in reply to multiple processes

Howdy, you don't mention on which OS you are running, but my experience on WIN systems is that FIFO's can be
tempremental, and not work if the listen end is opened before the talk end, which I suspect will happen in your case.

"That that is, is... for what is that but that? and is but is?" Shakespeare, Twelfth Night, Act IV, Scene 2

"Yet THAT which is not neither is nor is not That which is!" Frater Perdurabo (pseud. Aleister Crowley), Liber CCCXXXIII, The Book of Lies