#!/bin/bash

PREF="$1"
shift

NPOUT=pipe.out
NPERR=pipe.err
mkfifo $NPOUT $NPERR

# Make two background sed processes
sed "s/^/$PREF/" <$NPOUT &
sed "s/^/$PREF/" <$NPERR >&2 &

# Run the program
"$@" >$NPOUT 2>$NPERR
rm $NPOUT $NPERR