Os pipes nomeados aceitam a saída de qualquer pessoa (se as permissões permitirem)
#!/bin/bash
mkfifo -m 666 /tmp/myfifo.pipe
( echo 'Proc1' 1> /tmp/myfifo.pipe ) &
PID1=$!
( echo 'Proc2' 1> /tmp/myfifo.pipe ) &
PID2=$!
( echo 'Proc3' 1> /tmp/myfifo.pipe ) &
PID3=$!
cat </tmp/myfifo.pipe > result.txt
wait $PID1 $PID2 $PID3
rm -f /tmp/myfifo.pipe