redis C接口hiredis 简单函数使用介绍
hiredis是redis数据库的C接口，目前只能在linux下使用，几个基本的函数就可以操作redis数据库了。函数原型：redisContext *redisConnect(const char *ip, int port)
说明：该函数用来连接redis数据库，参数为数据库的ip地址和端口，一般redis数据库的端口为6379
该函数返回一个结构体redisContext。
函数原型：void *redisCommand(redisContext *c, const char *format, ...);
说明：该函数执行命令，就如sql数据库中的SQL语句一样，只是执行的是redis数据库中的操作命令，第一个参数为连接数据库时返回的redisContext，剩下的参数为变参，就如C标准函数printf函数一样的变参。返回值为void*，一般强制转换成为redisReply类型的进行进一步的处理。
函数原型void freeReplyObject(void *reply);
说明：释放redisCommand执行后返回的redisReply所占用的内存
函数原型：void redisFree(redisContext *c);
说明：释放redisConnect()所产生的连接。
下面用一个简单的例子说明：
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[*]#include
[*]#include
[*]#include
[*]#include
[*]#include
[*]#include
[*]#include
[*]
[*]void doTest()
[*]{
[*] //redis默认监听端口为6387 可以再配置文件中修改
[*] redisContext* c = redisConnect("127.0.0.1", 6379);
[*] if ( c->err)
[*] {
[*] redisFree(c);
[*] printf("Connect to redisServer faile\n");
[*] 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 && strcasecmp(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()
[*]{
[*] doTest();
[*] return 0;
[*]}
执行结果为：
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