BITFIELD_RO - Upstash Documentation

Use BITFIELD_RO to read one or more bitfield values without modifying the key.

It is the read-only form of BITFIELD and accepts GET operations only, so it is safe to run on replicas and from read-only scripts. Each GET names an encoding, u<bits> for unsigned or i<bits> for signed integers, and a bit offset that can be written as #<n> to address the n-th field of that width. The reply holds one integer per GET, and any part of a field that lies past the end of the stored string reads as zero.

Syntax#

BITFIELD_RO <key> [GET <encoding> <offset> [GET <encoding> <offset> ...]]

Arguments#

Argument	Required	Repeatable	Description
`<key>`	Yes	No	Redis key targeted by the command.
`GET <encoding> <offset>`	No	Yes	Read the value at `<offset>` using `<encoding>`, such as `u8` or `i16`. Repeat to read several fields.

Response#

The reply reports the result of the operation. Error replies have the same shape in RESP2 and RESP3 and are surfaced as exceptions by the SDKs below.

Protocol	Reply
RESP2	Array of integer or null replies, one per subcommand
RESP3	Array of integer or null replies, one per subcommand

Note

Client libraries often decode bulk strings, maps, sets, and numeric strings into language-native values. The table describes the Redis wire reply.

Examples#

TCP examples use the TLS REDIS_URL from the Upstash console. REST examples use UPSTASH_REDIS_REST_URL and UPSTASH_REDIS_REST_TOKEN.

Redis CLI

BITFIELD_RO my-key GET u8 0

@upstash/redis

Note

This command is not supported yet in @upstash/redis.

upstash_redis

from upstash_redis import Redisredis = Redis.from_env()result = redis.bitfield_ro("my-key").get("u8", 0).execute()print(result)

ioredis

import Redis from "ioredis";const redis = new Redis(process.env.REDIS_URL!);const result = await redis.bitfield_ro("my-key", "GET", "u8", "0");console.log(result);

node-redis

import { createClient } from "redis";const client = await createClient({ url: process.env.REDIS_URL })  .on("error", console.error)  .connect();const result = await client.bitFieldRo("my-key", [{ encoding: "u8", offset: 0 }]);console.log(result);

redis-py

import osimport redisclient = redis.from_url(os.environ["REDIS_URL"])result = client.bitfield_ro("my-key", "u8", 0)print(result)

go-redis

package mainimport (    "context"    "fmt"    "os"    "github.com/redis/go-redis/v9")func main() {    opts, err := redis.ParseURL(os.Getenv("REDIS_URL"))    if err != nil {        panic(err)    }    client := redis.NewClient(opts)    result, err := client.BitFieldRO(context.Background(), "my-key", "GET", "u8", 0).Result()    if err != nil {        panic(err)    }    fmt.Println(result)}

jedis

import java.net.URI;import redis.clients.jedis.Jedis;try (Jedis jedis = new Jedis(new URI(System.getenv("REDIS_URL")))) {  Object result = jedis.bitfieldReadonly("my-key", "GET", "u8", "0");  System.out.println(result);}

redis-rs

fn main() -> redis::RedisResult<()> {    let url = std::env::var("REDIS_URL").expect("REDIS_URL is not set");    let client = redis::Client::open(url)?;    let mut connection = client.get_connection()?;    let mut command = redis::cmd("BITFIELD_RO");    command.arg("my-key");    let result: redis::Value = command.query(&mut connection)?;    println!("{result:?}");    Ok(())}