hiredis redisCommand 为 Raspberry Pi 4 上的所有内容返回 null

Question

我有带有最新 raspbian 和更新软件的 Raspberry pi 4B。我使用他们的安装说明从 github 源安装了hiredis 库。当我尝试在普通计算机上运行以下代码时，一切正常，但在 Raspberry Pi 4B redisCommand 上总是返回 null。当我使用SET 命令时，数据库会更新。

代码：

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


int main (int argc, char **argv) {
    redisReply *reply;
    redisContext *c;

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


    /* Set a key */
    reply = redisCommand(c,"SET %s %s", "test", "Hello World");
    printf("SET: %s\n", reply->str);
    printf("error: %s\n", c->errstr);
    freeReplyObject(reply);

    redisFree(c);
    return 0;
}

编译：gcc redis-test-rw.c -o redis-test-rw -g -lhiredis

运行：

pi@rpi:~ $ ./redis-test-rw 
SET: (null)
error: 
pi@rpi:~ $

此调用后的 Redis：

pi@rpi:~ $ redis-cli 
127.0.0.1:6379> GET test
"Hello World"
127.0.0.1:6379> 
pi@rpi:~ $ 

Redis MONITOR 命令：

127.0.0.1:6379> MONITOR
OK
1577573389.883836 [0 127.0.0.1:47228] "SET" "test" "Hello World"

我对此感到非常困惑，因为在以前的 Raspberry pi 3B 上，hiredis 没有问题，而在计算机上也没问题。

感谢您的提前！

编辑： Valgrind 报告：

$ valgrind ./redis-test-rw 
==21969== Memcheck, a memory error detector
==21969== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==21969== Using Valgrind-3.15.0 and LibVEX; rerun with -h for copyright info
==21969== Command: ./redis-test-rw
==21969== 
==21969== Invalid read of size 8
==21969==    at 0x4865004: ??? (in /usr/lib/arm-linux-gnueabihf/libarmmem-v7l.so)
==21969==  Address 0x49f964c is 36 bytes inside a block of size 42 alloc'd
==21969==    at 0x4847690: malloc (vg_replace_malloc.c:309)
==21969==    by 0x48907BB: redisvFormatCommand (in /usr/lib/arm-linux-gnueabihf/libhiredis.so.0.14)
==21969== 
SET: (null)
error: 
==21969== 
==21969== HEAP SUMMARY:
==21969==     in use at exit: 0 bytes in 0 blocks
==21969==   total heap usage: 23 allocs, 23 frees, 1,913 bytes allocated
==21969== 
==21969== All heap blocks were freed -- no leaks are possible
==21969== 
==21969== For lists of detected and suppressed errors, rerun with: -s
==21969== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)

Answer 1

编译此示例代码并验证结果：

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

int main (int argc, char **argv) {
    redisReply *reply;
    redisContext *c;

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

    /* PINGs */
    reply = redisCommand(c,"PING %s", "Hello World");
    printf("RESPONSE: %s\n", reply->str);
    printf("error: %s\n", c->errstr);
    freeReplyObject(reply);

    redisFree(c);
    return 0;
}

应该打印：

RESPONSE: Hello World
error: