getRange (substr also supported but deprecated in redis)
Description
Return a substring of a larger string
返回字符串的一部分
Parameters
key start end
Return value
STRING: the substring
Example
$redis->set('key', 'string value');
$redis->getRange('key', 0, 5); /* 'string' */
$redis->getRange('key', -5, -1); /* 'value' */