ]]; then
        # Make sure escaping is OK
        compopt -o filenames 2>/dev/null
        COMPREPLY+=( "${tokens[@]}" )
    fi

    # Go back
    popd >/dev/null
}

_GetOptMyCommand()
{
    local cur

    COMPREPLY=()
    cur="${COMP_WORDS[COMP_CWORD]}"

    case "$cur" in
    -*)
        COMPREPLY=( $( compgen -W "-h -l --help --list --" -- "$cur" ) );;
    *)
        _comp_by_path "any" "$cur" "/some/path"
    esac
}

complete -F _GetOptMyCommand my_command

A variant using find could be something in direction of this:

_zaso()
{
    local dir="$1"

    pushd "$dir" >/dev/null
    find * -maxdepth 0 2>/dev/null
    popd >/dev/null
}

_comp_with_find()
{
    local cur dir      
    local IFS=$'\n'

    cur="$1"
    dir="$2"

    compopt -o filenames 2>/dev/null
    COMPREPLY=( $( compgen -W "$(_zaso "$dir")" -- "$cur" ) );
}

Also note that printf in Bash has a %q option. So to generate quoted strings this is an option to play with:

find * -maxdepth 0 2>/dev/null && \
while read -r tmp; do
    printf "%q\n" "$tmp"
done <<< "$x"

Also not that file names can have newline characters in which a lot of this will break. Have not found a way to use \0 with compgen.