Redis 命令 - Strings

APPEND key value

Available since 2.0.0, Time complexity: O(1).

Append a value to a key

127.0.0.1:6379> SET foo hello
OK
127.0.0.1:6379> APPEND foo world
(integer) 10
127.0.0.1:6379> GET foo
"helloworld"
127.0.0.1:6379> APPEND bar hello
(integer) 5
127.0.0.1:6379> GET bar
"hello"

More: http://redis.io/commands/append, http://www.redis.cn/commands/append.html

BITCOUNT key [start end]

Count set bits in a string

127.0.0.1:6379> SET foo hello
OK
127.0.0.1:6379> BITCOUNT foo
(integer) 21

More: http://redis.io/commands/bitcount, http://www.redis.cn/commands/bitcount.html

BITOP operation destkey key [key ...]

Perform bitwise operations between strings

127.0.0.1:6379> SET key1 aba
OK
127.0.0.1:6379> SET key2 abb
OK
127.0.0.1:6379> BITOP OR dest key1 key2
(integer) 3
127.0.0.1:6379> GET dest
"abc"

More: http://redis.io/commands/bitop, http://www.redis.cn/commands/bitop.html

BITPOS key bit [start] [end]

Find first bit set or clear in a string

127.0.0.1:6379> SET foo "\xff\xf0\x00"
OK
127.0.0.1:6379> BITPOS foo 0
(integer) 12
127.0.0.1:6379> SET foo "\x00\xff\xf0"
OK
127.0.0.1:6379> BITPOS foo 1
(integer) 8

More: http://redis.io/commands/bitpos

DECR key

Decrement the integer value of a key by one

127.0.0.1:6379> SET foo 10
OK
127.0.0.1:6379> DECR foo
(integer) 9
127.0.0.1:6379> DECR foo
(integer) 8
127.0.0.1:6379> DECR bar
(integer) -1

More: http://redis.io/commands/decr, http://www.redis.cn/commands/decr.html

DECRBY key decrement

Decrement the integer value of a key by the given number

127.0.0.1:6379> SET foo 10
OK
127.0.0.1:6379> DECRBY foo 3
(integer) 7
127.0.0.1:6379> DECRBY foo 4
(integer) 3

More: http://redis.io/commands/decrby, http://www.redis.cn/commands/decrby.html

GET key

Get the value of a key

127.0.0.1:6379> GET foo
(nil)
127.0.0.1:6379> SET foo hello
OK
127.0.0.1:6379> GET foo
"hello"

More: http://redis.io/commands/get, http://www.redis.cn/commands/get.html

GETBIT key offset

Returns the bit value at offset in the string value stored at key

# binary of code a's ASCII is 01100001
127.0.0.1:6379> SET foo a
OK
127.0.0.1:6379> GETBIT foo 0
(integer) 0
127.0.0.1:6379> GETBIT foo 1
(integer) 1
127.0.0.1:6379> GETBIT foo 2
(integer) 1
127.0.0.1:6379> GETBIT foo 3
(integer) 0
127.0.0.1:6379> GETBIT foo 4
(integer) 0
127.0.0.1:6379> GETBIT foo 5
(integer) 0
127.0.0.1:6379> GETBIT foo 6
(integer) 0
127.0.0.1:6379> GETBIT foo 7
(integer) 1

More: http://redis.io/commands/getbit, http://www.redis.cn/commands/getbit.html

GETRANGE key start end

Get a substring of the string stored at a key

127.0.0.1:6379> SET foo helloworld
OK
127.0.0.1:6379> GETRANGE foo 0 3
"hell"
127.0.0.1:6379> GETRANGE foo 3 5
"low"
127.0.0.1:6379> GETRANGE foo 5 -1
"world"

More: http://redis.io/commands/getrange, http://www.redis.cn/commands/getrange.html

GETSET key value

Set the string value of a key and return its old value

127.0.0.1:6379> SET foo hello
OK
127.0.0.1:6379> GETSET foo world
"hello"
127.0.0.1:6379> GET foo
"world"

More: http://redis.io/commands/getset, http://www.redis.cn/commands/getset.html

INCR key

Increment the integer value of a key by one

127.0.0.1:6379> SET foo 10
OK
127.0.0.1:6379> INCR foo
(integer) 11
127.0.0.1:6379> INCR foo
(integer) 12
127.0.0.1:6379> INCR bar
(integer) 1

