Redis Client Connect Test

CLIENT LIST

The CLIENT LIST command returns information and statistics about the client connections server in a mostly human readable format.

Return value

Bulk string reply: a unique string, formatted as follows:

• One client connection per line (separated by LF)
• Each line is composed of a succession of property=value fields separated by a space character.

Here is the meaning of the fields:

• id: an unique 64-bit client ID (introduced in Redis 2.8.12).
• addr: address/port of the client
• fd: file descriptor corresponding to the socket
• age: total duration of the connection in seconds
• idle: idle time of the connection in seconds
• flags: client flags (see below)
• db: current database ID
• sub: number of channel subscriptions
• psub: number of pattern matching subscriptions
• multi: number of commands in a MULTI/EXEC context
• qbuf: query buffer length (0 means no query pending)
• qbuf-free: free space of the query buffer (0 means the buffer is full)
• obl: output buffer length
• oll: output list length (replies are queued in this list when the buffer is full)
• omem: output buffer memory usage
• events: file descriptor events (see below)
• cmd: last command played

The client flags can be a combination of:

O: the client is a slave in MONITOR mode
S: the client is a normal slave server
M: the client is a master
x: the client is in a MULTI/EXEC context
b: the client is waiting in a blocking operation
i: the client is waiting for a VM I/O (deprecated)
d: a watched keys has been modified - EXEC will fail
c: connection to be closed after writing entire reply
u: the client is unblocked
U: the client is connected via a Unix domain socket
r: the client is in readonly mode against a cluster node
A: connection to be closed ASAP
N: no specific flag set

The file descriptor events can be:

r: the client socket is readable (event loop)
w: the client socket is writable (event loop)

example for pub/sub

https://github.com/redis/hiredis/issues/55 aluiken commented on Mar 2, 2012

void onMessage(redisAsyncContext *c, void *reply, void *privdata) {
    redisReply *r = reply;
    if (reply == NULL) return;

    if (r->type == REDIS_REPLY_ARRAY) {
        for (int j = 0; j < r->elements; j++) {
            printf("%u) %s\n", j, r->element[j]->str);
        }
    }
}

int main (int argc, char **argv) {
    signal(SIGPIPE, SIG_IGN);
    struct event_base *base = event_base_new();

    redisAsyncContext *c = redisAsyncConnect("127.0.0.1", 6379);
    if (c->err) {
        printf("error: %s\n", c->errstr);
        return 1;
    }

    redisLibeventAttach(c, base);
    redisAsyncCommand(c, onMessage, NULL, "SUBSCRIBE testtopic");
    event_base_dispatch(base);
    return 0;
}

hiredis MFC import

Hiredis is a minimalistic C client library for the Redis database.

It is minimalistic because it just adds minimal support for the protocol, but at the same time it uses a high level printf-alike API in order to make it much higher level than otherwise suggested by its minimal code base and the lack of explicit bindings for every Redis command.

1. Download Hiredis

Project Site : https://github.com/redis/hiredis

[Clone or download] [Download ZIP]

2. Include Hiredis Header Files

3. Config Hiredis Header Files Path

4. Build Hiredis Library File

Open Hiredis Project

5. Config Hiredis Library File Path

6. Sample Code

#include 
#include 
#include 

#include "hiredis.h"

#ifdef HIREDIS_WIN
#define snprintf sprintf_s
#endif

int main(void) {
    unsigned int j;
    redisContext *c;
    redisReply *reply;

    struct timeval timeout = { 1, 500000 }; // 1.5 seconds
    c = redisConnectWithTimeout((char*)"127.0.0.1", 6379, timeout);
    if (c->err) {
        printf("Connection error: %s\n", c->errstr);
        exit(1);
    }

    /* PING server */
    reply = redisCommand(c,"PING");
    printf("PING: %s\n", reply->str);
    freeReplyObject(reply);

    /* Set a key */
    reply = redisCommand(c,"SET %s %s", "foo", "hello world");
    printf("SET: %s\n", reply->str);
    freeReplyObject(reply);

    /* Set a key using binary safe API */
    reply = redisCommand(c,"SET %b %b", "bar", 3, "hello", 5);
    printf("SET (binary API): %s\n", reply->str);
    freeReplyObject(reply);

    /* Try a GET and two INCR */
    reply = redisCommand(c,"GET foo");
    printf("GET foo: %s\n", reply->str);
    freeReplyObject(reply);

    reply = redisCommand(c,"INCR counter");
    printf("INCR counter: %lld\n", reply->integer);
    freeReplyObject(reply);
    /* again ... */
    reply = redisCommand(c,"INCR counter");
    printf("INCR counter: %lld\n", reply->integer);
    freeReplyObject(reply);

    /* Create a list of numbers, from 0 to 9 */
    reply = redisCommand(c,"DEL mylist");
    freeReplyObject(reply);
    for (j = 0; j < 10; j++) {
        char buf[64];

        snprintf(buf,64,"%d",j);
        reply = redisCommand(c,"LPUSH mylist element-%s", buf);
        freeReplyObject(reply);
    }

    /* Let's check what we have inside the list */
    reply = redisCommand(c,"LRANGE mylist 0 -1");
    if (reply->type == REDIS_REPLY_ARRAY) {
        for (j = 0; j < reply->elements; j++) {
            printf("%u) %s\n", j, reply->element[j]->str);
        }
    }
    freeReplyObject(reply);

    return 0;
}

7. Sample Monitor

Redis

Redis is an open source (BSD licensed), in-memory data structure store, used as database, cache and message broker. It supports data structures such as strings, hashes, lists, sets,sorted sets with range queries, bitmaps, hyperloglogs and geospatial indexes with radius queries. Redis has built-in replication, Lua scripting, LRU eviction, transactions and different levels of on-disk persistence, and provides high availability via Redis Sentinel and automatic partitioning with Redis Cluster.

1. Windows 용 redis

https://github.com/dmajkic/redis/downloads

2. execute redis-server.exe

3. execute redis-cli.exe