complete-e

#!/bin/bash

save=$(bind -p; bind -X)
function clean-up {
    bind -r '\C-i'
    bind -f /dev/stdin <<< "$save"
}
trap 'clean-up' RETURN

function write-options {
    typeset o
    for o do
        printf '* %s\n' "$o"
    done
    printf '%s\n' --
} >&2

function complete-e {
    typeset o nicks=$1
    typeset -a opts=()
    typeset -a matches=()

    mapfile -t opts < "$nicks"

    for o in "${opts[@]}"; do
        [[ $o = "$READLINE_LINE"* ]] && matches+=("$o")
    done

    if (( ${#matches[@]} == 1 )); then
        READLINE_LINE="$matches "
        READLINE_POINT=$(( ${#matches} + 1 ))
    else
        write-options "${matches[@]}"
    fi

}

bind -x '"\C-i":complete-e /dev/fd/3'
read -e -p 'nick> ' nick 3<<NICKS
llua
lhunath
geirha
duck
dualbus
ormaaj
NICKS

echo "nick was: $nick"