고기맛을 알아버린 스님

mysql header file dir : /usr/local/mysql/include/mysql

mysql library file dir : /usr/local/mysql/lib/mysql

$ uname -a

Linux linux 2.4.22 #1 Mon Mar 22 16:01:12 KST 2004 i686 unknown

$ mysql --version

mysql  Ver 11.18 Distrib 3.23.57, for pc-linux (i686)

$ cat connect.c

#include <stdio.h>

#include <mysql.h>

int main() {

  MYSQL sql;

  mysql_init(&sql);

  if (!mysql_real_connect(&sql, NULL, "db_user", "db_pw", NULL, 3306, (char*)NULL, 0)) {

     printf("Connect is fail -.-;;;;;;;\n");

     exit(100);

  } else {

     printf("Connect is success ㅋㅋㅋ !!!\n");

  }

  mysql_close(&sql);

  return 0;

}

^D

$ gcc -o connect connect.c -I/usr/local/mysql/include/mysql -L/usr/local/mysql/lib/mysql -lmysqlclient

$ echo $?

0

$ ./connect

/home/xxx/src/c++/connect: error while loading shared libraries: libmysqlclient.so.10: cannot load shared object file: No such file or directory

$ ls -l /usr/local/mysql/lib/mysql

...

lrwxrwxrwx    1 root     mysql          24 Aug 18  2003 libmysqlclient.so -> libmysqlclient.so.10.0.0*
lrwxrwxrwx    1 root     mysql          24 Aug 18  2003 libmysqlclient.so.10 -> libmysqlclient.so.10.0.0*
-rwxr-xr-x    1 root     mysql      169525 Aug 18  2003 libmysqlclient.so.10.0.0*
...

$

Oh, Shit !!!!!!!!!!!!

http://mysql.com

If you are learning to use the c API and your executable produces an error like "ld.so.1: test: fatal: libmysqlclient.so.12: open failed: No such file or directory"
then you need to set the environment variable $LD_LIBRARY_PATH to read the shared library file. E.g., for csh /tcsh
setenv LD_LIBRARY_PATH /opt/gnu/lib:/export/local/mysql/lib/mysql

$ cd ~

$ vi . .bash_profile

...

LD_LIBRARY_PATH=/usr/local/mysql/lib/mysql

...

export LD_LIBRARY_PATH

:wq

$ . .bash_profile

$ cd ~/src/c++

$ gcc -o connect connect.c -I/usr/local/mysql/include/mysql -L/usr/local/mysql/lib/mysql -lmysqlclient

$ ./connect

Connect is success ㅋㅋㅋ !!!

$

///////////////////////////////////////////////////////

Attention !!!

The 'connect' that executable file's owner is xxx, and use shared library. Because of user xxx set environment variable, the variable 'LD_LIBRARY_PATH' will be loading, while system init process is begining.

This mean that execute file only user xxx can be running.

If other user execute this file, you will suffer a -.- like me in runtime...