Simple hiredis example. Compile with `gcc -Wall -ocheck-hiredis check_hiredis.c -lhiredis`

check_hiredis.c

#include <stdlib.h>
#include <hiredis/hiredis.h>

int main() {

    redisContext *c = redisConnect("127.0.0.1", 6379);

    // Short circuit if we fail to allocate a redisContext or if it
    // reports an error state.
    if (c == NULL || c->err) {
        fprintf(stderr, "Error:  Couldn't connect to Redis (%s)\n",
                c && c->err ? c->errstr : "Unknown error");
        exit(1);
    }

    printf("Connected...\n");

    redisReply *reply;

    // You really shouldn't need this (redisReply*) typecast in C.
    reply = (redisReply*)redisCommand(c, "PING");

    // Now make sure our reply is not NULL and it is a STATUS reply.
    if (reply == NULL || reply->type != REDIS_REPLY_STATUS) {
        fprintf(stderr, "Error:  NULL or wrong type from PING!\n");
        exit(1);
    }

    // Now you know you have a reply and it's the right type
    printf("Reply: %s\n", reply->str);

    // Clean up memory.
    freeReplyObject(reply);
    redisFree(c);

    return 0;
}