Stderr and stdout of external program

[peerreynders]

Welcome to the forum!

Have you had a look at this yet (if you were thinking about pipes)?

How can I send a process a message from a shell script?

Is there a straightforward way to send a message to my Elixir process from a bash script? To avoid the XY problem, I am trying to implement a pianobar eventcmd, which is a script that is run on each event (such as song change) and receives the majority of it’s input via stdin. Should I use a pipe? I could do an HTTP Request but that seems awfully inefficient.