Aqui está um teste rápido que eu fiz:
mkfifo foo
yes "Process 1 reporting" > foo & yes "This is process 2" > foo &
awk '!a[$0]++' < foo
E a saída que recebi do awk:
Process 1 reporting
Process 1 reportThis is process 2
This is process 2
This is pring
Process 1 reportocess 2
ing
ocess 2
This is prProcess 1 reporting