管道的使用——mkfifo

 

A process can open a FIFO in non-blocking mode. In this case，

opening for read only will succeed even if no-one has opened on the write side yet;

opening for write only will fail with ENXIO (no such device or address) unless the other end has already been opened.

 

在non-blocking模式下，进程可以用只读模式打开管道（即便另一端没有用写模式打开）；

但是不能用只写模式打开管道（错误为ENXIO， no such device or address），除非另一端已经用读模式打开了。