Scan for keys with pattern using SCAN

scanpattern.py

"""
Scan for keys with a pattern in Redis. It uses SCAN command instead of KEYS. 
KEYS is dangereros as it locks down the whole server. Hence the need for SCAN

Usage:

python scanpattern.py redis.myserver.com 'KEY-PATTERN-TO-SEARCH'

"""

import redis
import time
import sys

host = sys.argv[1]
pattern = sys.argv[2]
SPEED = 10

r = redis.StrictRedis(host=host)
cursor = 0

while True:
    cursor, result = r.scan(cursor=cursor, match=pattern)
    
    if result:
        print >> sys.stderr, "Result found!"
        print "\n".join(result)
        break
    
    if cursor == 0:
        print >> sys.stderr, "All keys explored"
        break
    else:
        print >> sys.stderr, "Trying new cursor = %s" % cursor

    time.sleep(1/SPEED)