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Redis

There is basic Redis support in Nauthilus. Most of the time it should be enough to use simple Redis keys and string values as arguments. Type conversion can be done within Lua itself.

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

Redis custom pools

In the init script of the Nauthilus server, you can define custom pools. For each Redis command, the first parameter is either a string called "default" or a connection handle. The "default" will use Redis servers from the Nauthilus server itself.

How to register a new pool?​

Register a custom pool

Syntax​

local result, error = nauthilus_redis.register_redis_pool(name, mode, config)

Parameters​

  • name (string) - Name of the new redis pool
  • mode (string) - Defines the type of redis configuration, Possible values are:
    • standalone - Configure a simple standalone Redis instance
    • cluster - Configure a Redis cluster
    • sentinel - Configure a Redis sentinel
    • sentinel_replica - Configure a failover client primaryly for read requests
  • config (table) - The configuration parameters for the new pool
    • address (string) - Address for the standalone system (master or replica)
    • addresses (table) - List of addresses for clusters and sentinels
    • master_name (string) - Master name is for sentinels
    • sentinel_username (string) - Optional username for sentinels
    • sentinel_password (string) - Optional password for sentinels
    • username (string) - Optional username (used for standalone or sentinel setups)
    • password (string) - Optional password (used for standalone or sentinel setups)
    • db (number) - The database number in Redis
    • pool_size (number) - Maximum number of connections in the pool
    • min_idle_conns (number) - Minimum number of idle connections in the pool
    • tls_enabled (boolean) - Activates TLS support
    • tls_cert_file (string) - Optional path to a certificate file in PEM format
    • tls_key_file (string) - Optional path to a key file in PEM format

Returns​

  • result (string) - "OK" is returned, if the pool was configured successfully.
  • error (string) - An error message, if an error occurs.

Example​

local _, err_redis_reg = nauthilus_redis.register_redis_pool("my_custom_name", "sentinel", {
            addresses = { "redis-sentinel-sentinel.ot-operators:26379" },
            master_name = "myMaster",
            password = "",
            db = 3,
            pool_size = 10,
            min_idle_conns = 1,
            tls_enabled = false
        })

To get the handle of this pool, do the following in you Lua scripts:

local custom_pool, err_redis_client = nauthilus_redis.get_redis_connection("my_custom_name")

Now you can use custom_pool as the first argument to each Redis function.

You can define as many pools as you like. Currently supported is "standalone", "sentinel" and "cluster".

Documentation for the parameters is TODO.

In the following, I will use the name "handle" for a pool handler.

Functions

nauthilus_redis.redis_set​

Stores a value in Redis with an optional expiration time.

Syntax​

local result, error = nauthilus_redis.redis_set(handle, key, value, expiration)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • key (string): The Redis key to store the value under
  • value (string): The value to store
  • expiration (number, optional): Time in seconds after which the key will expire

Returns​

  • result (string): "OK" if the operation was successful
  • error (string): An error message if the operation fails

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local result, error = nauthilus_redis.redis_set(handle, "key", "value", 3600)

nauthilus_redis.redis_incr​

Increments a numeric value stored in Redis by one.

Syntax​

local number, error = nauthilus_redis.redis_incr(handle, key)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • key (string): The Redis key whose value should be incremented

Returns​

  • number (number): The new value after incrementing
  • error (string): An error message if the operation fails

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local number, error = nauthilus_redis.redis_incr(handle, "key")

nauthilus_redis.redis_get​

Retrieves a value from Redis by key.

Syntax​

local result, error = nauthilus_redis.redis_get(handle, key)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • key (string): The Redis key to retrieve the value for

Returns​

  • result (string): The value stored at the specified key
  • error (string): An error message if the operation fails

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local result, error = nauthilus_redis.redis_get(handle, "key")

nauthilus_redis.redis_expire​

Sets an expiration time (in seconds) for a Redis key.

Syntax​

local result, error = nauthilus_redis.redis_expire(handle, key, seconds)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • key (string): The Redis key to set expiration for
  • seconds (number): The expiration time in seconds

Returns​

  • result (string): "OK" if the operation was successful
  • error (string): An error message if the operation fails

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local result, error = nauthilus_redis.redis_expire(handle, "key", 3600)

nauthilus_redis.redis_del​

Deletes a key from Redis.

