在编写接口API时，发现中文字utf8输入的在linux下采用c读取显示为”??”问号，这是由于编码造成的。很简单的两个地方做修改就搞定。

1.先找到mysql的my.cnf配置文件/etc/my.cnf编辑添加

[mysqld]

default-character-set=utf8

2.在程序中添加 mysql_set_character_set(&db,”utf8″); 语句

例子：kiccleaf.c 文件

#include

//这里需要找到相应地址不知道可以用“ find / -name mysql.h ”查询

#include "/usr/include/mysql/mysql.h"

int main()

{

MYSQL db;/*connector*/

MYSQL_RES* result;/*result buffer*/

MYSQL_ROW row;/*one row of the result*/

int i;

if(mysql_init(&db) ==NULL)

{

fprintf(stderr,"Fail to initialize the db.\n");

return -1;

}

if(!mysql_real_connect(&db,"localhost","root","password","kiccleaf",3306,NULL,0))

{

fprintf(stderr,"Fail to connect to the server");

return -1;

}

//添加字符集防止乱码

mysql_set_character_set(&db,"utf8");

if(mysql_query(&db,"SELECT * FROM user") != 0)

{

fprintf(stderr,"Fail to query the db for information.\n");

return -1;

}

if ((result = mysql_store_result(&db)) == NULL)

{

fprintf(stderr,"Fail to get the result.\n");

return -1;

}

while((row=mysql_fetch_row(result)) != NULL)/*fetching each row*/

{

puts("================================================");

printf("id: %s\n",row[0]);

printf("name: %s\n",row[1]);

printf("pwd: %s\n",row[2]);

printf("flag: %s\n",row[3]);

puts("================================================");

}

mysql_free_result(result);

mysql_close(&db);

return 0;

}

编译时也会出现问题，可以添加参数 “-lz /usr/lib/mysql/libmysqlclient.so.15.0.0”

gcc -o kiccleaf -g kiccleaf.c -lz /usr/lib/mysql/libmysqlclient.so.15.0.0

原来乱码的情况

[root@kiccleaf c]# ./kiccleaf

================================================

id: 0000000001

name: ???

pwd: 123456

flag: 0

================================================

================================================

id: 0000000002

name: ???

pwd: 654123

flag: 0

================================================

================================================

id: 0000000003

name: ???

pwd: 789456

flag: 0

================================================

================================================

id: 0000000004

name: ???

pwd: 456321

flag: 0

================================================

添加字符集后输出结果：

[root@kiccleaf c]# ./kiccleaf

================================================

id: 0000000001

name: 测试1

pwd: 123456

flag: 0

================================================

================================================

id: 0000000002

name: 测试2

pwd: 654123

flag: 0

================================================

================================================

id: 0000000003

name: 测试3

pwd: 789456

flag: 0

================================================

================================================

id: 0000000004

name: 测试4

pwd: 456321

flag: 0

================================================