from : http://blog.csdn.net/kingqizhou/article/details/8104693
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：
- #include <stdio.h>
- #include <stdlib.h>
- #include <stddef.h>
- #include <stdarg.h>
- #include <string.h>
- #include <assert.h>
- #include <hiredis/hiredis.h>
-
- void doTest()
- {
-
- 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：
