Implicit declaration of function 'select' is invalid in C99

编译一个别人的库的时候发现报下面这个错误。

1.Declaration of 'select' must be imported from module 'Darwin.POSIX.sys.time' before it is required
2.Implicit declaration of function 'select' is invalid in C99

这里记录一下解决办法，导入头文件即可：

#include <sys/time.h>