redis_bash_scan.sh

#!/usr/bin/env bash
set -eu -o pipefail

HOST=172.17.0.6
REDIS_CMD=(redis-cli -h "$HOST" scan)

CMD_EXTRA=()
if [[ ! -z ${1:-} ]]; then CMD_EXTRA+=(MATCH "$1"); fi
if [[ ! -z ${2:-} ]]; then CMD_EXTRA+=(COUNT "$2"); fi

export CMD_EXTRA

CURSOR=0

while true;
do

    CMD=("${REDIS_CMD[@]}" $CURSOR)
    if [ ${#CMD_EXTRA[@]} -gt 0 ];
    then
        CMD+=("${CMD_EXTRA[@]}")
    fi

    {
        read cursor
        CURSOR=$cursor
        while read item;
        do
            if [[ ! -z $item ]]; then echo $item; fi;
        done ;
    }< <("${CMD[@]}")

    if [ "$CURSOR" -eq 0 ]; then break; fi;
done