Syntax​

local result, error = nauthilus_redis.redis_del(handle, key)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • key (string): The Redis key to delete

Returns​

  • result (string): "OK" if the operation was successful
  • error (string): An error message if the operation fails

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local result, error = nauthilus_redis.redis_del(handle, "key")

nauthilus_redis.redis_rename​

Renames a Redis key to a new name.

Syntax​

local result, err = nauthilus_redis.redis_rename(handle, oldkey, newkey)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • oldkey (string): The current name of the Redis key
  • newkey (string): The new name for the Redis key

Returns​

  • result (string): "OK" if the operation was successful
  • err (string): An error message if the operation fails

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local oldkey = "abc"
local newkey = "def"

local result, err = nauthilus_redis.redis_rename(handle, oldkey, newkey)

nauthilus_redis.redis_hget​

Retrieves a value for a specific field from a Redis hash map.

Syntax​

local value, error = nauthilus_redis.redis_hget(handle, key, field)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • key (string): The Redis key of the hash map
  • field (string): The field name within the hash map

Returns​

  • value (string): The value of the specified field
  • error (string): An error message if the operation fails

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local redis_key = "some_key"
local already_sent_mail, err_redis_hget = nauthilus_redis.redis_hget(handle, redis_key, "send_mail")

nauthilus_redis.redis_hset​

Sets a field value in a Redis hash map.

Syntax​

local result, error = nauthilus_redis.redis_hset(handle, key, field, value)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • key (string): The Redis key of the hash map
  • field (string): The field name within the hash map
  • value (string/number): The value to set for the field

Returns​

  • result (number): 1 if field is a new field in the hash and value was set, 0 if field already exists and the value was updated
  • error (string): An error message if the operation fails

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local redis_key = "some_key"
local result, err_redis_hset = nauthilus_redis.redis_hset(handle, redis_key, "send_mail", 1)

nauthilus_redis.redis_hdel​

Deletes a field from a Redis hash map.

Syntax​

local deleted, error = nauthilus_redis.redis_hdel(handle, key, field)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • key (string): The Redis key of the hash map
  • field (string): The field name to delete from the hash map

Returns​

  • deleted (number): The number of fields that were removed (1 if successful, 0 if field did not exist)
  • error (string): An error message if the operation fails

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local result = {}
result.dovecot_session = "123"

local redis_key = "some_key"
local deleted, err_redis_hdel = nauthilus_redis.redis_hdel(handle, redis_key, result.dovecot_session)

nauthilus_redis.redis_hlen​

Gets the number of fields in a Redis hash map.

Syntax​

local length, error = nauthilus_redis.redis_hlen(handle, key)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • key (string): The Redis key of the hash map

Returns​

  • length (number): The number of fields in the hash map
  • error (string): An error message if the operation fails

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local redis_key = "some_key"
local length, err_redis_hlen = nauthilus_redis.redis_hlen(handle, redis_key)

nauthilus_redis.redis_hgetall​

Retrieves all fields and values from a Redis hash map.

Syntax​

local hash_table, error = nauthilus_redis.redis_hgetall(handle, key)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • key (string): The Redis key of the hash map

Returns​

  • hash_table (table): A Lua table containing all field-value pairs from the hash map
  • error (string): An error message if the operation fails

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local redis_key = "some_key"
local all_sessions, err_redis_hgetall = nauthilus_redis.redis_hgetall(handle, redis_key)

nauthilus_redis.redis_hincrby​

Increments the integer value of a field in a Redis hash map by a specified amount.

Syntax​

local new_value, error = nauthilus_redis.redis_hincrby(handle, key, field, increment)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • key (string): The Redis key of the hash map
  • field (string): The field name within the hash map
  • increment (number): The integer value to increment by

Returns​

  • new_value (number): The new value of the field after the increment operation
  • error (string): An error message if the operation fails

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local key = "some_key"
local field = "some_field"
local increment = 1

local new_value, err = nauthilus_redis.redis_hincrby(handle, key, field, increment)

nauthilus_redis.redis_hincrbyfloat​

Increments the floating-point value of a field in a Redis hash map by a specified amount.

Syntax​

local new_value, error = nauthilus_redis.redis_hincrbyfloat(handle, key, field, increment)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • key (string): The Redis key of the hash map
  • field (string): The field name within the hash map
  • increment (number): The floating-point value to increment by

Returns​

  • new_value (string): The new value of the field after the increment operation (as a string representation of the float)
  • error (string): An error message if the operation fails

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local key = "some_key"
local field = "some_field"
local increment = 1.3

local new_value, err = nauthilus_redis.redis_hincrbyfloat(handle, key, field, increment)

nauthilus_redis.redis_hexists​

Checks if a field exists in a Redis hash map.

