[cs631apue] Question about pipe

[hyan2]

Hi Professor,

I use pipe for the communication between child process and parent 
process when I implement POST response. I use two pairs pipe but I find 
that I must close the other pipe to get the right result. For example, I 
have two pipe in the child process, one is fd1[2] and one is fd2[2], if 
I use fd1[0] and fd2[1], then I must close fd1[1] and fd2[0]. In the 
parent process, I use fd1[1] and fd2[0] and I must close its pairs. If I 
don't close those pairs I find my browser is waiting for result and when 
I terminate the server's process, the browser will get the right result. 
If I close those pairs, every thing is ok. I am confused about this. 
Could you explain this problem？

Thank you.

-Han