More: http://redis.io/commands/incr, http://www.redis.cn/commands/incr.html

INCRBY key increment

Increment the integer value of a key by the given amount

127.0.0.1:6379> SET foo 10
OK
127.0.0.1:6379> INCRBY foo 2
(integer) 12
127.0.0.1:6379> INCRBY foo 3
(integer) 15
127.0.0.1:6379> INCRBY bar 4
(integer) 4

More: http://redis.io/commands/incrby, http://www.redis.cn/commands/incrby.html

INCRBYFLOAT key increment

Increment the float value of a key by the given amount

127.0.0.1:6379> SET foo 10
OK
127.0.0.1:6379> INCRBYFLOAT foo 2.3
"12.3"
127.0.0.1:6379> INCRBYFLOAT foo 5.8E2
"592.29999999999999999"
127.0.0.1:6379>
127.0.0.1:6379> INCRBYFLOAT bar 3.33
"3.33"

More: http://redis.io/commands/incrbyfloat, http://www.redis.cn/commands/incrbyfloat.html

MGET key [key ...]

Get the values of all the given keys

127.0.0.1:6379> SET foo hello
OK
127.0.0.1:6379> SET bar world
OK
127.0.0.1:6379> MGET foo bar
1) "hello"
2) "world"

More: http://redis.io/commands/mget, http://www.redis.cn/commands/mget.html

MSET key value [key value ...]

Set multiple keys to multiple values

127.0.0.1:6379> MSET foo hello bar world
OK
127.0.0.1:6379> MGET foo bar
1) "hello"
2) "world"

More: http://redis.io/commands/mset, http://www.redis.cn/commands/mset.html

MSETNX key value [key value ...]

Set multiple keys to multiple values, only if none of the keys exist

127.0.0.1:6379> SET foo hello
OK
127.0.0.1:6379> MSETNX foo world bar world
(integer) 0
127.0.0.1:6379> MGET foo bar
1) "hello"
2) (nil)

More: http://redis.io/commands/msetnx, http://www.redis.cn/commands/msetnx.html

PSETEX key milliseconds value

Set the value and expiration in milliseconds of a key

127.0.0.1:6379> PSETEX foo 10000 hello
OK
127.0.0.1:6379> PTTL foo
(integer) 8404
127.0.0.1:6379> GET foo
"hello"
127.0.0.1:6379> PTTL foo
(integer) -2
127.0.0.1:6379> GET foo
(nil)

More: http://redis.io/commands/psetex, http://www.redis.cn/commands/psetex.html

SET key value [EX seconds] [PX milliseconds] [NX|XX]

Set the string value of a key

127.0.0.1:6379> SET foo hello
OK
127.0.0.1:6379> GET foo
"hello"

More: http://redis.io/commands/set, http://www.redis.cn/commands/set.html

SETBIT key offset value

Sets or clears the bit at offset in the string value stored at key

127.0.0.1:6379> SET foo a
OK
127.0.0.1:6379> GETBIT foo 7
(integer) 1
127.0.0.1:6379> SETBIT foo 7 0
(integer) 1

More: http://redis.io/commands/setbit, http://www.redis.cn/commands/setbit.html

SETEX key seconds value

Set the value and expiration of a key

127.0.0.1:6379> SETEX foo 10 hello
OK
127.0.0.1:6379> TTL foo
(integer) 8
127.0.0.1:6379> GET foo
"hello"
127.0.0.1:6379> TTL foo
(integer) -2
127.0.0.1:6379> GET foo
(nil)

More: http://redis.io/commands/setex, http://www.redis.cn/commands/setex.html

SETNX key value

Set the value of a key, only if the key does not exist

127.0.0.1:6379> SETNX foo hello
(integer) 1
127.0.0.1:6379> GET foo
"hello"
127.0.0.1:6379> SETNX foo world
(integer) 0
127.0.0.1:6379> GET foo
"hello"

More: http://redis.io/commands/setnx, http://www.redis.cn/commands/msetnx.html

SETRANGE key offset value

Overwrite part of a string at key starting at the specified offset

127.0.0.1:6379> SET foo helloworld
OK
127.0.0.1:6379> SETRANGE foo 5 redis
(integer) 10
127.0.0.1:6379> GET foo
"helloredis"

More: http://redis.io/commands/setrange, http://www.redis.cn/commands/setrange.html

STRLEN key

Get the length of the value stored in a key

127.0.0.1:6379> set foo hello
OK
127.0.0.1:6379> STRLEN foo
(integer) 5

More: http://redis.io/commands/strlen, http://www.redis.cn/commands/strlen.html