How to send EOF to the popen(3) pipe?

[Yuri]

Is there a way to send the EOF to popen(3) pipe?

Imagine the situation when the child process works in a stream fashion, 
processes objects one by one, and stops on EOF from stdin. One has to be 
able to send EOF to get to the end of the last processed object. 
Otherwise reading from the descriptor will generally block.

Linux man page says that popen is unidirectional on Linux. But FreeBSD 
supports bi-directional popen.

Yuri