FUNCTION LOAD

Syntax text Syntax diagram API methods

FUNCTION LOAD [REPLACE] function-code

Client:

function_load(
    code: str,  // Function library code
    replace: Optional[bool]  // Replace existing library if it exists
) → Union[Awaitable[str], str]  // Library name

functionLoad(
    code: RedisArgument,  // Library code to load
    options: FunctionLoadOptions  // Function load options
) → Promise<BlobStringReply>  // Library name

functionLoad(
    functionCode: String  // Function library code
) → String  // Library name

functionLoadReplace(
    functionCode: String  // Function library code
) → String  // Library name

functionLoad(
    functionCode: String  // Function library code
) → String  // Library name

functionLoad(
    functionCode: String,  // Function library code
    replace: boolean  // Replace existing library if it exists
) → String  // Library name

functionLoad(
    functionCode: String  // Function library code
) → RedisFuture<String>  // Library name

functionLoad(
    functionCode: String,  // Function library code
    replace: boolean  // Replace existing library if it exists
) → RedisFuture<String>  // Library name

functionLoad(
    functionCode: String  // Function library code
) → Mono<String>  // Library name

functionLoad(
    functionCode: String,  // Function library code
    replace: boolean  // Replace existing library if it exists
) → Mono<String>  // Library name

FunctionLoad(
    ctx: context.Context,  // Context for the operation
    code: string  // Function library code
) → *StringCmd  // Library name

FunctionLoadReplace(
    ctx: context.Context,  // Context for the operation
    code: string  // Function library code
) → *StringCmd  // Library name

Available since:: Redis Open Source 7.0.0
Time complexity:: O(1) (considering compilation time is redundant)
ACL categories:: @write, @slow, @scripting,
Compatibility:: Redis Software and Redis Cloud compatibility

Load a library to Redis.

The command takes one required parameter: the source code that implements the library. The library payload must start with a shebang statement that provides the library metadata, including the engine to use and the library name.

Use this shebang format:

#!<engine name> name=<library name>.

Currently, <engine name> must be lua.

For the Lua engine, the implementation should declare one or more entry points to the library with the redis.register_function() API. Once loaded, you can call the functions in the library with the FCALL or FCALL_RO commands, as appropriate.

For more information please refer to Introduction to Redis Functions.

Required arguments

function-code

The library's source code. It must begin with a Shebang statement that declares the engine and library name, for example #!lua name=mylib.

Optional arguments

REPLACE

Replace an existing library that has the same name.

Examples

The following example will create a library named mylib with a single function, myfunc, that returns the first argument it gets.

redis> FUNCTION LOAD "#!lua name=mylib \n redis.register_function('myfunc', function(keys, args) return args[1] end)"
mylib
redis> FCALL myfunc 0 hello
"hello"

Redis Software and Redis Cloud compatibility

Redis Software	Redis Cloud	Notes
✅ Standard ✅ Active-Active	✅ Standard ✅ Active-Active

Return information

RESP2 RESP3

One of the following:

Bulk string reply: the library name that was loaded.
Simple error string in the following circumstances: an invalid engine-name was provided, the library's name already exists without the REPLACE modifier, a function in the library is created with a name that already exists in another library (even when REPLACE is specified), the engine failed in creating the library's functions (for example, because of a compilation error), or no functions were declared by the library.

One of the following:

Bulk string reply: the library name that was loaded.
Simple error string in the following circumstances: an invalid engine-name was provided, the library's name already exists without the REPLACE modifier, a function in the library is created with a name that already exists in another library (even when REPLACE is specified), the engine failed in creating the library's functions (for example, because of a compilation error), or no functions were declared by the library.