[shell] scan.sh

#!/bin/bash
 
if [ "$#" -lt 2 ] 
then
  echo "Scan keys in Redis matching a pattern using SCAN (safe version of KEYS)"
  echo "Usage: $0 <host> [port] [database] [pattern]"
  exit 1
fi
host=${1:-}
port=${2:-6379}
database=${3:-0}
pattern=${3:-\*}
cursor=-1
keys=""
 
while [[ "$cursor" -ne 0 ]]; do
  if [[ "$cursor" -eq -1 ]]
  then
    cursor=0
  fi
 
  reply=$(redis-cli -h "$host" -p "$port" -n "$database" SCAN "$cursor" MATCH "$pattern")
  cursor=$(expr "$reply" : '\([0-9]*[0-9 ]\)')
  keys=${reply##[0-9]*[0-9 ]}
  echo $keys
done