redis-argv-hmset-example.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <hiredis.h>

int main(int argc, char **argv) {
    redisContext *c;
    redisReply *reply;
    const char *hostname = (argc > 1) ? argv[1] : "127.0.0.1";
    int port = (argc > 2) ? atoi(argv[2]) : 6379;

    struct timeval timeout = { 1, 500000 }; // 1.5 seconds
    c = redisConnectWithTimeout(hostname, port, timeout);
    if (c == NULL || c->err) {
        if (c) {
            printf("Connection error: %s\n", c->errstr);
            redisFree(c);
        } else {
            printf("Connection error: can't allocate redis context\n");
        }
        exit(1);
    }

    const char *key = "D11BA97064C28242739B7A5E06A3887B";
    const char *fields[] = {
        "content",
        "href",
    };
    const char *values[] = {
        "a plus b",
        "just_test",
    };
    // command + key + 2 * (number of field/value pairs)
    int argcount = 1 + 1 + 2 * 2;

    char **args = malloc(argcount * sizeof(char*));
    size_t *argvlen = malloc(argcount * sizeof(size_t));

    args[0] = malloc(strlen("HMSET"));
    argvlen[0] = strlen("HMSET");
    memcpy(args[0], "HMSET", strlen("HMSET"));

    args[1] = malloc(strlen(key));
    argvlen[1] = strlen(key);
    memcpy(args[1], key, strlen(key));

    for (int i=0; i<2; i++) {
        int argsidx = 2 + (i*2);
        args[argsidx] = malloc(strlen(fields[i]) * sizeof(char));
        args[argsidx+1] = malloc(strlen(values[i]) * sizeof(char));
        memcpy(args[argsidx], fields[i], strlen(fields[i]));
        memcpy(args[argsidx+1], values[i], strlen(values[i]));
        argvlen[argsidx] = strlen(fields[i]);
        argvlen[argsidx+1] = strlen(values[i]);
    }

    reply = redisCommandArgv(c, argcount, (const char**)args, argvlen);
    freeReplyObject(reply);


    /* Disconnects and frees the context */
    redisFree(c);

    return 0;
}