Syntax​

local exists, error = nauthilus_redis.redis_hexists(handle, key, field)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • key (string): The Redis key of the hash map
  • field (string): The field name to check for existence

Returns​

  • exists (number): 1 if the field exists in the hash, 0 if it does not exist
  • error (string): An error message if the operation fails

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local key = "some_key"
local field = "some_field"

local exists, err = nauthilus_redis.redis_hexists(handle, key, field)

nauthilus_redis.redis_sadd​

Adds a member to a Redis set.

Syntax​

local added, error = nauthilus_redis.redis_sadd(handle, key, value)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • key (string): The Redis key of the set
  • value (string): The value to add to the set

Returns​

  • added (number): 1 if the member was added to the set, 0 if it was already a member
  • error (string): An error message if the operation fails

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local key = "some_key"
local value = "some_value"

local added, err = nauthilus_redis.redis_sadd(handle, key, value)

nauthilus_redis.redis_sismember​

Checks if a value is a member of a Redis set.

Syntax​

local is_member, error = nauthilus_redis.redis_sismember(handle, key, value)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • key (string): The Redis key of the set
  • value (string): The value to check for membership

Returns​

  • is_member (number): 1 if the value is a member of the set, 0 if it is not
  • error (string): An error message if the operation fails

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local key = "some_key"
local value = "some_value"

local is_member, err = nauthilus_redis.redis_sismember(handle, key, value)

nauthilus_redis.redis_smembers​

Retrieves all members from a Redis set.

Syntax​

local members, error = nauthilus_redis.redis_smembers(handle, key)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • key (string): The Redis key of the set

Returns​

  • members (table): A Lua table containing all members of the set
  • error (string): An error message if the operation fails

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local key = "some_key"

local members, err = nauthilus_redis.redis_smembers(handle, key)

nauthilus_redis.redis_srem​

Removes a member from a Redis set.

Syntax​

local removed, error = nauthilus_redis.redis_srem(handle, key, value)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • key (string): The Redis key of the set
  • value (string): The value to remove from the set

Returns​

  • removed (number): 1 if the member was removed from the set, 0 if it was not a member
  • error (string): An error message if the operation fails

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local key = "some_key"
local value = "some_value"

local removed, err = nauthilus_redis.redis_srem(handle, key, value)

nauthilus_redis.redis_scard​

Returns the number of members in a Redis set.

Syntax​

local count, error = nauthilus_redis.redis_scard(handle, key)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • key (string): The Redis key of the set

Returns​

  • count (number): The number of members in the set
  • error (string): An error message if the operation fails

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local key = "some_key"

local count, err = nauthilus_redis.redis_scard(handle, key)

nauthilus_redis.redis_upload_script​

Uploads a Lua script to a Redis server for later execution.

Syntax​

local sha1, error = nauthilus_redis.redis_upload_script(handle, script, script_name)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • script (string): The Lua script to upload to the Redis server
  • script_name (string): A name to identify the script for later execution

Returns​

  • sha1 (string): The SHA1 hash of the script, used to identify it when executing
  • error (string): An error message if the operation fails

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local script = [[
        local redis_key = KEYS[1]
        local send_mail = redis.call('HGET', redis_key, 'send_mail')

        if send_mail == false then
            redis.call('HSET', redis_key, 'send_mail', '1')

            return {'send_email', redis_key}
        else
            return {'email_already_sent'}
        end
    ]]

local upload_script_name = "nauthilus_send_mail_hash"
local sha1, err_upload = nauthilus_redis.redis_upload_script(handle, script, upload_script_name)
tip

Use an init script to upload scripts at startup

nauthilus_redis.redis_run_script​

Executes a Lua script on a Redis server, either by providing the script directly or by referencing a previously uploaded script.

