set_command_cursor

#!/usr/bin/env bash

bind -x '"'"\C-k"'":"set_command_cursor"'

set_command_cursor() 
{
local BACKSPACE=$(printf "0000000 005177\n0000002")
local TAB=$'\x09' 
#local SHIFT_TAB=$(printf "????0000000 005033\n0000002") # todo:
#local SHIFT_TAB="$(echo -e '\e[Z')" #doesn'twork
local SHIFT_TAB="$(echo -e '\e1\Ci')" #doesn'twork
local ESCAPE="$(echo -e '\e')"
local RETURN=$(printf "0000000 000012\n0000001")

#colors
local MATCH='\e[36m'
local CURRENT='\e[30;46m'
local RESET='\e[0m'

local initial_command="$READLINE_LINE"
local new_command_point=$READLINE_POINT

local highlighted="$initial_command"
local search=""
local matches=""
local index=0
local max_index=0

local SHOW_STATUS=1
local status=""

local prompt=$(PS1="$PS1" debian_chroot="$debian_chroot" "$BASH" --norc -i </dev/null 2>&1 | sed -n '${s/^\(.*\)exit$/\1/p}')

tput sc

while true
do
	tput rc ; tput ed

	if [[ $SHOW_STATUS ]] ; then
		[[ "$search" == "" ]] && status="[0]" || { [[ ${#matches[@]} -gt 1 ]] && status="[$(( ${#matches[@]} - 1 ))]" || status="[!]" ; }
		
		status=" $MATCH$status$RESET"
	fi


	highlighted=${highlighted//\\/\\\\}
	printf "$prompt$highlighted$status"

	IFS='' read -r -sn 1 key

	if [[ "$key" =~ [A-Za-z0-9_!@#$%()+-={}:\;?\'|,.\<\>] ]]; then
		search="$search$key"
		_scc_keep_position

	elif [[ $(echo "$key" | od) == "$BACKSPACE" ]]; then
		if [[ "$search" != "" ]] ; then
			search=${search:0:-1} && _scc_keep_position
		else
			matches=("$highlighted")
		fi

	elif [[ "$key" == "$TAB" ]]; then
		[[ $index -lt $max_index ]] && index=$((index + 1)) && _scc

	elif [[ "$key" == "$SHIFT_TAB" ]]; then
		echo SHIFT-TAB working!
		[[ $index -gt 0 ]] && index=$((index - 1)) && _scc

	elif [[ $(echo "$key" | od) == "$RETURN" ]]; then
		tput rc ; tput ed
		READLINE_POINT=${matches[$index]}
		printf "\r" ; return
	
	elif [[ "$key" == "$ESCAPE" ]]; then
		tput rc ; tput ed
		return
	fi
done
}

_scc()
{
[[ -z "$search" ]] && highlighted="$initial_command" && max_index=0 && return

IFS='' read -r -d '' code <<EOF
	\$tag='$$_SCC_tag' ;
	\$search_length = length("$search") ;
	\$search = quotemeta("$search") ;

	print pos() - \$search_length . qq[\n] while(/\$search/g) ; # matches
	/((?:.*?\$search){$index}.*?)(\$search)(.*)/ and \$_="\$1\$tag\$2\$3\\n" ; # tag current
	s/((?:\$tag)?\$search)/$MATCH\$1$RESET/g ; # highlight all search
	s/\$tag(\$search)/$CURRENT\$1/ ; # highlight current
EOF

readarray -t matches <<< $(echo "$initial_command" | perl -pe "$code")

highlighted=${matches[-1]}
max_index=$(( ${#matches[@]} - 2 )) # highlighted + zero base
}

_scc_keep_position()
{
# if possible keep selection at the same place when search changes

local previous_index=$index
local previous_position=${matches[$index]}

_scc
index=0

new_index=0
for position in "${matches[@]}"
	do
	[[ "$position" == "$previous_position" ]] && index=$new_index && break
	new_index=$((new_index + 1))
	done

[[ $index !=  $previous_index ]] && _scc
}