1、同步调用：

#include <stdio.h>
#include "hiredis/hiredis.h"

int main() {
    redisContext *c = redisConnect("127.0.0.1", 6379);
    if (c == NULL) {
        printf("Can't allocate redis context\n");
        return 1;
    }
    if (c->err) {
        printf("Error: %s\n", c->errstr);
        return 1;
    }
    printf("redisConnect success!\n");

    char *key = "hello";
    char *val = "redis";
    redisReply *reply = redisCommand(c, "set %s %s", key, val);
    if(reply->type == REDIS_REPLY_STATUS) {
        printf("set %s %s\n", key, val);
    }
    freeReplyObject(reply);

    reply = redisCommand(c, "GET %s", key);
    if (reply->type == REDIS_REPLY_STRING) {
        printf("get %s\n", reply->str);
    }
    freeReplyObject(reply);

    redisFree(c);

    return 0;
}

输出：

redisConnect success!
set hello redis
get redis

 
 
2、Pipelining：

#include <stdio.h>
#include "hiredis/hiredis.h"

int main() {
    redisContext *c = redisConnect("127.0.0.1", 6379);
    if (c == NULL) {
        printf("Can't allocate redis context\n");
        return 1;
    }
    if (c->err) {
        printf("Error: %s\n", c->errstr);
        return 1;
    }
    printf("redisConnect success!\n");

    redisReply *reply = NULL;
    redisAppendCommand(c,"set hello redis");
    redisAppendCommand(c,"GET hello");

    redisGetReply(c,&reply);
    if(reply->type == REDIS_REPLY_STATUS) {
        printf("set hello redis\n");
    }
    freeReplyObject(reply);

    redisGetReply(c,&reply);
    if (reply->type == REDIS_REPLY_STRING) {
        printf("get %s\n", reply->str);
    }
    freeReplyObject(reply);

    redisFree(c);

    return 0;
}

输出：

redisConnect success!
set hello redis
get redis

 
 
3、异步调用：

#include <stdio.h>
#include <signal.h>
#include <string.h>
#include "event2/event.h"
#include "hiredis/adapters/libevent.h"

void getCallback(redisAsyncContext *c, void *r, void *privdata) {
    redisReply *reply = r;
    if (reply == NULL) return;
    printf("argv[%s]: %s\n", (char*)privdata, reply->str);

    /* Disconnect after receiving the reply to GET */
    redisAsyncDisconnect(c);
}

void connectCallback(const redisAsyncContext *c, int status) {
    if (status != REDIS_OK) {
        printf("Error: %s\n", c->errstr);
        return;
    }
    printf("Connected...\n");
}

void disconnectCallback(const redisAsyncContext *c, int status) {
    if (status != REDIS_OK) {
        printf("Error: %s\n", c->errstr);
        return;
    }
    printf("Disconnected...\n");
}

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 == NULL) {
        printf("Can't allocate redis context\n");
        return 1;
    }
    if (c->err) {
        printf("Error: %s\n", c->errstr);
        return 1;
    }
    printf("redisAsyncConnect success!\n");

    redisLibeventAttach(c,base);
    redisAsyncSetConnectCallback(c,connectCallback);
    redisAsyncSetDisconnectCallback(c,disconnectCallback);
    redisAsyncCommand(c, NULL, NULL, "SET key %b", argv[argc-1], strlen(argv[argc-1]));
    redisAsyncCommand(c, getCallback, (char*)"end-1", "GET key");
    event_base_dispatch(base);
    return 0;
}

输出：

$ ./hiredis_test 2019
redisAsyncConnect success!
Connected...
argv[end-1]: 2019
Disconnected...

 
 
参考文献：
hiredis源代码的README文件：
https://github.com/redis/hiredis/README.md
hiredis异步调用：
https://github.com/redis/hiredis/examples/example-libevent.c