Syntax​

local result, error = nauthilus_redis.redis_run_script(handle, script, script_name, keys, args)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • script (string): The Lua script to execute (leave empty if using script_name)
  • script_name (string): The name of a previously uploaded script (leave empty if providing script directly)
  • keys (table): A Lua table containing the Redis keys that will be accessed by the script
  • args (table): A Lua table containing additional arguments for the script

Returns​

  • result (any): The result returned by the executed script
  • error (string): An error message if the operation fails

Example​

local redis_key = "some_redis_key"
local script = ""
local upload_script_name = "nauthilus_send_mail_hash"

-- Set either script or upload_script_name!
local script_result, err_run_script = nauthilus_redis.redis_run_script(handle, script, upload_script_name, { redis_key }, {})
note

If running a script, you must set the upload-script-name to ""

nauthilus_redis.redis_zadd​

New in version 1.4.10

Adds members with their associated scores to a Redis Sorted Set.

Syntax​

local result, err = nauthilus_redis.redis_zadd(key, members)

Parameters​

  • key (string): The name of the Redis Sorted Set.
  • members (table): A Lua table where:
    • Keys are the members (strings).
    • Values are the scores (numbers).

Returns​

  • result (number): The total number of members successfully added.
  • err (string): An error message, if an error occurs.

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local added, err = nauthilus_redis.redis_zadd("my_sorted_set", { member1 = 10, member2 = 20 })
if err then
    print("Error:", err)
else
    print("Added elements:", added)
end

nauthilus_redis.redis_zrange​

New in version 1.4.10

Retrieves a subset of elements from a Redis Sorted Set based on an index range (in ascending order).

Syntax​

local elements, err = nauthilus_redis.redis_zrange(key, start, stop)

Parameters​

  • key (string): The name of the Redis Sorted Set.
  • start (number): The starting index of the range.
  • stop (number): The stopping index of the range.

Returns​

  • elements (table): A Lua table containing the retrieved elements.
  • err (string): An error message, if an error occurs.

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local elements, err = nauthilus_redis.redis_zrange("my_sorted_set", 0, -1)
if err then
    print("Error:", err)
else
    for _, val in ipairs(elements) do
        print(val)
    end
end

nauthilus_redis.redis_zrevrange​

New in version 1.4.10

Retrieves a subset of elements from a Redis Sorted Set in descending order based on an index range.

Syntax​

local elements, err = nauthilus_redis.redis_zrevrange(key, start, stop)

Parameters​

  • key (string): The name of the Redis Sorted Set.
  • start (number): The starting index of the range.
  • stop (number): The stopping index of the range.

Returns​

  • elements (table): A Lua table containing the retrieved elements.
  • err (string): An error message, if an error occurs.

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local elements, err = nauthilus_redis.redis_zrevrange("my_sorted_set", 0, -1)
if err then
    print("Error:", err)
else
    for _, val in ipairs(elements) do
        print(val)
    end
end

nauthilus_redis.redis_zrangebyscore​

New in version 1.4.10

Retrieves elements within a score range from a Redis Sorted Set. Optional pagination is supported.

Syntax​

local elements, err = nauthilus_redis.redis_zrangebyscore(key, min_score, max_score, options)

Parameters​

  • key (string): The name of the Redis Sorted Set.
  • min_score (number): The lower bound of the score range.
  • max_score (number): The upper bound of the score range.
  • options (table, optional): A Lua table for optional pagination:
    • offset (number): The starting position of the results.
    • count (number): The maximum number of results retrieved.

Returns​

  • elements (table): A Lua table containing the retrieved elements.
  • err (string): An error message, if an error occurs.

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local elements, err = nauthilus_redis.redis_zrangebyscore("my_sorted_set", 10, 50, { offset = 0, count = 5 })
if err then
    print("Error:", err)
else
    for _, val in ipairs(elements) do
        print(val)
    end
end

nauthilus_redis.redis_zrem​

New in version 1.4.10

Removes members from a Redis Sorted Set.

Syntax​

local result, err = nauthilus_redis.redis_zrem(key, members)

Parameters​

  • key (string): The name of the Redis Sorted Set.
  • members (table): A Lua table containing the members (as strings) to be removed.

Returns​

  • result (number): The number of members successfully removed.
  • err (string): An error message, if an error occurs.

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local removed, err = nauthilus_redis.redis_zrem("my_sorted_set", { "member1", "member2" })
if err then
    print("Error:", err)
else
    print("Removed elements:", removed)
end

nauthilus_redis.redis_zrank​

New in version 1.4.10

Gets the rank of a member in a Redis Sorted Set, with scores sorted in ascending order.

Syntax​

local rank, err = nauthilus_redis.redis_zrank(key, member)

Parameters​

  • key (string): The name of the Redis Sorted Set.
  • member (string): The member whose rank you want to retrieve.

