lua-hiredis — Bindings for hiredis Redis-client library

See the copyright information in the file named COPYRIGHT.

API

• hiredis.connect(host : string, port : number) : conn / nil, err, error_code

• hiredis.unwrap_reply(reply) : reply / name, hiredis.REPLY_STATUS / nil, err

  • If reply is a hiredis.REPLY_ERROR object, returns nil, reply.name.
  • If reply is a hiredis.REPLY_STATUS object, returns reply.name, hiredis.REPLY_STATUS (It is guaranteed that reply.name is not nil or false.)
  • Returns reply itself otherwise (note that hiredis.REPLY_NIL object is not unwrapped).

Connection

• conn:command(... : string) : reply / nil, err, error_code

• conn:append_command(... : string) : (nothing)

• conn:get_reply() : reply / nil, err, error_code

• conn:close() : (nothing)

Error-code

Hiredis error codes (see docs), also available as hiredis.ERR_<something>:

• REDIS_ERR_IO is hiredis.ERR_IO,
• REDIS_ERR_EOF is hiredis.ERR_EOF,
• REDIS_ERR_PROTOCOL is hiredis.ERR_PROTOCOL,
• REDIS_ERR_OTHER is hiredis.ERR_OTHER.

Reply

• REDIS_REPLY_STATUS is a const-object (see below) with type hiredis.REPLY_STATUS. Common status objects are available in hiredis module table:

  • hiredis.OK
  • hiredis.QUEUED
  • hiredis.PONG

  It is guaranteed that these object instances are always used for their corresponding statuses (so you can make a simple equality check).

• REDIS_REPLY_ERROR is a const-object with type hiredis.REPLY_ERROR. Note that Redis server errors are returned as REDIS_REPLY_ERROR values, not as nil, err, error_code triplet. See tests for example.

• REDIS_REPLY_INTEGER is a Lua number.

• REDIS_REPLY_NIL is a const-object with type hiredis.REPLY_NIL.

• REDIS_REPLY_STRING is a binary-safe Lua string.

• REDIS_REPLY_ARRAY is a linear Lua table (nesting is supported).

Const-object

Const-object is a table with fields name and type.

There are three types of const-objects:

• hiredis.REPLY_NIL (only a single instance is ever used: hiredis.NIL)
• hiredis.REPLY_ERROR
• hiredis.REPLY_STATUS

Use hiredis.unwrap_reply() to convert const-object to regular Lua value.

Note: Unwrapping is not done automatically to make array reply handling more straightforward.

More information

Read test/test.lua for examples. Read hiredis README for API motivation.