【轉】redis C接口hiredis 簡單函數使用介紹

from : http://blog.csdn.net/kingqizhou/article/details/8104693

 

hiredis是redis數據庫的C接口，目前只能在linux下使用，幾個基本的函數就可以操作redis數據庫了。

 

函數原型：redisContext *redisConnect(const char *ip, int port)

說明：該函數用來連接redis數據庫，參數為數據庫的ip地址和端口，一般redis數據庫的端口為6379

該函數返回一個結構體redisContext。

 

函數原型：void *redisCommand(redisContext *c, const char *format, ...);

說明：該函數執行命令，就如sql數據庫中的SQL語句一樣，只是執行的是redis數據庫中的操作命令，第一個參數為連接數據庫時返回的redisContext，剩下的參數為變參，就如C標准函數printf函數一樣的變參。返回值為void*，一般強制轉換成為redisReply類型的進行進一步的處理。

 

函數原型void freeReplyObject(void *reply);

說明：釋放redisCommand執行后返回的redisReply所占用的內存

 

函數原型：void redisFree(redisContext *c);

說明：釋放redisConnect()所產生的連接。

 

下面用一個簡單的例子說明：

#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <stdarg.h>
#include <string.h>
#include <assert.h>
#include "hiredis.h"

void doTest()
{
    //redis默認監聽端口為6387 可以再配置文件中修改
    redisContext* c = redisConnect("127.0.0.1", 6379);
    if ( c->err)
    {
        printf("Connect to redisServer faile:%s\n",c->errstr);
        redisFree(c);
        return ;
    }
    printf("Connect to redisServer Success\n");

    const char* command1 = "set stest1 value1";
    redisReply* r = (redisReply*)redisCommand(c, command1);

    if( NULL == r)
    {
        printf("Execut command1 failure\n");
        redisFree(c);
        return;
    }
    if( !(r->type == REDIS_REPLY_STATUS && (strcmp(r->str,"OK")==0 || strcmp(r->str,"ok")==0 ) ))
    {
        printf("Failed to execute command[%s]\n",command1);
        freeReplyObject(r);
        redisFree(c);
        return;
    }    
    freeReplyObject(r);
    printf("Succeed to execute command[%s]\n", command1);

    const char* command2 = "strlen stest1";
    r = (redisReply*)redisCommand(c, command2);
    if ( r->type != REDIS_REPLY_INTEGER)
    {
        printf("Failed to execute command[%s]\n",command2);
        freeReplyObject(r);
        redisFree(c);
        return;
    }
    int length =  r->integer;
    freeReplyObject(r);
    printf("The length of 'stest1' is %d.\n", length);
    printf("Succeed to execute command[%s]\n", command2);


    const char* command3 = "get stest1";
    r = (redisReply*)redisCommand(c, command3);
    if ( r->type != REDIS_REPLY_STRING)
    {
        printf("Failed to execute command[%s]\n",command3);
        freeReplyObject(r);
        redisFree(c);
        return;
    }
    printf("The value of 'stest1' is %s\n", r->str);
    freeReplyObject(r);
    printf("Succeed to execute command[%s]\n", command3);

    const char* command4 = "get stest2";
    r = (redisReply*)redisCommand(c, command4);
    if ( r->type != REDIS_REPLY_NIL)
    {
        printf("Failed to execute command[%s]\n",command4);
        freeReplyObject(r);
        redisFree(c);
        return;
    }
    freeReplyObject(r);
    printf("Succeed to execute command[%s]\n", command4);    


    redisFree(c);

}

int main()
{
    WSADATA wsaData;
    int nRet;
    if((nRet = WSAStartup(MAKEWORD(2,2),&wsaData)) != 0){
        printf("WSAStartup failed\n");
        exit(0);
    }
    doTest();
    return 0;
}

 

 

執行結果為：