Returns​

  • rank (number): The rank of the member (0-based index).
  • err (string): An error message, if an error occurs.

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local rank, err = nauthilus_redis.redis_zrank("my_sorted_set", "member1")
if err then
    print("Error:", err)
else
    print("Rank of member:", rank)
end

nauthilus_redis.redis_zremrangebyscore​

New in version 1.4.10

Removes all members within a given score range from a Redis Sorted Set.

Syntax​

local result, err = nauthilus_redis.redis_zremrangebyscore(key, min_score, max_score)

Parameters​

  • key (string): The name of the Redis Sorted Set.
  • min_score (number): The lower bound of the score range.
  • max_score (number): The upper bound of the score range.

Returns​

  • result (number): The number of members removed.
  • err (string): An error message, if an error occurs.

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local removed, err = nauthilus_redis.redis_zremrangebyscore("my_sorted_set", 10, 20)
if err then
    print("Error:", err)
else
    print("Removed elements:", removed)
end

nauthilus_redis.redis_zcount​

New in version 1.7.7

Counts the number of members in a Redis Sorted Set with scores between min and max.

Syntax​

local count, err = nauthilus_redis.redis_zcount(handle, key, min, max)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • key (string): The name of the Redis Sorted Set
  • min (string): The minimum score (can be a number or "-inf")
  • max (string): The maximum score (can be a number or "+inf")

Returns​

  • count (number): The number of members in the specified score range
  • err (string): An error message, if an error occurs

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local count, err = nauthilus_redis.redis_zcount("default", "my_sorted_set", "10", "20")
if err then
    print("Error:", err)
else
    print("Number of members in range:", count)
end

nauthilus_redis.redis_zscore​

New in version 1.7.7

Retrieves the score of a member in a Redis Sorted Set.

Syntax​

local score, err = nauthilus_redis.redis_zscore(handle, key, member)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • key (string): The name of the Redis Sorted Set
  • member (string): The member whose score you want to retrieve

Returns​

  • score (number): The score of the member in the sorted set
  • err (string): An error message if the operation fails or if the member does not exist

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local score, err = nauthilus_redis.redis_zscore("default", "my_sorted_set", "member1")
if err then
    print("Error:", err)
else
    print("Score of member:", score)
end

nauthilus_redis.redis_lpush​

New in version 1.7.7

Adds one or more values to the beginning of a Redis list and returns the length of the list after the push operation.

Syntax​

local length, error = nauthilus_redis.redis_lpush(handle, key, value1, value2, ...)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • key (string): The Redis key of the list
  • value1 (string/number): The first value to add to the beginning of the list
  • value2, ... (string/number, optional): Additional values to add to the beginning of the list

Returns​

  • length (number): The length of the list after the push operation
  • error (string): An error message if the operation fails

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local length, err = nauthilus_redis.redis_lpush("default", "my_list", "value1", "value2")
if err then
    print("Error:", err)
else
    print("List length after push:", length)
end

nauthilus_redis.redis_rpush​

New in version 1.7.7

Adds one or more values to the end of a Redis list and returns the length of the list after the push operation.

Syntax​

local length, error = nauthilus_redis.redis_rpush(handle, key, value1, value2, ...)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • key (string): The Redis key of the list
  • value1 (string/number): The first value to add to the end of the list
  • value2, ... (string/number, optional): Additional values to add to the end of the list

Returns​

  • length (number): The length of the list after the push operation
  • error (string): An error message if the operation fails

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local length, err = nauthilus_redis.redis_rpush("default", "my_list", "value1", "value2")
if err then
    print("Error:", err)
else
    print("List length after push:", length)
end

nauthilus_redis.redis_lpop​

New in version 1.7.7

Removes and returns the first element of a Redis list.

Syntax​

local value, error = nauthilus_redis.redis_lpop(handle, key)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • key (string): The Redis key of the list

Returns​

  • value (string): The value of the first element of the list
  • error (string): An error message if the operation fails

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local value, err = nauthilus_redis.redis_lpop("default", "my_list")
if err then
    print("Error:", err)
else
    print("Popped value:", value)
end

nauthilus_redis.redis_rpop​

New in version 1.7.7

Removes and returns the last element of a Redis list.

