PHP Predis: how to get/delete keys containing special characters?

Question

I need to delete a key containing some special keys (in my case square brackets):

I do the following, but it does not work:

$this->redis;    
$keys = $this->redis->keys("*");
foreach ($keys as $key) {

    // keys are in the following format:   
    //    vir3_data_cache[zones_cdc_shifting_series_2013_5][1]

    $this->redis->del($key);
    // no key was deleted
}

I also tried to quote the key, but without success:

$this->redis;    
$keys = $this->redis->keys("*");
foreach ($keys as $key) {

    // keys are in the following format:   
    //    vir3_data_cache[zones_cdc_shifting_series_2013_5][1]

    $quotedKey = addslashes(addslashes($key));
    $this->redis->del($quotedKey);
    // no key was deleted
}

@nmallare as you suggested, I tried to do `$this->redis->del("'vir3_data_cache[zones_cdc_shifting_series_2013_5][1]'")` but it does not work — fdellutri, Aug 29 '14 at 10:02

score 3 · Accepted Answer · answered Aug 29 '14 at 10:38

Solved. The problem was related to the fact that predis insert automatically a configured prefix at the beginning of each key (in my case 'vir3_data_cache') before doing any operation. But the keys("*") command does not strip off the prefix from the key.

So I need to do the following in order to make my code work:

$prefix = $this->redis->getOptions()->__get('prefix')->getPrefix();

$keys = $this->redis->keys("*");
$removed = 0;
foreach ($keys as $key) {
    if (substr($key, 0, strlen($prefix)) == $prefix) {
        $key = substr($key, strlen($prefix));
    }              
}

score 1 · Answer 2 · answered Sep 01 '17 at 13:24

When using phpredis, you can get the prefix and delete a pattern of keys that way :

<?php
...

$prefix = $redisClient->getOption(Redis::OPT_PREFIX);
$redisClient->delete(array_map(
    function ($key) use ($prefix) {
        return str_replace($prefix, '', $key);
    }, $redisClient->keys('*'))
);

PHP Predis: how to get/delete keys containing special characters?

2 Answers2