//Four functions dlopen(), dlsym(),dlclose(),dlerror() implementing the interface to the dynamic linking loader
const char *dlerror(void);
:当动态链接库操作函数执行失败时,dlerror可以返回出错信息,返回值为NULL时表示操作函数执行成功。
:The funtion returns a human readable string describing the most recent error that occured fromdlopen(),dlsym() or dlclose() since the last call to dlerror(). It returns NULL if no errors haveoccurred since initialization or since it was last called.
void *dlopen(const char *filename, int flag);
:dlopen用于打开指定名字(filename)的动态链接库,并返回操作句柄。