Syntax​

local value, error = nauthilus_redis.redis_rpop(handle, key)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • key (string): The Redis key of the list

Returns​

  • value (string): The value of the last element of the list
  • error (string): An error message if the operation fails

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local value, err = nauthilus_redis.redis_rpop("default", "my_list")
if err then
    print("Error:", err)
else
    print("Popped value:", value)
end

nauthilus_redis.redis_lrange​

New in version 1.7.7

Returns a range of elements from a Redis list.

Syntax​

local elements, error = nauthilus_redis.redis_lrange(handle, key, start, stop)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • key (string): The Redis key of the list
  • start (number): The starting index of the range (0-based)
  • stop (number): The ending index of the range (inclusive, can be negative to count from the end)

Returns​

  • elements (table): A Lua table containing the elements in the specified range
  • error (string): An error message if the operation fails

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local elements, err = nauthilus_redis.redis_lrange("default", "my_list", 0, -1)
if err then
    print("Error:", err)
else
    for i, value in ipairs(elements) do
        print(i, value)
    end
end

nauthilus_redis.redis_llen​

New in version 1.7.7

Returns the length of a Redis list.

Syntax​

local length, error = nauthilus_redis.redis_llen(handle, key)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • key (string): The Redis key of the list

Returns​

  • length (number): The length of the list
  • error (string): An error message if the operation fails

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local length, err = nauthilus_redis.redis_llen("default", "my_list")
if err then
    print("Error:", err)
else
    print("List length:", length)
end

nauthilus_redis.redis_mget​

New in version 1.7.7

Retrieves the values of multiple keys from Redis.

Syntax​

local values, error = nauthilus_redis.redis_mget(handle, key1, key2, ...)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • key1, key2, ... (string): One or more Redis keys to retrieve values for

Returns​

  • values (table): A Lua table where keys are the Redis keys and values are the corresponding values
  • error (string): An error message if the operation fails

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local values, err = nauthilus_redis.redis_mget("default", "key1", "key2", "key3")
if err then
    print("Error:", err)
else
    for key, value in pairs(values) do
        print(key, value)
    end
end

nauthilus_redis.redis_mset​

New in version 1.7.7

Sets multiple key-value pairs in Redis.

Syntax​

local result, error = nauthilus_redis.redis_mset(handle, key1, value1, key2, value2, ...)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • key1, value1, key2, value2, ... (string/number): Key-value pairs to set in Redis

Returns​

  • result (string): "OK" if the operation was successful
  • error (string): An error message if the operation fails

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local result, err = nauthilus_redis.redis_mset("default", "key1", "value1", "key2", "value2")
if err then
    print("Error:", err)
else
    print("Result:", result)
end

nauthilus_redis.redis_keys​

New in version 1.7.7

Returns all keys matching a pattern.

Syntax​

local keys, error = nauthilus_redis.redis_keys(handle, pattern)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • pattern (string): The pattern to match keys against (e.g., "user:*")

Returns​

  • keys (table): A Lua table containing all keys matching the pattern
  • error (string): An error message if the operation fails

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local keys, err = nauthilus_redis.redis_keys("default", "user:*")
if err then
    print("Error:", err)
else
    for i, key in ipairs(keys) do
        print(i, key)
    end
end
warning

The KEYS command should be used with caution in production environments as it may impact performance when executed against large databases.

nauthilus_redis.redis_scan​

New in version 1.7.7

Incrementally iterates over keys in Redis.

Syntax​

local result, error = nauthilus_redis.redis_scan(handle, cursor, match, count)

Parameters​

  • handle (userdata/string): Redis connection handle or "default" for the default connection
  • cursor (number): The cursor to start the scan from (use 0 for the first call)
  • match (string, optional): The pattern to match keys against (default: "*")
  • count (number, optional): The number of keys to return per call (default: 10)

Returns​

  • result (table): A Lua table with two fields:
    • cursor (number): The cursor to use for the next scan (0 when the scan is complete)
    • keys (table): A Lua table containing the keys found in this scan
  • error (string): An error message if the operation fails

Example​

dynamic_loader("nauthilus_redis")
local nauthilus_redis = require("nauthilus_redis")

local cursor = 0
repeat
    local result, err = nauthilus_redis.redis_scan("default", cursor, "user:*", 10)
    if err then
        print("Error:", err)
        break
    end

    cursor = result.cursor

    for i, key in ipairs(result.keys) do
        print(i, key)
    end
until cursor == 0
tip

The SCAN command is the recommended way to iterate over keys in a production environment as it has minimal impact on performance.